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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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November 17 2010

A Visual Guide to Yams and Sweet Potatoes (plus How They Fit Into a Primal Eating Plan)

By Mark Sisson
180 Comments

Quick. What’s a suitable, Primal source of post-workout carbohydrates? If the title of this post and the picture to the right didn’t give you a hint then ask your nearest Primal enthusiast and they’ll tell you without batting an eye, “yams and sweet potatoes”. If, for whatever reason, you need some extra carbs “yams and sweet potatoes” is the answer. Everyone knows this, but is it true?

That’s what I’ll be exploring in today’s post. But first, what are yams and how do they differ from sweet potatoes?

In the United States, most tubers sold as yams are actually members of the sweet potato family. Your Garnets, your Jewels, the “yams” with the rich orange flesh and reddish-brown exterior, are, botanically, sweet potatoes. In fact, it’s quite likely that the vast majority of my readers – even the active ones including more carbohydrate in their diets – have never tasted a true yam. The reason for this discrepancy is simple marketing: back in the mid-20th century, when orange-fleshed sweet potatoes were introduced into the United States, they were labeled “yams” to avoid confusion with the common white-fleshed sweet potato Americans were already enjoying. “Yam” was derived either from the Spanish “name” or Portuguese “inhame,” both of which come from the Wolof word “nyam,” which means “to sample” or “to taste.” Another African language uses “yamyam” for “to chew,” which should give you some idea of the starchy tuber’s importance in local diets – as well as the level of mastication required for its consumption.

Sweet potatoes, or Ipomoea batata, are native to South America, where they were domesticated at least 5000 years ago. They’re also common in Polynesia, and radio carbon dating of sweet potato remains in the Cook Islands places them at 1000 AD, with most researchers figuring they date back to at least 700 AD. The Peruvian Quechua word for sweet potato is kumar, while it’s called the remarkably similar kumara in Polyenesia, prompting speculation that early South American voyagers actually introduced the tuber to the South Pacific. At any rate, they’re delicious, they’re eaten everywhere, and they have a lengthy tradition of being consumed by healthy people.

Real yams hail from the Dioscorea family of perennial herbaceous vines and include dozens of varieties, some of which grow to over eight feet long and weigh nearly two hundred pounds. Now that’s a carb refeed!

Anyway, since most of us will be coming across sweet potatoes either disguised as yams or labeled correctly, let’s direct our attention to the various properties of the different sweet potato varieties.

Sweet Potatoes

The Classic Sweet Potato

This is probably what most of you picture when you think of a sweet potato – light tan skin, slightly yellow interior. It’s creamy, almost like a Yukon gold potato, and slightly sweet.

Basic sweet potatoes are strong sources of beta-carotene, manganese, and copper. A small one has 22g carbs and 3g fiber (food for your gut flora), making it the perfect post-workout snack. Amazing with cinnamon.

The “Yams”

Garnet, Jewel, Beauregard: these are the orange fleshed, reddish-brownish-orangish skinned sweet potatoes masquerading as yams. They’re even more common than the standard sweet potato, sweeter, and contain a bit more water (you can hear it escape when you bake them). These guys cook surprisingly well in a microwave. Pop ’em in, heat, mash lightly, load with butter and enjoy. You can expect to see quite a bit of them this coming Thanksgiving.

Okinawan Purple Sweet Potato

These are my current favorites. They are white skinned with a deep, brilliant purple interior that becomes velvety smooth and incredibly sweet when baked. Even better, the purple pigment is due to the vast numbers of anthocyanins – the very same beneficial antioxidant pigments that provide blueberries their brilliant color and health benefits. According to this entirely unbiased source, Okinawan sweet potatoes contain 150% more anthocyanins than the same amount of blueberries. That sounds reasonable, and a good general rule is the purpler the potato (or bluer the berry), the greater the anthocyanin content.

Several studies show potential benefits to purple sweet potato anthocyanins: suppression of mouse brain inflammation; alleviation of brain aging; reduction in cognitive deficits, inflammation, and oxidative damage in aging mouse brains; potential suppression of neurodegenerative cell death, as in Alzheimer’s; protection against acetaminophen-induced liver damage in mice. In human males with borderline hepatitis, a beverage infused with purple sweet potato anthocyanins “significantly decreased the serum levels of hepatic biomarkers”. Plus, the long-lived, fairly healthy Okinawans have traditionally used Okinawan purple sweet potatoes as a staple food. All the evidence seems to support their status as a healthy, delicious tuber.

There’s another variety that looks extremely similar but has a lightly violet interior streaked with white. It’s starchier and far drier than the Okinawans, and it doesn’t taste nearly as good. If you go looking for Okinawan potatoes in Asian supermarkets (which is the only place I’ve been able to find them consistently), inspect them carefully before buying. I once saw an old Chinese woman at one of these places snap the end of each potato off with her fingernail to check the color inside; this method works well, is relatively inconspicuous, and it’s a good way to make sure you’re getting the true Okinawan sweet potato. Just look for the deep purple flesh.

Japanese Sweet Potato, or Satsumaimo

Another Asian market mainstay is the satsumaimo, or Japanese sweet potato (can you tell I’ve been availing myself of the local ethnic markets?). I actually don’t care for this one. It’s just too sweet. Once you get it into the oven and the sugars start caramelizing, it becomes way too much for my palate. It’s honestly like eating dessert, which probably makes it sound pretty alluring for some. Look for purplish skin with a light interior (that turns golden brown with caramelizing). Give it a shot with some salty butter and maybe a dash of cinnamon and nutmeg if you want something sweet.

Yams

Dioscorea rotunda/cayenensis – The Common African Yam; “White Yam”; “Yellow Yam”

This is the true yam, with over 200 varieties in existence. Traditional preparation takes many forms, but the most common method is peeling and boiling. Fufu is mashed yam mixed with sauces, usually palm oil based. There’s also the practice of drying raw yam and smashing it into a powder, or flour, or, I dunno, maybe a big pile of starch granules (sound familiar?). This is called elubo. Though folks in the States and Europe rarely see it, it’s one of the most widely cultivated crops on the African continent, and by far the most popular yam in terms of sheer numbers. Look for it in African or Caribbean markets.

D. alata – The Purple Yam; “Water Yam”; “Winged Yam”

The purple yam was originally cultivated in Southeast Asia and is now the most widely distributed variety. It’s grown in Africa, Asia, the Pacific islands, the Caribbean, and it’s even wormed its way into the southern United States as a highly invasive marauding species. I suspect this may be the imposter I encountered when looking for Okinawan sweet potatoes, although the purple yam has its own benefits: one study found replacing rice with D. alata in the diets of postmenopausal women improved blood lipids (reduced LDL oxidation) and helped normalize sex hormones (increases in sex hormone binding globulin, estrone, and estradiol; a reduction in the total testosterone::SHBG ratio). A similar study with true sweet potatoes instead of yams did not have this effect. I’m not a postmenopausal woman, but maybe I’ll give it a shot next time.

D. opposita – “Chinese Yam”; Japanese “Mountain Yam”

This is cultivated in China, Japan, and Korea, but it’s made its way into the southern US, also as an invader (PDF) – though US Chinese yam plants don’t appear to bear any edible yams. Too bad. It’s one of the only true yams edible raw (the Japanese serve grated raw D. opposita after lightly soaking it in a vinegar-water solution to neutralize the oxalates in the skin). The Chinese, who call it shanyao, have used it as an herbal medicine for thousands of years in the treatment of liver and kidney disease. In rats, shanyao extract seems to decrease liver and kidney damage related to alcohol abuse and acetaminophen abuse. I’ve seen this in Asian supermarkets here in LA, but have never tried it myself. It’s quite tasty served alongside sashimi, however.

For all these tubers, my go-to method of cooking is to toss a handful in the oven at 400 degrees F and check on them after about an hour. Some people prick them a couple times before cooking, but I usually don’t. If you’re in a rush, wrap them in paper towels and heat them in the microwave for a couple minutes before finishing them in the oven. If they’re oozing goo (listen for the squeal of escaping steam) or soft to the touch, they’re probably ready. That goo burns, so make sure you use either foil or a cookie sheet to protect your oven. This method has served me well for any sweet potato or “yam” I’ve come across. Some may take a little longer, some a little shorter, but the poke, prod, and goo methods are reliable and field-tested.

They keep well in the fridge for up to a week, so active folks eating more carbs can make a bunch at once for easy refeeds. Just reheat in a 200 degree oven or eat cold right out of the fridge. You can also smash the cooked, chilled tubers into a flat pancake and fry that up with some butter, coconut oil, and cinnamon. Very tasty.

Traditionally, sweet potato and yam skins are removed before consumption, so I err on the side of caution and do the same. I doubt a bit of skin is going to hurt you, though, if you decide to eat it. Most of the anti-nutrients in potatoes can be found in the skin, and it seems logical to assume the same is true for yams and sweet potatoes.

Organic or conventional?

Generally, I opt for organic, but it may not matter as much with sweet potatoes. Sweet potatoes consistently show up with lower pesticide residues, especially when compared to normal potatoes. As always, though, the best is locally grown in rich soil. Big farms may have good soil and growing practices, but at least when you buy from small farms at farmers’ markets, you get to meet the grower and ask them about their farm. Conventionally grown or big-time organic tubers may be perfectly acceptable, but they’ll be missing key minerals and micronutrients if the soil they were grown in is deficient and depleted. Plus, I find small farms produce tastier stuff as a general rule.

Sweet Potato Leaves

Though I haven’t seen them in any LA stores, sweet potato leaves are apparently quite nutritious and commonly eaten in some African countries. This study (PDF) did the work for us, examining the nutritive and anti-nutritive properties of the leaves. Highlights include low levels of cyanide (30.24mg/100g), phytic acid (1.44mg/100g), and tannins (0.21mg/100g); high levels of magnesium (340mg/100g), calcium (28.44mg/100g), and manganese (4.65mg/100g). Oxalate content was pretty high, though, (308mg/100g), but half that of spinach (750mg/100g). These might be worth trying and treating like spinach or kale if you can get a hold of some.

Other Health Benefits

As we all know, foods aren’t just their macronutrient composition. Micronutrient matters as well, and it’s also important to see the food as exactly that: whole food, a package deal.

You might, for example, suppose that starchy sweet potatoes are absolutely horrible for patients with diabetes. But sweet potatoes aren’t just starch; caiapo, an extract of the standard sweet potato, was given to type 2 diabetics. After five months, they displayed greater glucose control, higher adiponectin, and lower fibrinogen. Another study on diabetic patients had similar results. It’s important to note that these were using non-caloric extracts, as opposed to actual sweet potatoes, but another study found that actual sweet potatoes were beneficial to diabetic rats. Things might be different for diabetics eating actual sweet potatoes (starch included), but I think it’s pretty clear that healthy people can eat them freely – just look at the Kitavans, who eat a ton of yams and sweet potatoes.

There are thousands of varieties of sweet potatoes and yams. It would be impossible to document them all, and foolish to try. Just know this: they are healthy, tasty, safe sources of starch (if you go for that kind of thing) that people have been eating for a long, long time. If you’re trying to lose weight, keeping your intake to the post-workout period is probably best. If you’re looking for a dense source of carbs, I can’t imagine a better option. Of course, always keep your total carb intake goals in mind if and when you add yams and sweet potatoes to your eating plan. For me, and I’d suspect most people reading, keeping carbs on the low end is high priority, and thus these starchy tubers are a welcome addition only every once and awhile and in moderation when they are added.

What do you think? Do you have a favorite sweet potato variety? Favorite preparation method? Are sweet potatoes part of your diet, and if so, how often do you eat them? Share your thoughts in the comment board and thanks for reading.

Photo Credit: Ganjin, deccanheffalump Flickr Photos
TAGS:  is it primal?

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180 thoughts on “A Visual Guide to Yams and Sweet Potatoes (plus How They Fit Into a Primal Eating Plan)”

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  1. Wow, thanks Mark! I had no idea there are so many types of yams. I suppose it’s one of the benefits of the world we live in: variety; although not all variations create the same benefits from a primal perspective, as you’re proving us here.

  2. My favorite way to eat sweet potatoes:

    Chop them into small squares (like with home fries), coat with a little olive oil, season with sea salt, pepper, cumin(critical spice), red pepper, chili powder, garlic powder…whatever spices you like, and roast for 30 minutes at 375 degrees or so. Think oven baked french fries made with sweet potatoes. Delicious! Hardest part is chopping them up while raw…gives you a good primal workout!

    1. This is how I do it too, except when I have more time I dice a couple of slices of bacon, fry them up, and toss the sweet potatoes with the bacon and its grease instead of olive oil. Add some diced red onions to the pan along with the spices and it’s heaven!

    2. My favorite way to eat sweet potatoes:

      Chop/slice in to home fries and season with a little olive oil, crushed chili pepper flakes and free or dry Thyme. Bake in a heated 375 degree over for 30 minutes. Enjoy………..so awesome

  3. I only see the orange fleshed varieties here in VA. I obviously need to look beyond the traditional grocers.

    Are there regional differences in the availability of these varieties? I want to try the lighter colored versions,including true yams, to see if they are less sweet. Asian grocers are not to be found nearby.

    1. In addition to the Asian grocers here in Baltimore, I have also found good varieties at Whole Foods, Trader Joe’s, and Wegmens. Also, if you ask (and know what you are looking for, specifically) Trader Joe’s will often order stuff for you that they might not normally carry.

  4. Wow, I love me some sweet potatoes. I get a bag of organic sweet potatoes at Trader Joe’s almost weekly. That and brocolli. They are just so yummy and naturally sweet.

    I can eat them plain. Sometimes with a dab of butter, or sprinkled with cinnamon. SO good. I like them fresh. I can’t seem to eat the ones in the cans. They’re too sweet for me, and probably not as healthy.

    It’s pretty neat to see the different varieties. Thanks for sharing.

  5. I agree that the purple ones are absolutely delicious. They seem to pair esepcially well with virgin coconut oil. YUM!

  6. This was a super informative (and yummy) post!

    I have cut back on my yams this season but I have a few in my “squah box” in the pantry and I will probably be baking a couple tonight now for sure.

    They are my go to dessert most days when I want a sweet treat.

    MY FAVORITE WAY to eat them is to slice them in quarters…place a bit of olive oil in my hands and oil them all over, a light sprinling of sea salt (skin side) and let them bake at 350 degrees for maybe an hour…they get all carmelized and oooey and gooey.
    You just peel them off the foil lined pan (when cool enough…oh how I’ve learned that the hard way too many times)

    smells like roasted marshmallows.

    dang…now I need to go bake some!

    Thanks for all the information on yams and sweet potatoes!

  7. When I was in Nigeria a couple of years ago, one of the traditional foods in the village was “pounded yam” and while I was confused at the time, this article now explains why their yams looked NOTHING like what I was used to seeing. Thanks Mark!

  8. Excellent post!! Couple of add’l points…

    All tubers are super high in potassium and act as good alkalinizing vegetables.

    Richard Wrangham has a great book out called Catching Fire: How Cooking Made Us Human that argues that the big change in tooth/jaw size at 1.8 million years ago (Homo habilis to Homo erectus transition)was due to our learning to control fire and thus use the abundant previously inedible tubers found in the open, dry savannah, as a stable source of calories- the staple of their diet basically.

    Meat and aboveground fruits and vegs were too variable in abundance to be their mainstay- tubers must have been the fall-back food, allowing them to move out into the harsher savannah environment.

    Love to know how much they have been bred over the years for higher glycaemic indexes? I found some papers on “native” root glycaemic indexes, but its still not clear how “wild” they really are, since man has basically been “cultivating” them for millions of years.

  9. A lady at work shared some Okinowan sweet potatoes with me and they’re delicious. Very filling too, if you’re used to low starch Primal eating.

  10. I roast sweet potato discs at 400F with olive oil, S&P, some garlic powder, and most importantly, ROSEMARY. Delish.

  11. Anyone know of any good sources for the Okinawan purples? Preferably a source you have personally used and delivers to the East Coast of the US….

  12. Very nice post, Mark 🙂
    I have yet to taste sweet potatoes… never had the occasion before.

    I like the way the japanese ones look 🙂

  13. Thanks for this. Every time I go in Wholefoods, I am fooled. What is a yam? What is a sweet potato? Only last night I fed my kids a sweet potato, my husband said it was yam and now I see I was right all along. The people in WF don’t know what’s right either.

    1. I work at whole foods in the produce department and I did actually know this. Haha. It’s really difficult to explain this to people. Ill be referring to this article from now on. 🙂

  14. I don’t really eat them, too carby for anything except periworkout. I do pumpkin and spaghetti squash instead with the occasional delicata.

  15. we make fufu in the Caribbean too. you can make it out of yucca as well.

  16. Ooohh that’s exactly how I make them – slightly different spices! So good! Just this last time I did use the Japanese version and I have to say I did like it a lot. Sweet tooth!

  17. One of my favorite sweet potatoes, I don’t think was mentioned here. It has a yellow skin and yellow flesh when cooked. It’s not overly sweet, but has more of a savory kind of flavor. It also has a more dense flesh, almost like a potato. So it’s not as mushy as the reddish/orange ones.

  18. Ooh, I’ll be looking for that purple variety!

    I agree about the Japanese sweet potato. If I want something that sweet, I’ll have some chocolate pudding.

  19. The japanese ones need different recipes.

    Baked they are desserts, even in Japan. If you want to eat them with hearty dishes you need peel them first and cook them in a sour+salty broth.

  20. I ate lots of true sweet potato leaves as a Peace Corps volunteer in Tanzania, East Africa. If you grow your own, just pull off a handful or two of leaves, and saute in a bit of butter or coconut oil. The leaves will soften up nicely and exude some mucilaginous stuff (like okra), be prepared. Pumpkin and winter squash leaves of all types were also regularly eaten, some winter squashes were planted solely for their leaves!

  21. I’m curious to know if anyone has ever used sweet potatoes in a crock pot (slow cooker) in lieu of potatoes. I just bought an entire grass-fed steer and with all of the roasts I am in need of some more ingredients for my slow roasts. Thanks

    1. Yes! Cooking sweet potatoes in a slow cooker works wonderfully 🙂 I always add them toward the end so they’re not too mushy (for recipes 6+ hours).

  22. Me? I’m a yam fan! I love to chop, boil and mash. Load ’em up with butter, add S&P and enjoy! I actually find sweet potatoes to be too sweet tasting for me. But the yams I buy are much more mild flavored.

  23. Interesting. In New Zealand we call this vegetable a yam… http://en.wikipedia.org/wiki/Oca

    It is a completely different family of vegetable again! Usually boiled or roasted it has a beautiful slightly tart flavour.

    (P.S. Here in NZ we usually refer to sweet potatoes by the traditional M?ori name of k?mara).

    What’s in a name eh? 🙂

    1. At home in Australia we call them Kumara as well, must have got it from you guys.

  24. Fantastic post! I’ve been eating white rice for my post-workout carb meals since your recent post on them, but I much prefer to eat a non-grain source. Gonna go stock up on some of the orange-reddish kind!

  25. As a kid, I despised sweet potatoes with a passion. My little chubby self loved standard russet potatoes though.

    These days, it’s pretty much the opposite. My wife and I have sweet potatoes maybe once a week (chopped into long “fries”, roasted in the oven with evoo or butter and salt/pepper & cayenne). They’re one of our favorites!

    1. When we were kids in the 40’s we would take a cooked sweet potato and biscuit to school for lunch cotton share croppers never had much money. But plenty home grown fruits veggies and meat all organic

  26. i just HAD to go eat a sweet potato for my lunch, this post was so inspiring…. to me, sweet potatoes are like the nut-based breads i make these days — in large part, a vehicle for eating BUTTER.

  27. Awesome post!!
    I’m a busy stay-at-home mom who likes to stay active and is still nursing a 16 month old. Sweet potatoes have been an amazing source of quick and effective energy when I feel the need for some extra carbs. I generally pop a fake ‘yam’ in the microwave, set it on high for 5-9 minutes (depending on the size) and eat it mashed with butter and cinnamon. It’s fast and VERY delicious and satisfying. I’ve found that I can safely fit them in to my Primal eating plan about 3-4 times a week.
    This post made me hungry!! 🙂

  28. where in the LA area can you get purple sweet potatoes? I’d love to make some fries out of them!

    1. Try an Asian supermarket, like Ranch 99. San Gabriel Valley is full of stores that carry them. Hawaii Supermarket is absolutely worth a trip; they’ve got cheap NZ lamb, too.

      Nijiya is another option; there’s one on Sawtelle in West LA and one downtown – http://www.nijiya.com/

  29. As usual, you have inspired me to try something new. A trip to the Asian food store is definitely in store. I bet my kids would love those purple sweet potatoes. Especially if we made them into oven-baked chips like we do with the orange ones. That would make a nice veggie side-dish for kids who like finger foods!

  30. I eat them for breakfast. And I love them with spicy (cayenne) seasoned salt and pumpkin seeds for protein.

    For sweet potato leaves, just grow your own. Throw a sprouting sweet potato in a pot and it will produce greens all summer long. It’s a very attractive plant and makes good ground cover that blocks a lot of weeds. Then in the fall, you get some free sweet potatoes.

    They are a bit stringy and they wilt fast. And wilt to nothing when you cook them, more so even than spinach. They are not my favorite. But still, it’s a great free source of organic greens in the summer! And I like to add greens to all kinds of foods that wouldn’t normally have them (soups, curries, legumes) so wilting to nothing can be a plus.

  31. Great post Mark. I am a big fan of sweet potatoes, and have increased my consumption of them considerably. Since going primal I have lost over 50 lbs, and consider myself in the maintenance stage now. My activity level is through the roof, so I am definitely looking for good carbs to eat. I think the Okinawan purple sweet potato sounds amazing! Thanks for the tips.

    Cheers,
    Jordan

  32. My favorite cooking method, which is also super fast, is to cook the sweet potatoe in the microwave for 2-3 minutes until almost done. Then I slice them thin and cook them in a HOT skillet with coconut oil. I sprinkle them with garlic salt. Cook both sides. I like them almost burned. They are yummy, yummy!
    And to the person who asked about the slow cooker, I frequently use sweet pototoes in my crock pot. They are great. They do tend to break down a little faster than white pototoes, so if you are going to cook your meat for a really long time, you may want to put them in two hours after starting. I am making alot of soup this winter in the crock pot and I always put sweet potatoes in them.

  33. ‘Garnet, Jewel, Beauregard’ – These are sold as sweet potatoes, not yams in England. I have some at home right now, and I bought them as sweet potatoes.

  34. I cut the sweet potato into rounds..microwave them for three minutes…baste them with olive oil and finish the on the grill or broiler for a nice roasted taste..and fairly quick too…!

  35. My husband and I love sweet potatoes! One of our favorite dinners is to shred a medium sweet potato on a box grater. Cook in a pan on med-high with coconut milk, oil, salt and onions. When they’re almost done and crisping up, add crushed garlic and sausage. Then cook a couple eggs over easy with it. So delish!

  36. An awesome post, just as usual!!
    For those who haven’t discovered this yet, Sweet potato + coconut oil/butter + cinnamon is a Bomb!!! So good!!

  37. My spouse hates anything remotely sweet potato or yam. All the more for the rest of us! I like mine baked and dressed with butter, chives and s&p.

  38. I love sweet potatoes. I cube them in to about 3/4″ pieces, roll them in olive oil, then sprinkle Tony Chachere’s Creole Seasoning, and rosemary and then bake them in a 400 deg oven until soft.

  39. The classic sweet potato is my favorite!

    It is delicious with melted coconut oil or coconut butter and a sprinkle of sea salt!

    Another favorite is to add bit almond butter and cinnamon!

  40. I like to make sweet potato “fries” by slicing them thin (1/4″ fries), tossing them liberally with coconut oil and sea salt and a little black pepper, then bake them for 20 minutes at 425 degrees. As long as you make sure they are all in a single layer on the baking pan (not on top of each other), they will get nice and crispy. Mmmmm!

  41. Trust me on this one…

    Thinly slice sweet patatos or yams.
    Boil for a few minutes but do not let Them soften too much. Drain water.
    Stir in Coconut Oil, Basil, a bit of Garlic.
    Fry on low heat for a 5 or so minutes

    It’s off the wall how good this is..

    1. Dehydrate them for the best dog chews!Pet shops are selling them for a small fortune. Peel, cut in 1/2 lengthwise, the in 1/3″ slices.
      Put in your dehydater @ 135* till like rawhide.Or you can slow bake at 250*.Dogs go absolutley wild for theese treats. (Ive only tried the orange flesh variety)

      1. And don’t waste the peelings either – most of my veggie scraps go to my huskies. They adore sweetpotatoes. I’ve just turned my eldest (14 1/2) totally primal to see how he gets on and already he’s more perky.

  42. when i lived in asia the stems of sweet potatos were sold in the market and served in restaurants. they were delicious and i became quite fond of them. however, i never saw, nor was i ever served, the leaves. so i am wondering if different varieties have different tasting leaves. the tubers of course were ubiquitous. thanks for the post.

  43. I eat over a pound of yams (& Sp)a day..I´m really trying to gain some mass so no problem for now, my only concern is that my hands & feet have acquired an orangy tone, hope is nothing to worry about.

    Best dessert ever: baked sweet tater with pumpkin pie spice mix, eat cold add double cream & die.

  44. This is great Mark! I have often wondered about the differences.
    Thanks guys for all the recipe tips to 🙂

  45. Thanks, Mark, for another fabulously informative post. And thanks, everyone else, for all the suggestions on how to cook them sweet taters!

    My two favorite ways:
    1. One large onion plus one each of several different root veggies (sweet potatoes, “yams”, carrot, parsnip, rutabaga, etc.). Dice ’em all up, toss ’em in EVOO and bake or sauté until mashable. Mash. Eat. (if it’s too dry I’ll add meat juice from whatever meaty thing I just made)

    2. Baked sweet potato with butter and poached egg.

  46. My mother makes this lovely casserole of sliced yams, sausage, rosemary, garlic, and parmesan cheese. It’s pure magnificence, yet comforting too.

    I also make a chili using ground beef, sweet potatoes, chipotles in adobo sauce, and other ingredients. Sweet and smoky=yum!

  47. @Keturah

    That casserole dish really does sound magnificent.

    Personally, I avoid the microwave and I recommend the same for anyone else.

  48. The basic variety I’ve come across is what you term “The Yams” (we Aussies call it a sweet potato) although there’s one with a purplish skin which you see occasionally which I must try out of curiosity to see what’s inside. Today’s bit of totally useless information … (according to the Queensland State Government website) “We use sweetpotato as one word in line with an international agreement reached in Peru in 1994. This convention was agreed on to differentiate sweetpotato (Ipomoea batatas), family Convolvulaceae, from English or Irish potatoes (Solanum tuberosum), family Solanaceae.” It’s amazing what a difference a space makes.

  49. Interesting! I did not know there were so many varieties of potatoes. I have been avoiding carbs like the plague (which has helped me cut down to a six pack again), but adding Okinawan purple sweet potato (which look BA) into my diet would be fun!

  50. We had sweet potato leaves sold at the farmer’s markets for a couple months a while back. They are quite delicious. Tend to have the bitter quality kale has but the easy quick cooking spinach has. It is especially yummy in Asian dishes including Pho soup.

  51. There is an Asian/Hispanic market not too far from us that has a several varieties of sweet potatoes and true yams. I can’t wait to try some of these great varieties and recipes (after I finish my 30 days of “extreme Paleo”.)

  52. Mmm, the orangish sweet potatoes wrapped in foil and grilled indirectly over charcoal grill. Cook them until they’re fork-mashable. Great with chicken too!

  53. Yup I’ve tried all of the sweet potatoes listed here. I love the Okinawan purple sweet potato, they are to DIE for! Love to deep fry ’em in coconut oil for a tasty greasy snack!! Thanks for the info Mark :!

  54. Mark, Im currently trying to build muscle, Ive been primal for the past 5 months now. Im 18 btw, would this be a good primal muscle building food?

  55. I eat sweet potatoes quite a bit – fried, nuked, baked, slow cooked, you name it. The crispy skin was my favorite part of a white potato, so it was logical for me to try eating the skin of sweet potatoes and yams. They don’t crisp up like white potatoes but they’re still really delicious. I thought I was doing something good, since most of the nutrients and fiber are usually in the peel, aren’t they?? I haven’t experienced ANY adverse reactions. In fact, if I’m treating myself with a white potato, I’ll often scoop all the potato out and just eat the skin with loads of butter. Anyone else do this? Now I’m all paranoid about anti-nutrients.

    1. I love the skins too and have always eaten them… potato, sweet potato & yam skins. Infact I prefer potato skins to the insides. Never noticed any adverse reactions, but not I’m wondering about eating them. I’d like more info on it. Can’t seem to find enough on the Internet.

  56. I get the darkest-fleshed sweet potatoes, which, yes, in southern style, are called yams here.

    Scrub lightly and wipe with clean towel. Butter skin. Place on baking sheet and roast in 350F to 400F oven ’til well done. Can’t give exact time because size, thickness and age all enter in. They are done when the skin collapses because the flesh has shrunk and they leak dark caramelized juices.

    Remove from oven. Let sit for 15 to 30 minutes. Place each in a bowl. Slice crosswise and squeeze like a you would a regular baked potato. Top with 2 tbsp each of sour cream and walnuts. If you want to be really bad, drizzle with dark molasses.

  57. I recently discovered the sweet potato leaves here in Hong Kong. they are now my favorite. Even my 3 yr old who doesn’t like to chew on greens loves them.

    we imitate the Korean recipe of a spinach side dish, cook them lightly, mix in soy sauce, Korean chili powder, sesame, sesame oil, garlic powder, toss well and chill in fridge. we usually can’t wait for the chilling to take place, too yummy.

    apparently you can cultivate them at home.

  58. The purple ones are my favorite too, although it takes a 45 minute one way trip to the asian market to get them! I peel and shred the sweet potato, mix in an egg, a chopped green onion and some red pepper flakes then flatten them into pancakes and fry them in coconut oil…delish (you might need a tablespoon of coconut flour depending on the water content of the potato)!!! If you eat dairy a nice dollop of creme fraiche goes great with it as well!

  59. Thanks Mark,

    I am a Kenyan living in the States and never tire of explaining to my American friends the difference between sweet potatoes and yams. Almost all ‘yams’ so-labelled in the US are sweet potatoes. It’s very hard to find a true yam here. Sweet potatoes of all varieties and colors are a Kenyan staple. Delicious, affordable and healthy.

    Thank you for sharing!!!

  60. Mark, what are your thoughts on the “new” yam flour noodles No-Oodles? I believe they are made from an asian yam, but have been around in asian markets. Few carbs, but not much fiber or nutrition either. I have been ‘primal’ for about 5 years–every now and then, when a pasta craving hits, I have them. I am guessing they aren’t great nutritionally, but still might be a processed paleo option?

  61. Thank you Mark

    I look forward to your research about Microwaves….that was the only “little” detail in your wonderful report that I did not feel too happy about.I rightfully do not trust them and would not even want to destructure water by heating it in a microwave. No, no popcorn either –
    but – for all the main piece
    thank you so much
    Verena

  62. Sweet potatoes are actually easy to grow in your home garden. And did you know that the leaves of certain varieties are edible?

    1. Yes, we grow gobs of them every year…that is, we plant them and they grow themselves. Extremely low maintenance plants. Depending on the weather, we usually harvest from 150 to 400 pounds each year. We store them in our crawlspace (sort of like a root cellar) and eat them all year. We also grow our own sprouts from a dozen or so of the biggest ones, so we don’t even have to buy plants. Free healthy organically grown food!

  63. Mark I’ve been eating a ton of the “fake” yams lately to try and reverse weight loss (it’s so hard to add mass – my body just wants to shed it!).

    I would enjoy more posts on nutritious, high energy carbs in the future since I avoid rice, beans, corn, and all grains. Bok Choy and green beans aren’t sticking to my ribs!

  64. So why are these okay, but corn on the cob not? That is the only thing keeping me from going primal, I cannot give up the roasted in their husks in a fire corn!

    1. In terms of carbohydrate content, I would suspect they’re very similar. However, sweet potatoes and yams are tubers, corn is a grain. Grains don’t want to be eaten. Gluten, lectins, phytates…not cool. Read up! Plenty of info here.

    2. You can go primal and have a little corn now and then for the 20% of your 80/20! I’m a lacto primal and there is no way I’m about to give up my raw goat milk and various cheese, nor would I give up corn on the cob in the summer in Maine!

  65. Chop sweet potatoes into large pieces. Boil them until very soft. Get rid of water and mash em up. I add coconut milk, a little honey, raisins. Some nuts are also good. Def not low carb but maybe good for some post workout or cheat day.

  66. Had no idea there were so many varieties of sweet potato and yam.

    Here in New Zealand a sweet potato that we call kumara arrived with the first Maori settlers a thousand or more years ago. Great roasted,baked or boiled and recently we’ve started making chips with it!

  67. this is great! I’ve always wondered what the true difference was between yams and sweet potatoes. I’m learning to like sweet potatoes again as when I was little I got sick off of mashed ones, and haven’t been able to stomache them until recently. I have a sweet potato at home that I’ve been wondering what to do with, and I found some great ideas here! Thanks!

  68. I have been making some yummy muffins with them…

    3 Egg Whites+ 1 egg, 1/4 Cup Pumpkin, Pumpkin Pie Seasoning to taste, 1/4 cup almond meal, 3-4 oz Yam with skin (Pre-baked or microwave to super soft texture), 1 tsp Vanilla, Cinnamon to Taste, 1/2 tsp Baking Powder, 1/3 cup cottage cheese (or ricotta cheese).

    Pre-heat oven to 350 degrees. Blend all the ingredients together until batter forms. Spend a little extra attention on making sure the skins of the yam are broken up a bit, or place everything in a food processor. Spoon into a pre-lined cupcake pan. Bake @ 350 for 18 – 22 minutes.

    1. copied this one in a flash…good idea also for pumpkin use this time of year! thanks vicki

  69. Until my kidney stone a few months ago, sweet potatoes and beets were my main source of carbs outside of fruit. I am wondering if you have any clue as to what I can replace the sweet potatoes and beets with. There do not seem to be any root vegetables that are safe outside of white potatoes.

    My second problem is related: I live with a vegetarian and have gotten her to increase her quinoa and lentil intake so we can eat together, and we have been soaking them for 24 hours as Stephan Guyenet recommends. But unfortunately most plant based protein sources are also pretty high in oxalate and am wondering if anyone knows of any that are not. I don’t want to always have separate meals from her, but maybe our protein sources will have to be.

    thanks

  70. I don’t see any mention of lectins, saponins or other auto-immune offenders that classic potatoes have. By omission, does this mean that they are safe for moderate consumption by we that suffer any auto-immune issues?

  71. The only time I use yams is to make croutons! I dice a yam into small cubes, cook them over medium heat in unsalted butter with a little red pepper (a lot if you prefery), salt and fresh black pepper. I stir occasionally until softened, about 15 mins. Then I turn up the heat until diced potatoes are golden brown, 5-7 minutes. They are crisp and crunchy! I then stir in finely chopped fresh flat-leafed parsley. I use croutons in salads and on soups and they are delicious!

  72. Eggplants are different in Italy and Asia than in the US. Rutabegas and turnips are often confused in the US. In Scotland they are called neeps. Diced rutabega served buttered is as good as any vegetable, IMHO.

    HB

  73. This takes me back to the time I lived in Japan from 59-64. We lived in Kichijoji on the outsiirts of
    Tokyo. I would wait for the man to come by with his cart and the call of “Yaki Imo” and go out an purchase a sweet potato for ten yen (360 yen to the dollar then). Wrapped in newspaper, good eating.

  74. So let me get this straight: paleolithic man’s diet consisted of significant amounts of dug up tubers but not of cereals plucked from grasses? And also, we are to believe that the fructose in potatoes is harmless. Right, got it.

  75. In Europe we have the Vitelotte http://en.wikipedia.org/wiki/Vitelotte
    also goes under the names Négresse, Zwarte Truffelaardappel or Truffe de Chine.
    They are originally Peruvian potatoes.

    Not sure if this is the one you where referring to as the not ‘true Okinawan sweet potato’

    It is very poplar for making crisps and is sold as a ‘healthier’ type potato.

  76. VERY comprehensive!
    I do need to say that I’ concerned with invasive species that threaten the existence of our own native flora and fauna. The consequences of this are not being taken seriously by the government, that is clear.

  77. I found some Okinawan sweet potatoes at a Vietnamese market last night…but the sign described them as “purple yams” LOL!

  78. Every thanksgiving I make a mashed sweet potato with chipoltles and maple syrup topped with pecans. yum.

  79. i do love sweet potatoes. I cook them multiple ways. my fav would be to cook them like you would mashed regular potatoes but when it comes to mashing them i mash them with a squeeze of honey, a grate of nutmeg, the zest and juice of a lemon and a lil s&p… fantastic!!

  80. I LOVE sweet potatoes!!! I eat them every week when they are in season at the farmers market and then buy them over the winter as one of my cheap and staple vegetables. My favorite way to eat them is baked in the oven until they are squishy and sweet syrup is running out of them. Yum!

  81. I’d like to hear some more details on ur process of growing ur own sweet potatoes. Will they do good in So Cal? When should they go into the ground and how long do they take to become ripe? I would love to add them to my personal garden. Any info would be helpful.

  82. Hmmm, I’m gonna hafta look more into those Okinawan purple sweet potatoes. Thanks Mark for this daily apple.

  83. Just had a Yukon Gold, an Okinawan purple sweet potato, and a Japanese sweet potato. The diversity of the colors is absolutely amazing. The diversity of the taste – just as impressive! Talk about Thanksgiving…it’s only 10 AM over here, and it’s already absolutely fantastic. That so much variety and enjoyment should exist in the food we eat really is an incredible thing in and of itself.

    I find that the Yukon Gold is a good “palette cleanser” for the Japanese sweet potato. I found it almost sickeningly sweet too — very good, but a little too much for me. Alternating bites of that with the Yukon Gold really made it a whole lot better.

    Also, thanks for this post, Mark…great reference. And since discovering purple sweet potatoes I’ve found a new passion in life XD

  84. What about “Black Potatoes”?

    I know purple foods generally have antioxidants/anthocyanins, but haven’t seen anything regarding black.

  85. I love my sweet potatoes. I make ’em 3 ways:
    1. Slice & dice, season, and slow cook them in a wok with a little bit of olive oil.
    2. Mash ’em. A drop of milk, a bit of butter, and onion salt and i have one of my favorite complements to pork chops seasoned with marjoram.
    3. Boil ’em in the microwave. Scrub the skins but leave them wet, poke some holes in them with a fork, put them in a plastic shopping bag and tie the handles. Microwave on high for 5 minutes. (I learned this tip from my Auntie in Ireland)

    1. taro is my favorite tuber, too!

      (i like the the big one better not the small ones)

  86. My favorite way to cook sweet potato which my whole family loves. I chopped the washed sweet potato into small cubes (skin and all). I saute them in coconut oil with some chopped vidalia or sweet onion until they are soft and browned. Sort of like sweet potato homefries. The coconut oil is key…

  87. I’m late to this post, FANTASTIC information. Thank you for sharing.

    The thing to do with Japanese Sweet Potatoes (Satsumaimo): Cut them into fries, toss with your oil of choice, and bake into fries. (Salt optional).
    They hold their shape much better than orange fleshed and the sweetness is perfect – not overwhelming like they are when you bake them whole.

  88. I always leave the skins on. Sweet potatoes make great wedges smeared with fat and sprinkled with Slap ya Mama seasoning then baked on 200 degrees C for 40 mins turning every 10 mins. We love ’em.

  89. Hi Mark,

    Great post! I frequently have to explain the yam/sw potato terminology to my cooking students. I love sweet potatoes and yams and they’ve been a staple in my diet for more than 20 years. I’ve never seen the purple sweet potatoes. I will not start hunting for them!;-)

    Btw: I find that sweet potatoes and yams with a smaller diameter tend to have a better texture and flavor than ones that are fat around the middle. I tell my students they should be firm, smooth, unblemished, and not any bigger around than a a circle you make with your thumb and fingers.

    Baking definitely makes them sweeter and more flavorful than boiling or steaming. Mashed (orange sweet potatoes) with lime juice (about 6 medium sweet potatoes + juice of 1/2 lime) makes an amazing side dish with butter, coconut oil, or macadamia nut butter on top at the table.

    Happy dining,
    Rachel

  90. Paleo and primal eaters who want to get more sweet potatoes into their diets can replace mashed banana with baked, peeled, mashed sweet potato or “yam”in baked goods. So, where you see paleo almond flour or coconut flour banana bread, muffin, or pudding recipes, you can use these instead.

    There’s research showing that sweet potatoes help control and lower A1C levels in diabetics.

  91. Sweet potato greens can be cooked just like chard, and the stems are good too! No need to boil first. I prefer them to chard. Yum. I’m in Austin, TX and we have these growing right now locally in August.

  92. There’s a restaurant here in Boulder called the West End Tavern. They serve sweet potato chips with a huge bowl of guac. My absolute favorite way to eat sweet potatoes these days. We also substitute sweet potato chips or fries for tortilla chips when we want nachos. Amazing! Since we’re still trying to lose weight, these are only an occasional indulgence.

  93. I am faily new to Marks daily apple, and i have noticed that several times that Mark and many of his followers,keep commenting on cooking foods in a microwave oven,including this newsletter on yams/sweet potatoes.
    Mark,surely with your views on healthy
    eating, you would be aware that microwave cooking is very dangerous,and could lead to various ailments, including cancer, I would urge everyone to throw away their microwave ovens.
    Bryan Barreto, Nottingham, England.

  94. Kia Ora from New Zealand. We have about seven varieties of sweet potatoe in New Zealand. There’re actually about 1600 varieties in South America. There are also about 4000 varieties of potatoe. Their culture evolves around these vegetables. I mention this because research here might render many diverse and healthful sweet potatoe recipes not too mention medicinal uses as is the case with New Zealand Maori. The sweet potatoe can also be eaten raw. While I hadn’t seen all varieties eaten as such, I have seen the Japanese sweet potatoe eaten raw in New Zealand. Enjoyed the posts – Thank you.

  95. I’m 15 years old, although I’m not overweight, I definitely want to lean up (: Anyway, my favorite ‘sweet potato’ would have to be the Okinawan potato – it’s so good. I eat more than I should though, I used to eat one a day, but i think I’ll cut back to half a potato after my workouts. I’m taking the 30 Day Primal Challenge so, best of luck to me & thank you so much for posting.

  96. I made some really good sweet potato chips once…sliced thin with a mandolin and fried in grass fed beef tallow…seasoned with Cajun seasoning.

  97. I use them in hash — fry up some chopped bacon w/ onions, cut the yam into bite size pieces and toss in the bacon/onion mix. I also throw in last night’s leftover meat (pork loin cut into chunks, roast chicken, whatever). Add a bit of apple pie spice (cinnamon, nutmeg, allspice), some sea salt & pepper and it’s an awesome, delicate blend of sweet and savory. You can do the same with apples in place of the yams.

  98. The wife and I STILL don’t understand why it’s ok to eat sweet potatoes, but regular spuds are not cool. I just have faith and accept this, but my wife raves about them being basically the same thing. How do I persuade here?

    1. “Regular spuds” are in the nightshade family while sweet potatoes and yams are in the morning glory family.

  99. I have been told that our U.S. sweet potatoes are sweeter than yams, correct? Also, as a breast cancer survivor, I avoid these because I’ve been told they are estrogen-producing in our bodies? Correct?
    I’ve been told that one is a member of the nightshade family…which one?
    Thanks!

  100. hi mark, just reading this article from the link on your weekend link post from nov. 20th, the sweet potato leaves are called ??? or literally, sweet potato leaves in chinese and you should be able to get them in most chinese stores in LA. monterey park is full of them. they are great as a quick stir fry.

  101. Are ALL of them about 22 grams of carbs and 3 grams of fiber for a small one? Or do they vary. Which are the lowest carb ones?

    BTW, I grew up on Okinawa. We used to eat “on the economy” (off the military bases in local restaurants) but as far as I recall, I NEVER saw a purple sweet potato, ever.

  102. Thanks so much for the info, you certainly did your homework. Glad to know what that we cleared up the confusion between yams and sweet potatoes.

  103. in the uk the ones listed as ‘the yams’ are standard sweet potatoes. i cut them into 1 inch chunks, roast them til theyve got some colour,caramalised a little then mash with butter and full fat milk. roasting helps remove the water so the mash is thicker and the caramelisation adds much more flavour. i also slice them about 1 cm thick, put them in a pan slightly over lapping so the whole pan is covered by a single layer and covered half to three quarters with stock,4 tablespoons olive oil , a few bashed garlic cloves, fresh rosemary sprigs and thyme, put the lid on and steam until cooked. try this 2nd method with white potatoes also. serve with grilled (or broiled if you’re in the US) lamb or pork chops marinated in more garlic, olive oil and rosemary. add the lamb/pork fat into any left over stock from the potatoes for a nice gravy. yum yum pigs (or lambs) bum.

  104. Okinawan sweet potato IS so delicious. Just picked up a box from Costco here in Hawaii 🙂

    Didn’t realize they had more antioxidants as blueberries. Good to know!

  105. Could someone please comment on eating the skins of sweet potatoes? I always do that but this article made mention of anti-nutrients, without further explanation. What exactly makes it dangerous to eat the skins?

  106. Mark, interested to hear your thoughts on the post-workout eating window.

    I’ve heard 20 minutes, 1 hour, 2 hours.

    Also worth noting, I get home after a lifting workout, eat and then go to bed shortly afterward. Last night, I had a yam with unsalted organic butter and six strips of bacon. The idea keeps nagging me that it’s bad for me to eat, then be in bed about 30 minutes later.

    Thoughts?

  107. I suggest removing the skin before eating. I think the skins are irritating to the digestive system. Sometimes they actually taste moldy or just funky. Anti nutrients interfere w/nutrient absorption. Many are bitter tasting too.

  108. For fantastic flavor, choose sweet potatoes and American “yams” that you can wrap your fingers around. Wider ones tend to be tough and fibrous. Rinse, scrub, place on a dry baking sheet (no foil, no oil, no water). Bake at 400 degrees F for about 1 hour or until squishy soft, turning them over after 30 minutes to caramelize both sides.

    Remove skin, mash with a little raw butter or coconut oil, add juice from finely grated, squeezed fresh ginger root; squeeze of lime juice is also good. Really delish! (for more recipes and amounts see my paleo book, The Garden of Eating)

  109. My local store doesn’t know the difference either.
    Here’s something I found interesting on
    inflammationfactor.com/look-up-if-ratings
    Sweet Potatoes have a really high anti-inflammatory rating and Potatoes have a really low rating.
    She doesn’t list yams.

  110. Thank you for the recipe on cooking the yam leaves, I grow the orange yams, and they are very delicious, cooked any way! Will now try cooking the leaves.

  111. I cook the orange yam called Jewel, or beauregard, I love them any way you cook them. I grow them in my garden. I will now try cooking the leaves, as per the the person who was in the peace corps, and will saute in butter, as I am not fond of coconut oil.

  112. Those Japanese sweet potatoes are the only ones available down in costa rica where I live. But they are delicious roasted with olive oil and spices and dipped in Dijon!

  113. Thank you for such a informative and great article. I have noticed that some of my Tongan (South Pacific Island/Polynesia) language derives from Spanish just like the word Kumar is Kumala. We have a limited alphabet and replace r with l, j with s, and most words end in a vowel a, e, i, o, u but never y since it’s not in our alphabet.

  114. I had Okinawan sweet potatoes when I was in Maui last year. They were absolutely one of the best things I have ever tasted! I wish they were readily available here – I live in the middle of nowhere, so my selection of “exotic” foods is pretty depressing. 🙁

  115. Back home in Ethiopia we just cook sweet potato in plenty of water and after cooked you peel the skin and eat it. mostly used as a snack as TEff injera is the main food. Do you guys know what TEFFis? another great food which should be introduced to the world as great food,

  116. Thanks for a great article on the differences between sweet potatoes and yams. the thing that I’m having the hardest time finding out is the nutritional info on the “yam” Are the carbs the same as the sweet potato or do they fall under the yam nutrition profile. I buy the deep orange with the reddy brown outside and always thought it was a true yam. Now I’m confused!

  117. Peel them, boil them, mash them with butter, some sea salt and some yogurt or milk – them I put them on top of a 4 egg omelet and eat it with some sauerkraut and mustard – sometimes I put some sardines on as well

    1. i actually mix a little sauerkraut and juice with my mashed sweet potatoe, and a sprinkle of hempseeds. i love sweet and sour……..yummy.

  118. I love the Portuguese yams (inhames). I boil them whole, then slice them into about 1/4 inch slices and fry them in olive oil, garlic, and crushed red pepper (not the dry flakes from the spice dept). Unbelievably good. There are Portuguese markets in southeastern Massachusetts that have them, about an hour and a half drive from where I live, I’m not sure where to get them elsewhere though.

  119. Do yams belong to the nightshade family? I heard nightshade foods can be toxic to certain sensitive people.

  120. I use them in everything but as sitting here right now.. I made myself a creamed yam soup with some cheese.. omgs yummy.

  121. Well, finally an answer to my question “what is the difference between a yam and a sweet potato?” I guess I’ll just order sweet potatoes now. Thanks for your very informative data.

  122. I was recently gifted a large bag of sweet potato greens & was extremely delighted with them both raw & cooked. They are very mild, slightly sweet & have a spongy texture that made a soft delicate addition to salad. When added to my chili they soaked up & enhanced all the flavors without wilting & losing that amazing texture.

  123. Thanks for this article Mark! It has clarifies a lot. Me and my family have had a debate for years over what a sweet potato and yam are. Im excited to check out the local asian markets to find some Okinawan purple sweet potatoes!

  124. I love sweet potatoes and yams especially. I never knew there were so many other kind of different potatoes! Do you have idea what kind of potatoes are used mainly in making normal potato chips?

  125. i bought two real yams from a african grocery stand but only tried one kind so far, and it tasted exceedly bitter , did i do something wrong or is it suppose to be this bitter, i thought yams are sweet

  126. Very interesting post! I do quite a lot of cross fit and so far was using fruits (massive amount of fruits) as my sole source of carb…So I’ll definitely start using yams in my diet.

    My question is: Why are yams or sweet potatoes considered primal but not standard potatoes?

    What is the scientific reason behind it? Nutritional content is different? Or is it simply a question of history and domestication?

    Thanks,

    Max

  127. Whoa what an awesome article! I’m Japanese-American and I grew up eating all of those bad boys. The Japanese mountain yam (we call it tororo) is often ground up much like we grind fresh ginger. It becomes gooey and we pour a little soy sauce on this (or coconut aminos or tamari) and eat it with raw tuna and a raw quail egg (yamakake) and its heavenly. But beware, it will make your hands itch if you touch it so prepare with gloves!

    Also those purple Asian potatoes can be turned into flour and thus into baked goods. I know many in the primal/paleo communities want to avoid those carbs but I’m also a mom and giving my kids purple pancakes full of nutrients and the carbs their little active bodies need works wonders. Making asian style sandwiches on the go with the leftover pancakes with pickled veggies and some pork is also pretty amazing.

  128. My understanding is that standard sweet potatoes are extremely high in oxalates, not just the Japanese kind. Adding calcium citrate powder to mashed sweet potatoes adds some credence to this, as the texture gets gritty (presumably from calcium oxalate crystals). Shouldn’t people with hypercalciuria and kidney-stone formers avoid them, along with spinach and other high oxalate foods?

  129. I came across the ‘Perfect Health Diet’ which is a basic paleo type diet that advocates potatoes, sweet potatoes and white rice as “safe Starches” and that they can be included daily – mashed with a bit of apple cider vinegar and butter.

    I proceeded to do this in modest amounts each day and 3 weeks later found myself 3.5 kg heavier! They did say this could happen initially but I’m wondering how long ‘initially’ lasts for.

    I can see that your article suggests only yams/sweet potatoes and now and then.

    Is the PHD incorrect or could I just be intolerance (I am fructose intolerant according to a breath type test I had).

  130. Thank you for the sweet potato & yam info. I was in a store in Houston, confused by the sweet potato & yam labeling. Actually, I think of the orange-inside kind when I hear “sweet potato”, but I wanted the healthiest potato. Thanks to your breakdown, I ended up picking the okinawan variety. 🙂

  131. You can get some nice sweet potato leaves by sticking toothpicks in a piece of sweet potato and rooting it in a glass or jar (toothpicks keep it from falling in). We did this with our children when they were young. It is sort of a nice component to an “apartment farm”.

  132. i would like to know why japanese sweet potato is much sweeter than ordinary sweet potato. besides it has some sort of sugar liquid after cooking it, is that natural sugar content or there are rumours which state that the farmers grow them by watering with sugar water ? thank you

  133. I actually find the pale sweet potato tastier and sweeter in a nice way than the orange-flesh ones so when I’m cooking just for myself I’m reluctant to turn on the oven just for a small amount of food. I scrub the skins under running water and then steam them whole on the stovetop until they are quite tender. I find that I prefer to eat them plain b/c even butter or cinnamon, to me, interferes with the incredible natural flavor of the potato itself. So I just wait for them to cool enough and cut them into sections and boy oh boy are they great! I’m on the thin side so I don’t worry about calories, plus I find that I always feel so good after eating them, as long as I don’t binge, which I could easily be tempted to do! From your description of the Okinawan Purple I am in search of it… NOW! Thanks also, Mark, for clearing up the differences among the different types.

  134. My nutrition professor told me that yams and sweet potatoes aren’t considered a starch because of their red/orange color. I’m so glad to be getting a quality education.

  135. I start everyday with my version of Marks Big Ass Salad. In a skillet, a grill up some grated sweet potato (type varied based on availability) using some olive, hemp and walnut oil, occasionally some ghee. Then 2-4 eggs over mediumish. Add that on top of the salad. Salad consists of every and the kitchen sink, raw. Kale, chard, collard greens, fennel, beets and their shoots, mushrooms (oyster, crimini, domestic), radishes and their leaves, misc carrots, red or yellow onion, red cabbage, celery, diced tumeric and/or ginger, diced apple or other fruits, handful of nuts and seeds (sunflower, pumpkin, hazel, almonds, Brazil, etc), apple cider vinegar, unheated oils, pink Himalayan salt, kelp granules for iodine, fresh squeezed lemon or lime juice, minced or chopped garlic and I carry it around in a big ass bowl to serve as my breakfast and lunch. My bowl is custom, handmaded pottery with the label “chow”. The sweet potato makes the whole meal what it is. Its a must! Oh, and not all ingredients r used every time as it just depends on what I have and I only shop at our local co op so almost all is local and organic.

  136. Something to think about. If you have any room in your yard, and you like gardening at all, grow your own! They’re very easy to grow. Very forgiving, like other tubers. Purchase the ones you like, let the eyes sprout, and then plant them and wait for a tasty reward.

  137. In the Philippines sweet potato leaves are generally cooked in most beef stew dishes the leaves impart a very interesting flavor

  138. Awesome Post! I am a big sweet potato lover as I noticed it helped me with my Adrenal Fatigue considerabely. For a long time I have been eating, or atleast I thought I was, the purple sweet potato but I have become confused if it isn’t actually a yam instead.

    One the box it says it are sweet potatoes grown in America/South America (somtimes africa or Asia) but from the outside they look quite different from the Okinawan version. Maybe you could help me identify what they are exactly!

    They look like this:
    http://i.imgur.com/Te0sXkq.jpg

    ps. sadly It is nigh impossible to actually buy Okinawan or Japanese sweet potatoes in Holland. Can you buy them instore in the USA ?

  139. The Japanese “Mountain Yam” (Nagaimo) is phenomenal in a clear broth chicken soup. Browned dark meat chicken, chicken stock, ginger, nagaimo skinned and sliced; carrot slices — simmer for 20-30 minutes or so. The add enoki mushrooms and just heat them through. Delicious. Note that it thickens things a bit, but the thickening come from proteins in the yam, not starch!

  140. FYI the picture you put for “Okinawan Purple Sweet Potato” seems to be a Okinawan purple yam. I have never heard of Okinawan Purple Sweet Potato, but I had Japanese Purple Sweet Potato before, which looks not at all similar to your picture.

    BTW purple yams are much better than purple sweet potatoes. Some Cantonese merchant use taro and purple sweet potato mixture as an imposter of purple yam when making their food.

  141. Being born in Southeast Asia where both are purple yams and sweet potatoes are common (and NEVER confused with each other), I have to honestly say I prefer purple yams by a very large margin to sweet potatoes.

    We call purple yams “ube” and it has one defining characteristic aside from its attractive purpleness – its fragrance. The best comparison is pandan leaves, which is also used to add fragrance (and thus flavor) to food. To those also unfamiliar with pandan, the best way I can describe it is like a light vanilla with hints of lilac and coconut.

    Sweet potatoes don’t have this.Mix Okinawan sweet potatoes with another dish and you won’t even notice its there. It’s just another sweet starchy paste.

    Ube, however, You will definitely know its there. And yes, McCormick actually sells ube extracts. Which should give you an idea of how important its smell is.

  142. I was looking for a difference in sweet potatoes and yams in terms of nutrition on google and this page popped up and wasted my time.

    Very unorganized post.
    It needs to be reformatted to have basic useful information at the top and all the history behind it all the way to the bottom.

    Hope my criticism is taken constructively.

  143. For a treat, I’ve baked sweet potatoes until about 2/3 done and then slice them and then panfry them in Kerry Gold butter (no salt). These are the bomb when you want to munch on something and the old sweet tooth is kicking in…

    These are not potato fries! Do NOT add salt! salt spoils the sweetness for me. You can add pumpkin spice if you want, or cinnamon, but it’s the heavenly odor of butter and sugar burning together that reminds me of cake baking in the oven…