Potatoes get a bad rap in many different health and diet communities. The keto and low-carb crowd says they’re too high in carbohydrates and will spike your blood sugar. The paleo guys are against them because they are neolithic foods from the New World that our Paleolithic ancestors had no access to. The autoimmune diet communities eschew them because they have various plant toxins that can cause inflammation and trigger sensitive and vulnerable individuals, and the conventional “healthy diet” people recommend against potatoes because they’re “empty white carbs.”
Is this criticism warranted? Is it true that potatoes have no place in a healthy diet, or are potatoes actually healthy? How do potatoes fit into a Primal diet?
Let’s dig into the actual evidence.
Potatoes are healthier than you think
Potatoes are actually healthier than you’ve been led to believe. Think about what a potato is: it’s a repository of nutrients for growing many new potatoes. It’s an egg. And just like eggs are among the most nutrient dense animal foods on earth, the basic potato is one of the most nutrient dense vegetable foods on earth. In a single large baked potato weighing about 10 ounces, plain, you get a broad assortment of vitamins, minerals, protein, and prebiotic fiber.
Potatoes are high in vitamins and minerals
Here’s the breakdown. Percentages refer to the proportion of the daily recommended intake for each nutrient.
16% of B1 (thiamine)
11% of B2 (riboflavin)
26% of B3 (niacin)
22% of B5 (pantothenic acid)
55% of B6 (pyridoxine)
21% of folate
32% of vitamin C
39% of copper
40% of iron
20% of magnesium
28% of manganese
34% of potassium
10% of zinc
6.6 grams of prebiotic fiber
7.5 grams of protein
All that for 278 calories and 56 grams of “net” carbs.
Potatoes are rich in potassium
Dietary potassium/sodium ratio is a crucial determinant of endothelial function and blood pressure regulation, most likely more important than sodium alone, and there’s decent evidence that potatoes are a great way to improve potassium status. Potassium from potatoes is as bioavailable as potassium from supplements.1 In fact, adding potatoes to the diet can be more effective at lowering blood pressure than adding an equivalent amount of straight potassium.2
Potatoes are higher in fiber and lower in carbs than you realize
Potatoes have the reputation for being a “refined carbohydrate” that “spikes” your blood sugar. They’re supposed to be very high in carbs. That’s true—potatoes are a rich source of starch. But the starch in potatoes is a little different than other starch sources. Going back to that figure up above, of the 56 grams of carbs in a large baked potato, 11 grams will be resistant starch—a prebiotic substrate that feeds your gut biome, produces butyric acid, and is not digested by your body into glucose.3 That resistant starch content goes even higher if you refrigerate your cooked potatoes.
In addition to resistant starch (which acts like prebiotic fiber), potatoes have a significant amount of fiber.
A recent study in type 2 diabetics compared the metabolic effects of an evening meal containing potatoes to an evening meal containing rice. Whether the potatoes were boiled, roasted, or boiled and then refrigerated before consumption, the potato meals elicited a more favorable effect on blood glucose than the rice meal in type 2 diabetes. Same number of calories, same macros (50 carb/30 fat/20 protein), the only difference was potato versus rice. Potatoes won handily, and in type 2 diabetics—the very population that isn’t supposed to be able to handle potatoes.4
However, potatoes only won compared to rice. Potatoes are still high in carbohydrates, and type 2 diabetics, people with insulin resistance, and anyone who has trouble handling carbs should exercise caution with potatoes.
Potatoes are very filling
A 1995 study testing the “satiety index”—a measurement of how filling a particular food is—found that boiled potatoes induced the most satiety of all the foods tested.5 Even if potatoes have too many carbs for your liking, they’re less likely than other foods to promote overeating—probably due to the water content, fiber content, and micronutrient density.
Note: plain potatoes are filling. If you throw a half stick of butter into your baked potato or sit down in front of a plate of French fries, they’re not so filling. You can eat far more carbs and calories from French fries that you can from boiled potatoes.
Potatoes have complete protein
While the absolute amount of protein in a potato isn’t very high compared to animal products, what protein it does contain is “complete protein.” That means it contains all the essential amino acids your body needs and cannot produce on its own. In fact, potato protein is probably the most complete plant form of protein.
Potatoes are low in plant toxins
Potatoes, being the reproductive organs of potato plants, have “passive” defenses against predators. They are stem tubers. They can’t run or bare teeth, so they chill underground to stay safe and employ toxic chemical defenders known as glycoalkaloids.
The glycoalkaloids most prevalent in potatoes are alpha-solanine and alpha-chocanine, which the plants use to repel pests. Most of the glycoalkaloids are luckily concentrated in the skin of the potato, forcing less refined pests to eat through the toxic stuff to get to the good stuff. This is probably why traditional potato-eating cultures peel the potatoes they eat. These days, the most common potatoes, like Russets, also tend to have the lowest amount of glycoalkaloids. This is no accident, instead being the product of generations of careful agricultural selection by farmers. Throughout history, then, humans have tended to avoid the bulk of potato glycoalkaloids, either unwittingly, by peeling potato skins, or by selecting the low-glycoalkaloid varieties that didn’t provoke stomachaches, digestive issues, or inflammation and sold well at the market.
But some glycoalkaloids remain. Are they harmful? High dose glycoalkaloids are clearly harmful, but most peeled normal potatoes do not contain high doses of glycoalkaloids. Most studies showing harm used supra-physiological doses of pure glycoalkaloids; one of the only studies to show harm using physiological doses that you’d normally get from eating potatoes used intestinally permeable rats with a genetic proclivity toward inflammatory bowel disease.6 This is a useful study, though, because it tells us that potatoes might be a danger for humans with leaky guts or existing inflammatory bowel disease.
To ensure you’re avoiding glycoalkaloids, always throw out or discard (or plant) potatoes that have begun to turn green or sprout. That signals an increase in glycoalkaloid content.
There are a couple older studies showing increased inflammation markers upon potato feeding, but one included wheat and other high-glycemic foods in the “potato group” (not just potatoes) and the other used potato chips.78 Was it the rancid seed oil the chips were fried in, or the potatoes? Was it the wheat bread or the potatoes? These tell us very little about the effects of whole, untarnished potatoes on inflammation.
But if you’re healthy with good gut health and function, I don’t think baked, boiled, or mashed potatoes will have a negative impact on your gut. In fact, the prebiotic effects of potato resistant starch and fiber may even have a beneficial effect on gut health.
Can you eat potatoes on keto?
Classic medical ketogenic diets force you to eliminate potatoes. They simply represent too large a bolus of carbs when your mental and physical health depends on you remaining in ketosis. If you’re more of a casual keto or low-carb dieter, there are instances where a potato can work.
Training: If you incur a “glycogen debt” through intense exercise, you can fill that debt using potatoes without inhibiting ketosis. Exercise up regulates insulin-independent glycogen repletion, so you don’t even need insulin to deposit the glucose into your muscles. High end athletes will often be in ketosis on a regular basis despite eating high carb diets, simply because they train so hard and so often.
Carb refeed: A carb refeed describes the use of intermittent high-carb, low-fat meals to “carb up” against a backdrop of low-carb dieting in order to boost leptin and increase energy expenditure. in many instances, this will kickstart weight loss and make your otherwise low-carb diet easier to stick to and more effective in the long run. If you’re going to do a carb refeed, potatoes are an excellent, nutrient-dense food to use.
Potatoes can be an effective short term weight loss “hack”
Way back in the day, people in the MDA forums and comment sections were doing “potato hacks” to lose weight. I’m no fan of hacks, but I have to admit that this one really does work for some people. How does it work?
For a period of 4-7 days, you eat nothing but potatoes.
Use vinegar, hot sauce, mustard, and other low-calorie, low-fat, low-carb sauces and condiments. Mayo and EVOO are off limits. Primal Kitchen ketchup and mustard are perfect.
Use minimal fat to heat or cook your potatoes. No more than a teaspoon of fat at each meal.
Eat until full.
Eat frequently. Whenever you’re hungry, eat potatoes until you’re not.
Keep exercising. This will minimize muscle loss.
Most people find they get tired of potatoes very quickly and end up losing 5-10 pounds over the course of the week. It becomes an exercise in trying to force oneself to eat as much as you can because the potato is so filling and you need to keep up your energy intake and nutrient status. 4-6 pounds of potatoes a day is pretty typical and provides ample levels of most nutrients (and even a decent amount of protein), but that’s hard to keep up. And therein lies the power of the potato hack: you simply can’t eat very many plain potatoes.
Even though I’m generally biased toward lower carb intakes—especially in overweight people with poor insulin sensitivity—I have to admit that if people ate potatoes instead of refined grains and other nutrient-deficient starchy carbohydrates, health would improve across the board. Potatoes are simply one of the safest, most nutrient-dense, and least toxic sources of carbohydrates available.
I hope this article helped you make sense of where potatoes belong in a healthy Primal diet. Take care, and let me know whether you like to eat potatoes or not!
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.