Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
21 May

Dear Mark: Leptin Resets, Cold Thermogenesis, and Safe Starches?

Before we get to the topics du jour I’d like to express my appreciation to everyone that participated in last week’s “Dear Readers” comment board. As I said, Mark’s Daily Apple, my books, and what I do is constantly informed by your thoughts and ideas. In other words, I couldn’t do this without you, so thank you for your feedback.

My team and I have compiled all of your ideas and have begun laying out a plan to give you what you want, and to reach the largest number of people possible. We’ll be checking things off the list in coming months, so stay tuned! Now on to today’s article…

From cruise ships to tweets to ice baths to supposedly hacked social media accounts, Dr. Jack Kruse the man is nothing if not controversial. But what about his ideas – do they have any merit? That’s what many of my readers have been wondering, along with how I feel about them. I’ve remained pretty silent on this matter, because Jack was doing his thing and apparently helping a lot of people in the process. I was doing mine and helping people in my own way. And all was well. Now, though, the questions are coming in droves, and I can’t really ignore them any longer.

“Do I have to sit in ice water to stay healthy?”

“Do I really have to eat 50 to 75 grams of protein for breakfast even if I can’t force it down?”

Etc., etc.

I’ve also included a question about safe starches for good measure. Ready? Let’s go:


What do you think about Jack Kruse’s Leptin Reset or his Cold Thermogenesis protocol? Any merit to them?


Well, let’s look at the Leptin Reset. What does it call for, exactly?

  • A big protein-rich breakfast, at least 50 grams’ worth, but even up to 75 grams.
  • Eat low carb Paleo, especially if you’re really overweight, in which case you should eat very low carb. Increase carbs only if weight loss progresses.
  • Don’t snack, especially late at night. Eat three solid meals.
  • Reduce or eliminate light exposure after sunset.
  • Keep workouts to a minimum, and if you do work out, do it after five.
  • Practice meditation or some other form of mindfulness before bed.

Sound familiar? Other than the emphasis on protein (more later) and the “after five” admonition, I can’t really find too much fault with this approach. It hits all the major points we talk about and have talked about in the past.

That said, my views slightly differ on the importance of protein in the diet. It can be extremely satiating, which is helpful when trying to lose weight and subconsciously curb food intake without obsessing over calories. Anytime you’re trying to stuff yourself with a macronutrient past the point of feeling disgusted with yourself, though, I have a problem. We shouldn’t be doing that. It shouldn’t be necessary. Studies do show that a high-protein breakfast improves weight loss and satiety better than a breakfast of any other macronutrient breakdown, but it should not be continued indefinitely.

I also question whether that amount of protein is really necessary – or even useful – for most people. Thirty grams at a sitting is probably the most your body can deal with. Of course, if you’re legitimately using that protein toward muscle building and repair, have at it. Metabolically healthy, training hard and lifting heavy? Eat to your heart’s content. But if you’re eating protein just to stuff yourself and stay full and satisfy a requirement you feel bound to, you’re going to waste a lot of it. As I’ve said before, I’m trying to minimize my use of glucose, whether exogenous or endogenously produced. If I’m eating so much protein that the excess is being converted to glucose, I’m not really minimizing it, am I?

What about the Cold Thermogenesis stuff?

I like the idea of using cold water as a hormetic stressor, and I even did a post on the benefits of cold water immersion back in 2008. Throughout the year, I take frequent cold plunges myself in my pool, which reaches the mid 50s in winter. I’ve been doing it for years now after a training buddy of mine turned me onto it. I use it for recovery after a training session, and sometimes just to wake up and feel energized in the middle of the day. My sessions typically last about five or ten minutes, but I’ve gone as long as thirty. What do I notice since doing cold plunges?

  • Enhanced recovery from particularly vigorous training or playing. I’m ready to go the next day, rather than feeling beat-up and worn down.
  • Reduced DOMS, even after a heavy day.
  • Less pseudo-arthritic pain in my lower body joints. My arthritis pretty much disappeared since going Primal and giving up endurance athletics, but once in awhile I’d still get a few lingering, worrisome pains. No more.

I’ve never had much fat to lose, so that’s never been a determining factor for me. I do have a concern, though, with the concept of regular prolonged immersions and cold “adaptation” for people trying to lose body fat. One of the epigenetic adaptations to regular long exposures to cold is an increase in subcutaneous fat, as the body attempts to prevent heat loss by building a layer of insulation (fat). This happens often in marathon swimmers who train in cold water. Even non-elite pool swimmers who put in huge yardage tend to have this layer. The other concern is what seems to be an increase in appetite after long exposures to cold (after burning all those calories shivering). That would seem counterproductive – and uncomfortable.

Dr. Kruse is enthusiastic, and, judging from his followers and his monster thread on my forum, many people have found success using his methods. I’ve got nothing against the man. I just want people reading his stuff to be cautious. Take cold plunges, absolutely, but be careful with the two-hour ice water baths. Be wary of some of the more fantastical claims, like improving your lifting numbers by 150 pounds just by sitting in an ice bath, getting “shredded” just from cold water exposure, or falling asleep in a bathtub full of ice for ten hours being safe.

If you’re really interested in cold water therapy, I’d look to Ray Cronise, the NASA scientist who helped Tim Ferriss on the cold water immersion section in the Four Hour Body book. He’s far more measured in his claims and recommendations. According to Cronise, “cool water” is very effective for weight loss, not just freezing cold water, and you don’t have to go numb for days on end to derive benefits from it. Another place to look for inspiration is Richard Nikoley of Free the Animal, who’s been experimenting with cold water exposure for a few years now. Check out Richard’s post from a few weeks’ back where Cronise participates; it’s pretty interesting. If you want to try this out without getting too obsessive or buying any special equipment, you could do the occasional cold shower thing, maybe, but my advice is to just go for a swim in a cool – or even cold – body of water. A pool, a river, a lake, the ocean, whatever. And yes, swim. Don’t sit and stew. Just do some laps, see how many times you can swim underwater from end to end without taking a breath, play Marco Polo, play water polo, get three more people in there for some chicken fights.

Hey Mark,

Safe starches. Are they really safe?


There are certainly safer starches. Things like white rice, yams, sweet potatoes, potatoes, and any other starchy root, tuber, or vegetable that are relatively free of food toxins (gluten and related proteins, grain and legume lectins, etc) are far better choices than pasta, bread, muffins, and pizza. But that’s not to say that everyone should be making those choices, day in, day out.

In general, I’m trying to burn as little glucose as possible. That’s not to say I’m always full-blown ketogenic. I tailor my carb intake to my activity level and my natural inclinations and desires. If I’m playing a lot of Ultimate or going through one of my periodical (but rare) two week stretches of heavy lifting and sprinting a ton, I’ll generally eat a few more sweet potatoes than usual and opt for nigiri over straight sashimi at the sushi spot. But that’s not very often. Most of the time, I stay active, but I don’t go nuts. I’m mostly burning fat, walking a lot, staying on my feet, maintaining a constant level of activity, and punctuating my days with brief spurts of intense activity. I’m not intent on increasing my work capacity, my muscle endurance, nor my ability to take a ton of pain and come out on top – even though I do pretty well when I try something (like Ultimate) that calls for that stuff. So I rarely feel the need to “carb-up.”

The common factor among all these scenarios is that I let my needs dictate my consumption. I call carbs “the elective macronutrient.”  If I need the safe starches to perform better at what I want to do, I’ll eat them. If delicious food that happens to be higher in carbs is in season, I’ll eat some. Just last week, I spied a flat of organic Gavota strawberries at peak ripeness on my way to pick up pastured eggs at the farmers’ market and felt like eating a bunch. So I did. I bought that flat and we went through it in a few days. Was it a “lot” of carbs? Sure, but they were delicious, the weather is really warming up, and they were in season. It just felt right. And because my glycogen stores are generally light, I’m sure I simply topped them off and then burned through most of it doing HIIT the next couple of days.

That’s how I think we should approach safe starches. If it feels right, if your body seems to want it, and you’re going to use those carbs, then go for it. If not, don’t. You’ll probably find that 150 grams of carbs gives a surprising amount of leeway. You’re still low-carb and relying on fat for the bulk of your energy needs, but you’re not in full blown ketosis all the time, which can be limiting (but useful as a therapeutic tool). And if it’s not enough, if you insist on hitting the training a little harder (than I’d like) some days, try a cyclic low-carb approach. Eat low-carb on rest days, higher-carb on training days. A “carb refeed” might be warranted in this case, and it would allow you to still be in fat-burning mode most of the time.

But ultimately, I think we should be focusing on becoming fat-burning beasts, running on clean plentiful fuel, enjoying steady even energy, and avoiding a lifetime of sugar-burning. If that means limiting the types of chronic high-intensity, high-volume training that necessitates eating loads of safe starches, so be it. That’s what I’ve chosen to do for the rest of my time here, and it seems to be working pretty well. I’m rarely ketotic, since I like my veggies and berries as much as anyone, but when I do slip into ketosis, it’s not a struggle and there are no side effects. The machinery is already in place and fully operational.

Well, that’s my take on it all. What’s yours?

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Mark, thanks for finally addressing the leptin issue that I emailed you about a few times.

    Sue wrote on May 21st, 2012
  2. Once again you prove to be the saner part of Paleo!

    PaleoDentist wrote on May 21st, 2012
  3. Aaah… cold immersion. I’ve tried, but I can’t even stand a cold shower for a few seconds. I also hibernate in winter. Not going to happen. u.u

    Audrey H wrote on May 22nd, 2012
  4. Doing the LeanGains routine and find eating carbs just doesn’t seem necessary. When I do I feel like, in the eight hours I have, it’s almost hard to get over 100 grams with all the protein and fats I get.

    Andrew wrote on May 22nd, 2012
  5. I hate wearing wet suits but its a must in freezing water!

    Steve wrote on May 22nd, 2012
  6. I dumped all grain even so called healthy whole grain, from my diet and I have never felt better, and people still cant believe that you do not need to eat grain to be healthy.

    skuafox wrote on May 22nd, 2012
  7. This conversation reminds me of an old (I think Japanese martial) tradition of alternating hot and cold water showers(dips). The point wasn’t to soak but to essentially ‘shock’ or task the body for tolerance sake – so you don’t get too comfortable. Just take your usual shower, then count to whatever, (5-10 worked for me) and swap to cold for the same count and switch back and forth about three or four times.

    I used to do this somewhat regularly and I always felt refreshed afterwards. Perfect for a wake me up in the morning or after a long workout/hard day.

    Perhaps longer stretches work for therapeutic or these ‘dietetic’ reasons, but I don’t see a reason for it myself unless there’s a medical issue/imbalance.

    Sid wrote on May 23rd, 2012
  8. You have no idea how long it took me to write this! Or even to drag myself into saying anything at all. But here:

    Leptin Reset: I have been carb addicted for more than half of my life, and have trouble giving them up on stressful days. I find that having a breakfast that is at least 30g of protein absolutely KILLS my carb cravings, and actually does have some impact on my appetite during the day.

    Cold Showers: Ugh! The only point of a shower is the HOT water! However, I will say that a cold RINSE after a hot shower leaves my skin and hair feeling cleaner, somehow, and I find I sleep better after it.

    Migraine story! I don’t know if there are people who might find this useful, but I get terrible, terrible migraines with aura — one of the worst ones came up a few days ago, and I had nothing on hand. I usually use an OTC painkiller that will knock me out for a couple of hours and try to sleep it off for a couple of hours somewhere warm. This time, I had no time for that and no OTC painkillers. What I DID have was pure coconut water. I drank it– and ended up with no headache after a few hours! Who knew, right?

    Dani wrote on May 25th, 2012
  9. Today The Doctors advised against cold plunges into water less than 70 degrees. They laid out some dangerous consequences.

    Sharra Moller wrote on May 29th, 2012
  10. Mark, thank you for covering this in a thoughtful and rational way. I have been reading some blogs, some for and some strenuously opposed to CT and leptin reset. All were quite opinionated without really having any studies or science to back it up. More like reading about an uncomfortable high school bitter rivalry. I also first heard of it in The 4 Hour Body.

    cnymicaa wrote on May 31st, 2012
  11. All this talk of cold showers made me think of two things:

    race horses get their legs rinsed with cold water post race.


    in Australia (at least where I was born and bred) the local government sent us out shower timers in the mail to make sure we have showers less than 4 mins long. My mother in law, and she’s not alone, keeps buckets in the shower cubicle and uses the water she catches for other things around the house.

    For a while there, it was forbidden to wash your car, even just the windows with a hose. You can only wash the car windows with a bucket of water.

    You cannot water the garden. Or the grass. You cannot run the outside hose at all.

    So all this talk of having 10 min showers made my mind boggle!


    Jane wrote on June 4th, 2012
  12. Some feedback on Dr Kruse:

    I followed his prinicples for 6 months (Feb 1 – Jul 31) EXACTLY without a single mouthful of cheating. Here’s what I found:

    1. Good physiological results in that energy and weight lifting improved
    2. Bad leptin srum levels. Levels, which were regularly tested previously, went through the roof and stayed there.

    I have a number of auto-immune diseases inc. MS and the re-current neck wobble got much better so yay!!

    I was interested in the rising serum leptin levels. I asked Dr Kruse about it but got his typical brush-off (when results to conform to his theory).

    I’ve never been much of a carb junkie and have been paleo-ish for about ten years. I’ve really struggled to maintain weight despite exercise and paleo and believe that LR is the problem.

    Interested if any of you might have a theory as to why my serum leptin levels went upupup!!

    Many thanks.

    claudia rowe wrote on August 17th, 2012
    • I think it comes down to self education. You do what works for you. Sometimes medication is required, sometimes it’s building a medical solution for yourself. Sometimes the answer is how to implement your medical research into your daily life and start to feel better.

      Unfortunately, Doctor’s are not trained to provide a total – WHOLE BODY network solution– how everything works together, to prevent and cure people.

      I read NIH, MAYO Clinic, City of Hope research, Marks Daily Apple, Dr. Jack Kruse blogs and realized each person is responsible for their own recovery, own health. Optimal health comes down to your knowledge about yourself and working with your doctors to find a solution for you. Doctors are only as educated about you as you are about yourself. Doctor’s do not provide cures.

      From a Wife of a Aplastic Anemia husband.

      T wrote on January 1st, 2013
  13. I asked Dr Kruse about it but got his typical brush-off (when results FAIL to conform to his theory).

    Woops, sorry about that.

    claudia rowe wrote on August 17th, 2012
  14. For the most part, do CT gradually over years.
    Step jump CT. My body is slightly different in that I fell ill with high temperature in Russia, survived, and oddly adapted to -20 degrees Celsius from what was comfortable of UK 12-16 degrees celsius. In T-shirt and shorts. Everthing worked fine, except when entering a warmer environment, felt either colder or much warmer. Outside temperatures and wind fine.
    Upon returning to humid tropics, I was constantly burning for about 7 years until recently. Reduced exercise, under trained, ate a lot more greens, coupled with Omega 3-6-9. Live with Ghurkas. Unfortunately, with humid tropics, illnesses creep back.

    PV wrote on November 16th, 2012
  15. I’ve been reading NIH studies, Marks Daily Apple Blog and Dr. Jack Kruse Blogs and it all comes down to each individuals age, medical situation, body type, life style, daily habits and food battles. There is no one-stop-shop that works for everyone. I have to read and look-up medical terms and acronyms to fully comprehend what I’m reading, but over all it’s enough information to tailor something for myself.

    I would have to say no-one-doctor or nutritionist has the answer or cure for being at our optimal health. The body is more complicated than opening a can of paint to change a room. The body is all linked, all dependent on something else functioning properly. If one thing is out-of-wack, sick, weak or broken there is physical out-ward signs of the imbalance.

    The MYTH is WEIGHT LOSS the truth is balance. The body needs a balance of Omega6 to Omega3, needs a balance of vitamins and minerals, needs a balance of idle time and movement, and it needs a balance based on an individuals age, medical situation, body type, life style, daily habits and food battles.

    Anything out-of-moderation is extreme and can cause damage. So for me the goal is personal, the obstacle is SUGAR, the out-come is to feel really good everyday, every time I eat and every time I wake-up.

    T wrote on January 1st, 2013
  16. My question is about the exercise and snacking I teach water aerobics and am in the water from 7-11am on Tues & thus and 9:30-12 and 1-2 on m-w-f. This totally contradicts the no exercise before 5 pm. My doctor has me eating breakfast, snack, lunch, snack, dinner since I am insulin resistant and wants to keep my blood sugars level. This too seams to be a contradiction. What am I supposed to do?

    Shannon wrote on March 1st, 2013
    • my email was wrong in the original post and I forgot to mention that I also make sure I have something available during the long hours in the pool in case I get hungry.

      Shannon wrote on March 1st, 2013
  17. I have finally dialed I in to the paleo pescatarian lifestyle. I eat 1 piece of salmon with skin every 3-4 hours. I coat with ginger, onion powder, cayenne, lemon juice, white pepper. I slowly cook on indoor grill next to me. I break of small pieces and chew very well. My salad is a small portion of cilantro, spring mix, sauerkraut, onion flakes, tblsp coconut oil, and chia seed too. I say too because it is important to keep the seeds thick not milk like in my e patience. Plus it tastes better. This is my main staple. I maintain ketosis very well. I found that if I limit workout to no more than 15-20 mins 2-3x day high intensity I can eat this and re over well and keep blood sugar levels very steady. I use a blood glucose meter to monitor be and urs-10 urine sticks mostly monitoring pH, blood, ketone, gravity. This visibility has really helped me eliminate many foods I thought were OK. Lemon juice and green juice can cause huge spikes if used alone. Using a small amount with meals is OK. Keeping myself in ketosis and suuplementing glutamine, ginko, b vitamins, acetyl l carnitine, c, ginseng, calcium and some others like NCAA and amino complex tabs really help. When I don’t supp amino I don’t recover as quick. Key is regulating how much since derived from dairy. No fruit no nuts no carbs or sugars. Only fats are fish, coconut oil, chia seeds, hemp, flax, some fish oils dha pills. Learning to reduce stress as much as possible in all daily activities makes a huge difference in hormone balance and adrenal health. Knowing when to explode like a lion takes extreme patience and having everything in balance.

    Rob wrote on April 28th, 2013
  18. Two quick points about the leptin reset. You’re right on, it shouldn’t be a long term diet, which is pointed out in the protocol. Also, the large amount of protein in the morning isn’t to keep satiated and lose weight, although that’s a benefit, it is to restore circadian rhythms. At least, that’s what JK says in the protocol.

    Mike wrote on October 9th, 2013
  19. I’ve had several weeks of the best (deepest + most consistent i.e. every night) sleep in years since starting the leptin reset (big chicken breast every breakfast along with bacon and eggs, far from stuffing myself i gulp it down), but this week I had two nights of bad sleep. As far as I can tell the only thing that changed was that I didn’t have much meat in my evening meal (just veg-and-bit-of-meat stir fry). It seems that to sleep well I need the protein before bed too. I am presuming this is temporary and the leptin reset temporary diet will correct my leptin levels (I have always had a huge apetite but have never been overweight) and then I won’t *need* all this protein to sleep well. Has anyone had similar experiences?

    (my exercise levels right now are moderate – plenty of move at a slow pace, a job where I stand a lot (teaching), and I surf or do lightish movnat 2-4 times a week)

    archaeologyboy wrote on October 19th, 2013

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