January 12, 2020


My nutritional framework

Nutrition is such a loaded topic—almost a religious or political one—so I’m always looking for ways to explain it that are as free from that baggage as possible.

Read Time 2 minutes

I recently read a paper in The New England Journal of Medicine (NEJM): “Effects of Intermittent Fasting on Health, Aging, and Disease.” This review is one of the latest making the case that when you eat (and don’t eat) can have a profound impact on your health. But before looking into this study (we’ll do that next week), we need a framework to put it into context.

Nutrition is such a loaded topic—almost a religious or political one—so I’m always looking for ways to explain it that are as free from that baggage as possible. So far (and this is constantly evolving, so look for this to get better over time) the framework I use to explain eating is based on modifying three parameters or “pulling 3 levers” in various combinations. A few months ago I posted a short video explaining this way to think about nutrition. It comes down to three forms of restriction. Whether it’s what you eat or don’t eat (i.e., dietary restriction or DR), how much you eat (i.e., caloric restriction or CR), or when you eat and don’t eat (i.e., time restriction or TR), virtually all of the dietary schemes you can think of can be distilled into these three elements in some combination (Figure).

Figure. My nutritional framework.

Of the three levers, TR (often, though in my opinion misleadingly, called “intermittent fasting”) possibly contains the simplest dietary prescription: limit your eating to a window of X hours. For example, “Only eat between noon and 8 pm each day.” That’s it. Most people, out of the gate, are already doing something like a 10/14 TRF schedule, even without a modicum of effort (i.e., not eating for 10 hours; eating within a 14-hour window). From here, it’s pretty easy to get to 12/12 (e.g., only eat between 8 am and 8 pm). Then 14/10, and soon enough 16/8. Before you know it, you’ll be amazed by how easy 18/6 feels (e.g., only eat between 1 pm and 7 pm).  

I began experimenting with TRF in earnest in late 2013 and by the end of 2014, I had spent 6 months doing a 22/2 regimen every single day (which works out to basically one meal per day, grazed on over 2 hours). I’ll save the details of that for another time, but the metabolic flexibility I experienced was certainly on par with what I had experienced during my longer journey in nutritional ketosis. For example, though I was only eating one (large) meal per day at dinner, I worked up to doing a 6-hour very tough bike ride on nothing but water in the first half of the day.

Compare this to the thought, planning, and education—for the patient and/or provider—that goes into CR and DR with daily calorie-counting and question(s) around “Is it paleo / keto / vegan / sugar-free?” respectively.

One thing is for certain: if you want to be sick, don’t do any of these things. Eat as much as you want (no CR), of anything you want (no DR), whenever you want (no TR). This is called the “standard American diet.” The further you can get away from this pattern of eating, the better. As I say in the video, always pull one of the levers; often pull two; sometimes pull all three. 

Next week we’ll take a closer look at one of these levers, time restriction, and the recent review on it in the NEJM.

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    • CR- Calorie restriction
      TR – Time restriction
      DR – Diet(ary) restriction

      Was that your question?

    • Always be pulling one (1) lever; often pull two (2) levers; occasionally pull all three (3) levers.

      • I think Carballo meant to ask which one is 1, which one is 2, which one is 3. I still have the same question after looking at the image, reading the post and reading the comments. From the post, one might consider DR, CR and TR as 1, 2 and 3 respectively (from paragraph 2), but also CR, DR, TR as 1, 2 and 3 respectively (from paragraph 6). It is indeed not clear.

      • Wait… never mind! Mikal’s comment makes sense now. Pull any combination of 1, 2 or 3 items out of the three.

    • I can offer some advice here, as I have recovered from hypoglycemia. I recommend 3 meals a day and only eating when really hungry. Avoid sugar and refined carbohydrate. Eat enough protein and fat at each meal, to give a steady release of energy over several hours. If your blood sugar crashes 2 hours after eating, you are eating the wrong type of foods. Eat foods that digest slowly. Standard advice e to eat very 2 hours is a bandaid but bad for your long term health.

    • Great post!
      I’m sorry for nitpicking, and I know that axis orientation is relative, but the graph in this post appears to have the x and y in the wrong place (assuming standard orientation).

    • I actually noted the 2 min and timed myself. I read reeeally slooow. (you:cheetah, me:sloth). Perhaps my lag was due to digesting the framework of the 3 R’s…a new twist for me. As I think through it, it seems all 3 levers should be pulled all the time. The decision becomes one of how many notches in complexity do you want to pull each lever. Time is the simplest, quantity (the how much) and elements (the what) could ratchet up the notches of complexity as Peter mentioned. The QR and ER levers (taking some liberties) can be pulled at the #1 gear and not the #10 deep academic dive. Really liked
      “22/2 regimen every single day (which works out to basically one meal per day, grazed on over 2 hours)”

  1. Awesome article.

    In early 2019, I quit *all* sweet foods (deserts, fruits, juices, colas … the works), and after 2 weeks I cut out all snacking, eating only at mealtime. After 2 – 3 weeks of this, I found my transition to 16/8 TRF was absolutely painless. I believe that the sugar was triggering my appetite.

    Oddly, a month or so later, I started feeling that the act of planning and scheduling 2 meals a day was becoming burdensome, and transitioned to OMAD (one meal a day). This is pretty much the same 22/2 cycle Dr. Attia talks about. Periodically, I may change the feeding time (switching from breakfast to lunch), and go as long as 30 – 32 hours in fasting. On other occasions I switch around from lunch to breakfast; when this happens, the fasting gap drops to 14 or 16 hours, of course.

    In the course of the past year my weight has dropped from 127 kg to 112 kg. My activity level has remained unchanged in this time-frame, so I credit the entire weight loss to TRF. I was (and am) very overweight, so fitter individuals won’t likely experience such a dramatic fall off in weight.

    To summarize:
    DR = no added sugar / high sugar content foods (I still eat carbs – bread, rice potatoes – but not as much as before)
    TRF = predominantly 22/2
    CR = nothing planned, but I have experienced a marked down-regulation of my appetite.

    As Dr Attia likes to point out, [n=1], so YMMV 🙂

    • I think reducing complex carbs is a mistake. Obviously, you have to reduce simple carbs, but eating vegetables is the basis of the FMD, otherwise, it is impossible to inhibit mTOR.

  2. At the risk of being pedantic, I wonder if there is a fourth dimension around the mindset behind eating that enables better adherence to the main three levers. Maybe “how you eat”? For instance, being in a mindful, state so that your are getting more “bang for the buck” out of every bite. I’ve noticed that my mindset when approaching my meals has a high correlation with how well I adhere to each of the levers:

    1) CR – Eat less because I experience eat bite as more fulfilling and notice when I experience diminishing returns of pleasure for the next bit. This typically leads to me not going for seconds and being the garbage disposal that I’m naturally inclined to be
    2) TRF – More apt to gut through that last couple hours of my fasting window as I’m mindful of the benefits I’m forgoing if I do. Also related to lever 1, I genuine see the first meal as a reward for self-discipline and forgoing instant gratification
    3) What I eat – Have a more intuitive sense for making adjustments based on recent behaviors. For instance, ate processed food the night before with some carbs, so I’ll eat a more keto-friendly meal tonight.

    • @joey-m, I like this mindset. I am starting to use this myself.

      I only recently attempted a fast and went 41 hours very easily… even while having to prepare meals for my kids and my wife was slow-cooking some delicious food in a crockpot nearly the whole day. I could have gone 48 hours as well, but for some reason I felt like I should eat when I did because of my schedule.

      I also agree with Peter’s sentiment that intermittent fasting is pretty simple to both understand and follow. This makes it infinitely more easy to adhere to.

  3. You recently did a followup on this on Instagram, where you said that you’re currently “going all in on DR,” with no CR or TR, restricting only “all carbohydrates with the exception of vegetables and a couple of berries”, avocados, and nuts. You say you’re pulling “super-hard on this lever,” but you don’t say you’re on keto. Is that because you’re eating enough of even these low-carb foods that you still stay out of ketosis?

  4. My girlfriend has been a “light” anorexic for over 35 years: she is a full time school teacher, she stands 130 pounds on a 5″5 frame. She is, in my opinions a well balanced women, despite her addiction. My question is:

    What the heck is happening here?

  5. I wonder if there is a difference in how males react to the levers versus females. I also wonder if age does anything to change how the body reacts to the different levers. I am a middle aged woman with hypothyroidism and have struggled with fatigue and creeping weight gain (made worse because I am too exhausted to do the physical activities at the intensity I did in my younger years). I have tried pulling the various levers at various times in my life…sometimes in a vary disordered way. Most recently, I tried intermittent fasting and found that I had even less gas in the tank to be physically active. I am now trying to have more small (lower calorie) meals/snacks to see if that helps sustain better energy. I would love to hear Dr. Attia’s thoughts on if/how the levers might need to be thought of differently for men vs. women, young vs. old.

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