I stepped on the scale today and realized I had hit a milestone: I’ve lost fifty pounds since starting my weight loss efforts five months ago. It’s a nice, if somewhat bittersweet milestone to hit on this weight loss journey - I recorded a pretty similar milestone in 2018 while going from 275 lbs to 200 lbs. Life happened (happens, I guess) and while I’m a tad bitter, there’s some comfort in the confidence that I’m capable of reaching my goals when I put the effort in.

I wanted to write down a mental model that I’ve been experimenting with around dieting, eating habits, and weight loss. While this post is not a formally qualified opinion and does not constitute medical advice, it is largely inspired by ideas from Peter Attia and I think it’s a useful framework for me in understanding the many varied paths to the same goal.

Paths to a caloric deficit

Losing weight involves consuming less calories that you expend 1 over a significant amount of time and, especially among those with a lot of weight to lose, adjusting your eating habits is much more likely to drive success than exercise. All “diets” can broadly be grouped into putting effort along three levers: what you eat, when you eat, and how much you eat.

What you eat covers all kinds of food restrictions, including low carb (keto, Atkins etc), low fat, high protein, vegetarian/vegan, paleo, or otherwise. These primarily work because there’s a property about that food that makes it hard to overeat - in keto, you eat more fats and your brain thinks you’re satiated before you reach a certain calorie threshold, while in low fat and/or vegetarian diets you eat more greens and proteins so that your stomach becomes full before it can take in a certain number of calories etc. This works - the primary mechanism for me losing weight in 2018 was eating a keto diet and being ruthless about cutting out carbs.

When you eat covers all kinds of fasting - intermittent, extended, or otherwise. The primary mechanism here is eating fewer meals, so while you do eat to fullness you end up eating less calories than you would have if you’d eaten three meals. In practice your appetite is also somewhat diminished (or your stomach “shrinks”) so your fullness threshold happens more quickly and at a lower calorie threshold. This can also work on a broader scale as I’m doing right now in 2021, where over the course of a seven day week I fast on three days - effectively reducing my calorie intake by 40%.

How much you eat covers calorie, macro, or portion control for each meal. If this is the only lever you’re pulling, you’re doing the classic “track your calories at each meal” methodology and being precise about how much you take in at each meal - think of classic apps like My Fitness Pal, IIFYM etc.

All three of these levers, when properly applied2 within the goal of caloric deficit, do successfully lead to weight loss over time with adherence. If you pull none of them, you’re eating the Standard American Diet (SAD!).

Some levers are easier for some people to pull than others - the one that is easiest for me may not be the easiest for someone else. Heck, the one that’s easiest for me today (when to eat/fasting) is not the same as the one that worked the last time (what to eat/keto). In 2018, I ground out a keto strategy to some success, but found food boringly repetitive and socializing difficult. I’m finding fasting easier to stick to this time around, because when I do eat I don’t need to worry about “what” I’m eating or “how much” I’m eating at each meal - I can eat until I’m full when I do eat and eat whatever I’m craving.

You can pull these levers with varying degress of intensity (fasting for longer, reducing portion sizes more, cutting out more foods), and you can pull one, two, or three levers at a time. It is mentally draining to pull two or all three levers intensely at once - i.e. keto + one meal a day is very tough to stick to, as I’ve found out - it could be doable in the short term as a treatment but feels so unsustainable as a long term plan.

If you can strive to pull one of these levers at a time, you should be able to stick to that pattern for a longer period of time - and adherence to a caloric deficit leads to successful weight loss!


  1. There are some other hypotheses about why obesity exists, including the carbohydrate-insulin model, but I don’t personally find them very convincing after experimenting with them - more on that in another post, maybe. ↩︎

  2. All three levers have possible ways to fail at the goal of eating a caloric deficit - you can still indulge in too many calories while eating keto, you can binge eat when fasting so as to wipe out your efforts, and you can be poor/ineffective at tracking your calories at each meal (or misjudge the correct calorie numbers etc). ↩︎