Weight Loss and "Set Point" Theory

weight loss

Chuck Shunk


October 31, 2022

Weight loss problems

I have been trying to lose weight recently. My diet is a sort of a combination diet: mostly it’s caloric restriction heavily relying on pre-packaged meals to keep consistency. I also keep things pretty low-carb, and the pre-packaged meals tend to be heavily “keto” inspired.

Most importantly, I use a feedback-mechanism to keep on track. I weigh myself daily (first thing in the morning) and produce a daily graph of the trend of my weight compared with my weight loss goal, which is 1.5 pounds per week. If I see that my two week trend is below this goal, I’ll be more strict with my diet, whereas if I see the trend is below my target rate, I’ll supplement my diet with healthy snacks or the occasional treat.

Up until recently, I’ve normally had to supplement the regular diet in order to avoid losing weight too quickly. However, that changed recently . . . here is my most recent graph, with two particular time points highlighted:

The first period, from Oct. 22 to the 25th, saw me overeat on the 22nd in response to a lower than normal trend. This was an excessive adjustment, which I paid for with two days of strict adherence to the diet plus a little bit of extra caloric restriction. The weight came off rapidly enough.

The second period, from Oct. 27th to the 30th, saw me overeat just a little bit on the 27th in response to being too low again. This put me only slightly over target, but I went ahead and strictly adhered to the diet for the next two days.

The difference in diet between the two periods of restrictive eating was minimal. I try to exercise by vigorous walking on a regular basis and there was no significant difference in the amount of exercise between the two periods either.

Survival mode triggered

What was distinctly different in those two periods was how I felt. It was much, much harder to lose the 0.8 pounds from 274.2 to 273.4 than it was to lose the 5 pounds from 279.2 to 274.2. It’s been pretty rough: I feel lethargic and chilly; I’ve been experiencing some “brain fog” and a bit of shakiness. I’ve also been experiencing what I would call a “feeling of urgency” to eat more. It’s not hunger pains–a physical pain in the gut or a feeling of emptiness–so much as an irrational feeling of desperation.

Essentially, what I believe is happening is that I have crossed a certain threshold that my body has been tracking, and now it believes that I am starving and is taking steps to deal with the situation. The interesting thing is that I think this threshold is very persistent, because this is just about exactly the weight at which my dieting fell apart last year around this time as well.

I think this is evidence for what I believe has been called the “Fat Set Point” or the “Fat Thermostat” theory of weight loss. As I understand it, the idea is that your body keeps track of how much fat it considers “normal”, and once you have lost too much of this “normal” amount, it puts your body in survival mode, triggering strong hormonal urges to seek out food and turning off as much of the body’s metabolism as it can to preserve storage until more food can be found.

How to proceed?

If the “Set Point” theory is true, then it seems that I need to figure out how to convince my body that this is the new normal. How could I do that?

Well, I could just ignore my body and continue to diet, decreasing my intake all the more in order to keep on losing weight. This should work, theoretically, because there is only so much the body can do to turn down its metabolism in order to preserve caloric reserves.

However, the problem with this is the brain fog; one of the things that (apparently) the body can do to preserve energy is start denying it to the brain. But I like my brain. More to the point, I need my brain to continue at a pretty high level for my job.

So maybe what I can do instead is to level off . . . stop loosing weight for a while. Perhaps if I spend the next week or two just maintaining a consistent weight and not letting myself lose any, then that will give my body time to acclimate to the “new normal”. On this theory, my new “goal” graph will look like this:

I will be trying this for a week or two to see how it feels.