Hello Dr.F!
Is weight loss purely arithmetic (calorie in; calorie out) or is there a hormonal component? (does test. increase rate of fat loss; does cortisol increase fat retention, etc…)
Or are hormones simply involved in how they affect your eating patterns?
Is there more…
nuance?
Despite what your hormones are doing, weight loss only occurs in a calorie deficit.
As an aside, testosterone within the normal range doesn’t affect fat loss and cortisol doesn’t affect fat gain. Even those with hypothyroidism don’t typically gain significant amounts of fat.
I think most people overhype the influence of most commonly known hormones (e.g. cortisol, thyroid hormone, testosterone, insulin) on body weight, while ignoring the lesser-known hormones (e,g, ghrelin, leptin, PYY, the orexin subclass) that act at the level of the brain.
Exhibit A: me through teenage years up to my mid-twenties having 60kg at 1,81m despite having Hashimoto’s and therefore hypothyroidism and higher cortisol due to the autoimmune process. I started getting thyroid hormones sometime in my mid-teenage years but that’s still less than an ideal position.
For further reference I gained a bunch of weight (along with quite a bit of fat) using GOMAD, which was an absolute overkill of course. However, I reached 92,5kg at the time, then stayed between 85-90 in the recent years. I decided to go on a cut at 88kg this summer and now reached 78kg after some 4 or 5 months with some slight and simple adjustments to my diet (basically replacing low fat milk with cottage cheese, eating more veggies but less fruits and sweets in general and trying to concentrate my carb consumption around workouts).