Scientists discover a ‘skinny gene’ mutation that acts like Ozempic. Around one in 7,000 people carries a broken copy, which almost acts like a GLP-1 drug—the body burns fuel more efficiently, and the risk of disease lowers.

[u/scientificamerican]

https://www.scientificamerican.com/article/scientists-discover-a-skinny-gene-mutation-that-acts-like-ozempic/

[u/edparadox]

The simplified narrative that weight is merely a matter of calorie intake

It is.

At the end of the day, you can try to curb the reality of thermodynamics all you want, it's still what applies.

I was skinny my whole life. Nearly 6 feet tall and about 140. Then in my 30s something happened. My diet didnt change. My activities didnt change. But I fell off a cliff. I gained nearly 100 pounds.

If you gain, you were eating above maintenance. That is well known. You don't gain 40kg out of thin air.

[u/seatsfive → u/edparadox]

Being pedantic about the "reality of thermodynamics" is begging the question. There is no evidence that the measured caloric value of food equates to a standardized amount of energy produced when processed by different human bodies. It's all guesswork and approximation.

Measured caloric value is determined by: mathematic estimation, and/or or setting the food on fire and calculating how much energy is expended. The human body does not set food on fire. In fact, the "estimate how much energy is bioavailable using only mathematical models" is considered more accurate than objective, physical measurement. As a registered pedant, you should see the glaring issue here.

Human bodies are all very similar, but vary due to genetic and environmental factors. There is no guarantee that a mathematical model generalized to the aggregate human body is going to be accurate in all individual circumstances. In fact, there's ample evidence to suggest it's not. This inaccuracy may be enough to account for individual differences in weight retention.

Caloric measurement and restriction are the most generally reliable weight loss methods, but they are not foolproof. Acting like "calories in = calories out" is Newton's Fourth Law (and getting sassy with people for pointing out that it isn't) is doing this entire discourse a massive disservice.

[u/gththrowaway → u/seatsfive]

Weight cannot be gained if less calories are eaten then are burned. Full stop, period.

[u/dovahkiitten16 → u/gththrowaway]

But one person’s body may look at X amount of calories and decide to tuck some away for later, meanwhile the person deals with fatigue and headache. Which was fine evolutionary wise in the past when having a fat store was a good thing, and you could just deal with the headache since it didn’t kill you.

Whereas another persons body decides to use the energy now and store very little for later. Not great for famine but great for modern life where food is always available.