It is not how it works at all.

The fallacy here is that a human body is a machine with well-defined intake and output.

How would one even know what is "exactly" the right amount?

Over a year we consume 1 million calories. If one were just 0.1% off of systematically eating more (or less) than required then according to your model one would end up being 200 pounds fatter or 200 pounds leaner ... do you think that anyone can regulate up to 0.1% accuracy to what they actually need?

eating a little more or less has absolutely not discernible effect the body adapts to it.

0.1% of 1 million calories is 1000 calories, which corresponds to about 0.3 pounds. If someone gains or loses 10 pounds in a year, that means they were around 35000 calories away from equilibrium throughout the year, which is more like 3-5%.

So a 5% calorie deficit or surplus would have a fairly small effect during a single year, but over a decade or a lifetime the effect is huge.

oops, I sure got my digits wrong

It is exactly how it works, and you're taking "a small percentage" to a ridiculous degree to fallaciously disprove it. Try eating 10% more or less than what you need each day, not 0.1%.

Another question to pile onto this. Maybe you're the right one to ask.

I was always taught that the body uses up its glycogen stores before burning fat. But if that were true even a small calorie deficit would gradually use up our glycogen stores and we'd be walking around without any after that.

Plus before losing any fat you'd have to experience a glycogen crash/wall which most small deficit dieters don't experience.

Very roughly...

Generally what fuel your body burns depends on the intensity of work you are doing, so if you're walking you may be burning 80%+ fat, but if you're running a 10k you may be 80% glycogen.

However, if you eat too many carbs at a meal (beyond what you need in the next few hours), your body needs to get that excess out of your bloodstream, so it will do a combination of: - fill your muscle/liver glycogen stores (limited size) - burn any excess carbs in preferences to stored fat - convert any excess carbs to stored fat

Once it's got rid of the excess carbs from your bloodstream, it will return to burning whatever the normal ratio of fat:carbs is for you.

Consequently, if you always eat too much carbs, you'll gradually pile on the fat, unless you're doing large amounts of training which depletes your muscle/liver glycogen, e.g: elite athletes.

Actually, that IS how it works.

It may not be possible to know or calculate the exact intake and output values, but those values are not needed. Your body gives you cues.

> eating a little more or less has absolutely not discernible effect the body adapts to it.

Yes, the body adapts to it by storing or eliminating fat (among other things).

No, if that was true people would be always over or under the weight as it's impossible to know exactly how much calories the body consumes.

> Yes, the body adapts to it by storing or eliminating fat (among other things).

No, it compensates by changing your metabolic rate mostly. You eat less, you will feel more lethargic, you eat more and you will fill (and be) more active

1 billion*

2 - 2.5 million calories a day is normal for people with a normal level of physical activity.

In the US, we tend to use food calories, where 1 Calorie == 1 kilocalorie. The capitalization of Calorie is intended to show the difference in units, but in most written language, often isn't used.

You’re talking addition and subtraction, compounding deals with multiplication.

To reap the benefits of compound interest (in your favor), you need to stick to a plan. You can't dump your investment portfolio after 5 years. It's these small, daily decisions that add up over time. So while the output is multiplicative, the necessary input is only linear.

Yes but the linear input is not the relevant part. The compounding is.

If you had to put in compounding effort, the compounding output would seem far less intriguing or worthwhile. If investment returns weren't exponential, or required exponential input to receive exponential output, it'd be far less useful of a concept.

The word 'add' is overloaded for both mathematical and non-mathematical purposes.

Multiplication is just a specific form of addition operations and is easily writable as such.

But that's not compounding in the sense of compound interest.

Sure it is, if you think about how much harder it is to run at 225 pounds vs at 200 pounds.

Yeah, it's easier to run, but nah, because diminishing returns.

I am pretty sure that only applies to certain people. I stay fairly skinny no matter what, though I do move about a lot.

How old are you? My father was thin until he turned 27. He was never huge, but at 27 he was 170lbs (6'2") and at his peak, around age 65, he was a little over 200. He warned me about that. At 27, I was also 170 lbs (6'2") (I am nearly a clone of my dad), and then slowly gained weight. I briefly ballooned to 215 around age 31, but hammered that back down to 185, but since then it has slowly climbed to 200 (at age 60). I am back down to 196. In my early twenties I could eat a large 'special' pizza by myself in about 45 minutes. Metabolism changes with age. I dearly miss being able to eat anything I wanted at any time with no consequences.

When I was in my mid-20s I could also eat anything I wanted, and a big challenge for me was finding pants that were long enough (36” inseam) but also had a narrow enough waist. This was pre-internet, so the options were limited (I discovered early that Big & Tall stores required you to be both).

Fast-forward 20-ish years, and I’m still just as tall but I don’t have any problem finding pants that fit me. Sigh.

Start lifting :)

45 now.

Nonsense. Eat 4000 calories a day, every day, and lift heavy weights. You will quickly gain lots of weight.

Confirm. Went from 165 lbs running 55km races to 235 lbs with a 1,405 lbs powerlifting total in 5 years. I started this month to reverse the process, going to run a 50 miler next time this year.

So that would be close to double what I usually eat. I doubt I would find that easy, and it would probably involve lots of unhealthy crap.

I think the same applies principles apply as with bigger people saying they can't lose weight. You need to change your habits, and that is hard.

https://thefitness.wiki/faq/why-cant-i-gain-weight/

Adaptive thermogenesis says otherwise.