So much for the reductionist and simplistic "calories in and out" trope brought up frequently on here.
CICO is neither a religion nor a complete explanation of metabolism. It’s a super simplified model that leads to some useful practical conslusions (eg it’s easier to eat less to lose weight than exercise more, some foods will make you more fat than others relative to how full they make you feel).
It’s super accessible, you can look up the calories of whatever you eat and whatever exercise you do.
I’ve seen lots of valid complaints about CICO, but never a suggestion for an alternative that’s similarly useful with even the same magnitude of simplicity.
Note I take CICO to mean bio-available calories roughly equals base metabolic rate plus exercise out for the average person. Actual energy-balance “draw a box around a person” joules in equals joules out is unhelpfully reductionist.
To me the issues comes down to how people deal with the simplicity: when we’re told we don’t have to think hard and focus on reading numbers on a label, it’s comforting enough to not want to get back to the cold hard truth. Even when it doesn’t work, it’s just simpler to blame people (including us) than to try to think hard again.
People hate disclaimers and caveats. You can provide as many disclaimers and caveats as you want with the ultra simple theory, they will be forgotten instantly, only the simple part will remain, evolve on its own and live its life as a meme.
I’m with you that it should be fine if it’s a net positive for the vast majority of people. But it’s now the prevalent advice, and looking the stats it doesn’t seem to have a positive effect. If anything, we now know the meme advice doesn’t work for most people.
If people don't or can't measure CI or CO then you can blame them for being wrong. All of this flies in the face of the fact that your body should be able to regulate this for you, which would make manual calorie counting in your head or via apps obsolete.
So there are only two possibilities left. Either our bodies are defective and we need crutches like machine assisted calorie counting or our bodies work just fine but there are some weaknesses that can be exploited and calorie counting is just a technique for defending against those who exploit them.
And no I don't mean there is an evil conspiracy by the food industry. Your obese parents telling you to eat two pizza per day can be equally exploitative because listening to parents' orders is higher priority than listening to what your body says about how many calories you have consumed.
How is one supposed to even approximate the energy balance without a fully body composition (dexa) scan every week?
I think we were referring to different sites of energy conversion.
think of it as a curriculum
Granted, this is me, a physicist, thinking simplistically. But it's what's always made me skeptical about metabolism.
There's really not much variation in metabolism. Most peoples' metabolisms are within ~10% of the average. [0]
Of course, even a very small variation adds up when compounded over years. 100 extra calories a day is a 10 pound weight gain per year.
But the variation itself is actually small. No one can "eat twice as much and not gain weight."
What doesn't work very well is "curing" fat people by just telling them to eat less. Yes it would work if they could just eat less, but it does not address their actual problem which is the compulsion to over eat. Might as well try to cure alcoholics by telling them not to drink. So I understand why over eaters get upset about it, it's not like they don't know they eat too much and they don't want to be so fat. Though advancing the conspiracy theory that food intake has little to no bearing on weight is not a helpful response to that either.
While that is a significant difference, I still think calorie counting gives a useful estimate, since people eat many foods and the error reduces in aggregate, as some are overestimated and others are underestimated.
In addition, people are not rabbits and may have evolved digestive systems better adapted to reheated fats since the invention of cooking (evidence of campfires 1-2 My ago).
That's how models work. They are simplified ideas to help people understand things. They're not intended to be an all encompassing theory of everything. Just like "supply and demand" works but breaks down in certain circumstances. In general "calories in, calories out" does work. The body may adapt, various foods affect you differently, but CICO is not a heretical idea.