[TrisMcC]

Do you really believe that the obesity epidemic was caused by people eating 90% carbohydrate diets?

The "high carb meals" at McDonald's, Burger King, Pizza Hut... are all also (and more per calorie) high in fat.

Add 2 tablespoons of olive oil to your mixed-green salad? That has turned into a high fat salad. Most people cannot avoid cheese or nuts on salad, either.

Eating the potato diet with sour cream/butter/cheese: High fat.

[devoutsalsa]

I'm overweight because I eat too much. Eat caloric surplus, gain weight. That part isn't complicated. Why I eat too much is another question...

[mrguyorama]

It's funny too, because I have perfectly logged data showing that the weeks I eat fewer than about 1800 calories reliably, (because I have an incredibly sedentary lifestyle) reliably and predictably lower my weight.

I've literally got a science experiment in my own body that shows reducing calories in, without reducing the actual design of my meals, reduces my body mass.

I'm willing to accept that there are some minor irregularities and difficulties that make "Calories in == Calories out" not 100% accurate, but I'm betting the effect size is closer to +-10%, and therefore easily discarded for approximations, even though they are scientifically significant and could create a more accurate model.

[bumby]

I agree that the CICO is a model that works, but it is at least somewhat complicated by the fact that CO is a function of CI. I.e., what you eat takes different amounts of energy to metabolize so it also contributes to what you burn. If I eat 1800 kcal of protein I may have higher CO than if I ate 1800 kcal of simple carbohydrates.

There's already a lot of uncertainty when most people measure their calories (very few people actually weigh their food) and this just adds another layer of uncertainty. I have a feeling those all combine to make it inaccurate enough in practice for some people to claim the CICO model doesn't work.

[goodpoint]

No. A healthy diet is a diet that provides you with the right amount of nutrients without leaving you hungry or unsatisfied.

By not being hungry and unsatisfied you'll then stop overeating (surprise!).

"My diet is OK, I just eat too much" is all wrong: there is a complex relation between caloric intake, which foods are eaten, hunger, satisfaction, energy, mood etc.

Many fad diets "work" even if they are not grounded in any scientific fact and are even unhealthy in the long term (low fat, low carb, keto, gluten-free, all-meat).

They artificially restrict the variety of food one person can eat and this indirectly encourages people to eat less. And when people stop overeating they feel better and believe the fad diet is sound.

There were even a diet where you can only eat foods in a given meal from the same group... by color. Same trick.

Bracing for all the downvotes...

[sph]

Talk about generalising. How is gluten-free unhealthy in the long term. Do you actually believe that wheat in particular is required for health?

Just above you said a diet needs to be nutritionally complete. Low carb, keto, gluten free, hell even low fat can be nutritionally complete and satisfying, though the latter one will not feel really good in the long term.

[devoutsalsa]

Your body stores calories you eat, and it's really good at it. If you eat too much of anything (that contains more calories than the calories required to digest it), you will gain weight. Eat too much fried chicken, gain weight. Eat too many oranges, gain weight. Eat too many beans, gain weight. You can probably gain weight from eating too much broccoli, although I'd get sick of broccoli before that happened.

[goodpoint]

Did you just repeated the previous point without understanding anything of what I wrote?

[devoutsalsa]

Calories surplus equals weight gain. Are you saying you disagree with that? Because it sounds like you don't believe that.

[goodpoint]

Try reading what I wrote instead.

[LesZedCB]

i thought fat was largely debunked as being the primary cause, though i'm not going to go searching for studies as i'm not a dietician (though my partner is).

consider this: each of those meals at McD's, BK, or Pizza hut come with a 1-2 liter soda, loaded with calories and sugar. yes, the fats are there, but they are _always_ paired with loads of sugar.

[seadan83]

I agree with the debunking that fats are not bad for you, though, not all fats are equal. The rule of thumb is that fats that remain liquid at body temperature can be considered "dietary fat". The only problem with "dietary fat" is they have a load of energy on them and that can blow your calorie budget for the day quite easily if you overdo them.

Fats though that stay solid at body temperature arguably should be completely avoided. Hence the big-mac with a 1-2 liter soda, loads of unhealthy fat paired with loads of sugar, all with very minimal fiber..

[emmanuel_1234]

I'd be curious to understand where you get that information from.

Fat that stays solid at room temperature is generally high in saturated fat (except for margarin, but let's keep it out). Fat that stays liquid is generally vegetable oil (e.g.: canola).

I don't think there is strong evidence that vegetable oil is good for you whereas saturated fat is not. If so, I'd really like to read about it.

[seadan83]

For fat vs sugar (ie: carbs), this was a very informative reading: https://www.theguardian.com/society/2016/apr/07/the-sugar-co...

Overall, I don't know of a lot of good science regarding which fats are better for you and which are actually bad. After all it was not until recently that it was admitted that the relationship between cholesterol in the blood and cholesterol is uncorrelated and not at all understood. Similarly even for calories, just because a food has X calories, does not mean you actually absorb all of those calories, let alone how the body uses them.

For the rule of thumb, I have no specific references and it is general knowledge I've picked up reading on nutrition. It could very well be wrong. I believe there is something to it, for example, coconut oil is relatively good for a person and has a low melt point, where-as bacon grease and steak gristle are pretty certainly terrible for a person.

Trying to find some references, I was not able to find the original reading where I stumbled upon that idea. This was a decent read though that I just came across: https://www.healthline.com/nutrition/healthy-vs-unhealthy-fa... (YMMV)

[mrguyorama]

Well.... Fats can be bad in that they are calorie dense foods, and thus it's easy to add more calories than you should to food with them.

It's significantly harder to be fat eating nothing but broccoli, but I could continuously gain weight eating only 250g of vegetable oil per day.

Sugar is bad for exactly the same reason IMO