[lumost]

If portions are the problem then processed food should be fine, why is it that processed food always comes in larger portions?

Why do consumers often think that the smaller portion is more filling when eating a properly proportioned french meal than the equivalent calories from McDonalds?

[handrous]

Guesses:

Some of it's food culture. Giant portions are normal so you don't think twice about piling your plate high. Norms (and, yes, judgement/shaming) about consumption affect patterns of same. Snacking, even heavy snacking, between meals, is common. This may be suppressed elsewhere by stronger "you eat at meal times—if not exclusively, then nearly so" norms, and snack-availability that's about what you'd expect, given those norms.

Some people think our commonly-accessible "good" food (fruits, veggies, not from specialty stores, just the main produce section of normal grocery stores) are a lot worse than what's normal in some other, healthier countries. I don't have enough experience to claim anything definitive on this, but what experience I do have does support it. If "good" food doesn't taste as good as elsewhere, or if getting something as good as others' normal produce requires special shopping and much higher prices, maybe one tends to reach for umami-bomb fat+starch garbage, which is both kinda-addictive and not very filling.

A lot of our standard cooking is tied up heavily with giant portions. We even seem to do this with imported cuisines, for whatever reason. Not-especially-good food in giant portions. Heaping plates of mediocre pasta+sauce as our image of Italian food, Mexican food with bottomless chips & salsa (and huge, cheese-slathered plates for the entrees), that kind of thing. I guess that's more of the food-culture thing.

I doubt any of these are all of the reason, and maybe none of them are correct at all.

[vorpalhex]

There is a theory (and I want to stress that it's theory, not fact) that many processed foods may not trigger our indicators of satiety. Some foods trigger satiety better than others, and we have pretty good evidence that a lot of sugars don't cause satiety.

On the other hand, foods like rice, potatoes, etc do.

[1] https://www.webmd.com/diet/features/satiety-new-diet-weapon (soft ref, appropriate grain of salt)

[2] https://pubmed.ncbi.nlm.nih.gov/27125637/

[KptMarchewa]

Because it is. It's relatively easy to consume 2000 calories in one sitting in McD, while few people have the stomach to stomach the same amount of calories in salad, without sugary drinks.

[AnIdiotOnTheNet]

I am not operating off any data here, and as far as I can tell neither are you so that seems fair, but it is quite possible that our conception of what is "filling" or "satisfying" is intrinsically tied to the cost of the meal. Processed food and fast food are cheaper and we know it, so if we get less of it, it is possible that that fact alone makes it less satisfying.

[handrous]

> Processed food and fast food are cheaper and we know it, so if we get less of it, it is possible that that fact alone makes it less satisfying.

Food pricing, especially at chain restaurants and fast-food joints, tends to support this. It's not uncommon to pay 20% more for double the food, either because larger sizes aren't much more expensive than smaller ones, or thanks to "combo" meals. Restaurants seem to be optimizing for total sales, not margin on individual items, based on how they price—in many cases their entire menu seems to exist only to make the "combo meal" look like a good deal, but of course it may be more food than you really wanted.

To say nothing of the phenomenon of all-you-can-eat buffets...