[xurukefi]

I didn't check the science, but I'm pretty confident that "feeling full" is a matter of volume and not of calories. At least in my personal experience a really dumb and easy way to lose fat without feeling hungry was to eat food with a low calorie density.

[gohrt]

Not just volume, but the biochemical process of digestion. For example, food that takes longer to digest has more volume for longer time in your body. There are also complex interactions of chemical secretions to regulate chemistry in digestion.

[Practicality]

What foods are you referring to as "low calorie density foods"? I can imagine that most vegetables fit this classification... but why would you state it this way unless you are referring to something else?

[xurukefi]

I would define caloric density as the ratio of calories to weight. Refined sugar has a caloric density of 3.87 (387 kcal per 100gr), which is quite high. Most vegetables and fruits will probably have a caloric density <= 1. But I would also classify something like chicken breast (1.65) or turkey meat (1.89) as "low" in terms of caloric density. But it's not really about setting a threshold. It's more about being aware of how many calories you actually get per gram of food. It can make quite a big difference.

[hx87]

The goal isn't to "feel full", but to feel full and good for a long period of time. Otherwise, I might as well gorge myself on isotonic water.

[xurukefi]

I wasn't suggesting that feeling full is the goal. I was just trying to argue that calorie density is an important issue when it comes to obesity and overeating. Eating healthy food is, of course, important. But eating too much healthy food is not healthy ;).

If I had to choose between eating too much healthy food and eating enough unhealthy food, I would probably choose the latter. I think obesity is a bigger problem than poor nutrition.

[hx87]

Why would I eat too much if I eat calorie-dense foods? How full I feel in the long term has little to do with volume and more to do with how many calories I eat and how quickly they are digested.