system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are some food with lower calories make our stomatch feels fuller than others with higher calories?

For example, i feel so full after eating just a bit of sweet potatoes, but can't get enough with the original potatoes!
gpt
Generally, we feel full when our stomach is full of food. Fibre fills up the stomach but doesn't really have much calories so makes us feel fuller. (vegetables have alot of fibre) 

There are however foods that 'hack' our fullness mechanism. For example, food that are rich in both fat and sugar (at roughly 50/50 ratio) stop us from feeling full so we eat alot more calories before we feel full.

So most 'bingeable' foods are those that have a 50/50 fat and carbs content (ice cream, cakes, donuts, pizza, crisps etc

Fat or carbs on their own don't do this and we feel full quickly after eating them separately.

The combination of fat and carbs in modern foods is supposed to be one of the biggest contributing factors to the obesity epidemic.