Hunger is due to the hormonal response to low blood sugar and a concurrent empty stomach (which actually has pressure sensors when full to reduce hunger even if blood sugar is low). Salad or vegetables have the most bulk per calorie so they reduce hunger the most via stomach filling. Starches, such as oatmeal, high fiber cereal or a microwaved yam (eats like an energy bar) are higher in calories than vegetables but boost blood sugar for energy without the blood sugar swing (and crash) associated with rapidly-digesting carbs (e.g. cereals high in sugar, white bread or crackers, etc). Some fruit (e.g. a banana) digest faster than others (e.g. an apple) due to the difference in fiber and sugar content, so an apple is more filling. Protein and fats (e.g. nuts) are not as filling in the stomach but result in a hormonal response that reduces hunger more than carbs (meaning starches, fruit and vegetables) over the course of 2 or 3 hours. So, in summary, to reduce hunger immediately eat some vegetables (like broccoli, cauliflower, or some carrots, although the latter are higher in calories than most vegetables), to reduce hunger for up to an hour and boost energy a bit at the same time without a blood sugar swing eat 50-100 Cal of fruit or whole-grain starch, and to reduce hunger for more than an hour include some nuts or nut butter as a fat source (or some olives with the vegetables for flavoring). Snack examples are: A slice of whole grain bread with a thin layer of nut butter and a small plumb, or a rye cracker with some veggies and a few olives. The simpler approach of just using a piece of fruit or some almonds is also fine. But if a person has serious mid-afternoon cravings that cuts into their concentration and nags them day after day, a snack that more aggresively addresses all the components of hunger should be considered.