Guess which meal has more calories: a small tuna-salad sub or 1½ cups of whole wheat pasta mixed with a cup of frozen veggies, sautéed in garlic and olive oil and topped with 2 tablespoons of freshly-grated parmesan? And now guess which meal is likely to be more filling?

Both the sandwich and the pasta tally in at around 530 calories each. But when it comes to satiety (the feeling of being full), not all calories were created equal. While some foods pack a hefty caloric punch into just a few bites, other foods let you eat and eat and eat for the same number of calories. And believe it or not, depending on their composition, such foods can be just as filling if not more.

The amount of calories a food contains for a certain amount of volume is referred to as its energy density. If a food is considered to be energy dense, that means it has a lot of calories in a small amount of food. On the other hand, foods with low energy density pack the same number of calories into a much bigger serving size.

Two things that add bulk to a food without adding calories (and therefore make it more filling) are water and fibre. Many fruits and vegetables have high water and fibre contents, making this so-called "rabbit food" more filling than it may seem. As well, foods that are high in fibre, such as whole grain products, can take longer to digest, making you not only feel full, but for a longer period of time.

Hunger can be a major obstacle for many people who are trying to lose weight. But incorporating foods into your diet that give you more bang for your caloric buck can be a sound strategy for beating hunger pangs. Consider munching on popcorn for a snack, tossing some vegetables in with that spaghetti, and starting meals off with a salad or bowl of soup - all ways you can increase the bulk in your diet without increasing the bulk on your body!

Written and reviewed by the MediResource Clinical Team