Different types of foods have different calorie densities. Fats have 9 calories per gram. Protein and carbohydrates have only 4 calories per gram. When we sit down to eat, we tend to eat the same number of spoonfuls, or volume of food. It’s a pretty fundamental response. So if each bite averages just 5 calories (such as an apple), you’re in a far better situation for losing weight than if each bite averaged 50 calories (a bite of a double cheeseburger). To lose or maintain one’s weight it is important to eat a lot of low calorie density foods. Fruits and vegetables have a low calorie density. Low-calorie-dense foods don’t pack a lot of calories per bite. Fruits and vegetables have both water and fiber making them big and heavy and therefore more filling. This is why fruits and vegetables are so important (besides their large amounts of vitamins, fiber, and antioxidants). Starting every meal with either a piece of fruit or salad can help one lose weight as you get filled up on less calories. Food loaded with sugar, simple carbohydrates, and fat tend to be high calorie density foods. You get a lot of calories per bite and they do not fill you up so you eat more. It becomes very easy to overeat and gain weight. Examples of high calorie dense foods include cereals, dried fruit, breads, cheeses, pretzels, granola bars, cookies, peanuts, ground beef and doughnuts. Sticking to low calorie density foods helps you to remain full and feel satisfied after meals. Therefore you avoid hunger and still take in less calories helping to shed those extra pounds.