Are all calories the same?

In theory, a calorie is the same in all foods, but not when you consider how the body responds to calories from different sources. A chocolate chip muffin, for example, is chock-full of refined sugar and unhealthy fat that will likely get stored in your fat cells. This happens due to the spike in insulin that occurs when you eat that tasty muffin. The insulin tells your body to store the excess calories as fat. Eating a deli sandwich on whole-grain bread with bell peppers, sprouts, and avocado, on the other hand, won't cause the same surge in insulin and, in fact, requires time and an expenditure of energy to break down its proteins, healthy fats, and complex carbohydrates. The sandwich will keep your energy sustained and balanced.

Theoretically, a calorie is a calorie. The big differences are how our body responds to the calories we consume and how those calories make us feel.

Consider the following example. Both a 24-ounce sugar-sweetened beverage and a grilled chicken sandwich (3 ounces grilled chicken, small whole wheat bun, lettuce, tomato, onion) both contain ~250-275 calories yet the body’s metabolic response of these two items will be very different. How we feel after eating these two items would also be distinct. Because the beverage only contains simple carbohydrates and requires little digestion, it is quickly absorbed into the blood stream, causing a rapid rise in blood glucose. The chicken sandwich, on the other hand, is a combination of complex carbohydrates (including fiber) and protein. The fiber and protein both help to slow digestion and absorption, resulting in a slower, steadier rise in blood glucose. Foods that include calories from fiber and protein also help with satiety, keeping us feeling full for a long period of time.

These differences in how the calories are processed and how they make us feel can have significant implications for weight management.