Carbohydrates in Food: How the Body Handles Them

Do carbohydrates in food make us fat? Or do we gain weight because we overeat calories and/or don't get enough physical activity?

KEY POINT: Carbohydrates break down into sugars.

The two main hypotheses for why we gain weight -- Lipophilia and Caloric Balance -- give us two radically predictions about what should be true in the real world.

Caloric Balance tells us that 'a calorie is a calorie.' Calorie quantity matters; calorie "quality" doesn't.

Lipophilia, on the other hand, says that quality of calories does matter. In particular, when we eat carbohydrates, that causes an increase in blood glucose levels and serum insulin, which in turn leads to the storage of fat in the fat tissue.

How does carbohydrate digestion work? Here are a few articles that appear to explain the biochemistry in detail, if you're interested:

How Carbohydrates Are Digested And Used By The Body

Your Digestive System and How It Works

Digestion, absorption and energy value of carbohydrates

For our purposes, the takeaway is that our bodies digest and utilize the calories from carbs very, very differently from how our bodies digest and utilize the calories from proteins and fats. Since this proves that all calories are not "equal," this supports the Lipophilia and challenges Caloric Balance.