Question

Carbohydrates are different than fats. Why do people who tend to eat a lot of carbohydrates from soft drinks or sugary foods usually gain body fat?

nutrition

Answer 1

Ans: Although carbohydrates are different than fats but eating carbohydrate-rich foods like soft drinks and sugary foods can induce the process of lipogenesis that is defined as the synthesis of fatty acid from glucose or from any other nonlipid substance.

To understand how carbohydrate-rich foods cause gain in body fat first understand what happens to the carbohydrates that we eat?

Digestion of carbohydrate:

1. Carbohydrates are digested to form glucose which is absorbed by the blood in the small intestine.
2. Excess glucose comes into the liver where it is converted into glycogen (glycogenesis) for future use.

What happens when a person eats a lot of carbohydrates?

1. When our food is loaded with carbohydrates then the liver stops converting glucose into glycogen as it's capacity to store glycogen is over.  
2. At this point, lipogenesis will start and pyruvate (product of glycolysis starts from glucose) will convert into acetyl Co-A which will further convert into fatty acid. These fatty acids are stored as fats in the body.

In this way eating, excess carbohydrates will cause a gain in body fat.