Carbohydrate

Macronutrient · starch, sugars, fiber

What does Carbohydrate do in your body?

Starches and sugars are broken down to simple sugars like glucose, absorbed, and used for energy or stored as glycogen.

How it works, step by step

  1. Salivary amylase starts cutting starch.
  2. Pancreatic amylase continues in the small intestine.
  3. Brush-border enzymes release glucose, fructose and galactose.
  4. Insulin helps cells take up glucose or store it as glycogen.

What does Carbohydrate do?

Main fuel for the brain and for high-intensity exercise. Provides about 4 kcal per gram. Stored as glycogen in liver and muscle.

Where does Carbohydrate act in the body?

Brain, red blood cells (which rely almost entirely on glucose), muscle, liver.

Which foods contain Carbohydrate?

Grains, potatoes, legumes, fruit, vegetables, milk; added sugars in sweets and drinks.

How much Carbohydrate do adults need?

RDA: 130 g/day (based on the brain's minimum glucose use). AMDR: 45–65% of energy.

What happens with too little Carbohydrate?

Very low intakes shift the body to producing ketones; this isn't deficiency, but performance in high-intensity exercise can drop.

Can you get too much Carbohydrate?

Context matters: high intakes of added sugars are linked with tooth decay and poorer diet quality; whole-food carbohydrates come with fiber and micronutrients.

What does Carbohydrate interact with?

Fiber, fat and protein in the same meal slow how fast glucose enters the blood.

What is known and unknown about Carbohydrate?

Carbohydrate isn't intrinsically good or bad. Source, amount, fiber and overall diet matter.

Evidence & sources

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General education only, not medical advice. Drafted Oct 2026 · pending qualified expert review.