What is it?

Carbohydrates are one of the three main macronutrients that provide energy to the body. They are found in many foods and are broken down into glucose (sugar) during digestion to fuel the body’s cells, tissues, and organs. Carbohydrates come in three main types:

  • Simple carbohydrates: Found in sugars like glucose and fructose, providing quick energy.
  • Complex carbohydrates: Found in starchy foods and whole grains, offering sustained energy due to slower digestion.
  • Fiber: A type of carbohydrate that isn’t digested but supports digestive health.

Why is it needed, and how much do we need?

Carbohydrates are the body’s primary energy source, supporting brain function, muscle activity, and overall metabolism. The Dietary Guidelines for Americans 2020-2025 recommend that 45–65% of daily calories come from carbohydrates, primarily from nutrient-dense, whole-food sources.

For a 2,000-calorie diet, this equals 225–325 grams of carbohydrates per day.

What happens if you eat too much?

Excess carbohydrate intake, particularly from refined or sugary sources, can lead to:

  • Weight gain due to surplus calorie consumption
  • Blood sugar spikes, increasing the risk of type 2 diabetes
  • Elevated triglycerides, contributing to heart disease

What happens if you eat too little?

Insufficient carbohydrate intake can cause:

  • Fatigue and low energy levels, as the body lacks its primary fuel source
  • Muscle breakdown, as the body may use protein for energy
  • Ketosis, a condition where the body burns fat for fuel, which may cause nausea or headaches

What foods are rich in carbohydrates?

  • Healthy sources:

    • Whole grains: Brown rice, quinoa, oats, and whole wheat bread
    • Fruits: Apples, bananas, oranges, and berries
    • Vegetables: Sweet potatoes, carrots, peas, and corn
    • Legumes: Lentils, beans, and chickpeas
    • Dairy: Milk and yogurt

  • Less healthy sources:

    • Refined grains (white bread, pastries)
    • Sugary beverages
    • Processed snacks and desserts

For more details, visit the MedlinePlus Guide to Carbohydrates and the Dietary Guidelines for Americans.