Note: Single-source report; awaiting corroboration.
Food contains macronutrients—proteins, carbohydrates, and fats—that provide the energy needed for bodily functions and supply essential building blocks for cells, including the ability to fight diseases. Vitamins and minerals, classified as micronutrients, are required in smaller amounts but are vital for healthy development and disease prevention. The Dietary Guidelines for Americans offer science-based recommendations on maintaining a balanced diet and are updated every five years to reflect evolving knowledge in nutrition.
Experts suggest adults consume 10% to 35% of calories from protein, 25% to 35% from fat, and 45% to 65% from carbohydrates, while staying within recommended calorie limits and choosing nutrient-rich foods and drinks. Resources like Nutrition Facts labels and websites such as Nutrition.gov can help individuals identify nutrient content in foods.
Proteins are broken down into amino acids, which help build muscles, skin, and organs, and assist in breaking down toxins. Proteins also serve as an energy source and tend to provide a stronger sense of fullness compared to carbohydrates. Carbohydrates remain the preferred immediate energy source, as they are converted into glucose—a sugar used by nearly all cells in the body. Carbohydrates are categorized as simple carbohydrates (sugars), complex carbohydrates (starches), and fiber. Simple carbohydrates consist of one or two sugar molecules and are digested and absorbed quickly.
Samantha Adas, a nutritionist at NIH, noted that although the body may still function without optimal amounts of macronutrients, it might not perform at its best. Dr. Christopher Lynch, acting director of the NIH Office of Nutrition Research, also highlights carbohydrates' key role as the main energy source.