The Acceptable Macronutrient Distribution Range (AMDR) is a set of nutritional guidelines that provides a recommended proportion of energy intake from the three main macronutrients: carbohydrates, fat, and protein. This framework is a core component of the Dietary Reference Intakes (DRI), which are established by the Food and Nutrition Board of the Institute of Medicine (IOM). The AMDR is designed to guide individuals and health professionals toward a dietary pattern that supports overall wellness and helps reduce the risk of developing chronic diseases. It is expressed as a percentage of a person’s total daily calorie intake, offering flexibility within a scientifically sound range.
Defining the Acceptable Macronutrient Distribution Range
Macronutrients are the components of food that the body requires in large quantities: protein, fat, and carbohydrate. The AMDR provides a range for each to ensure a person receives adequate essential nutrients while managing the balance of energy sources. These ranges are established with two main goals. The first goal is to ensure a sufficient intake of essential amino acids and fatty acids, which are necessary for countless bodily functions.
The second goal is to reduce the risk of chronic diseases such as heart disease and type 2 diabetes. Consuming energy outside of these defined proportions may increase the likelihood of developing these health issues. A diet that is disproportionately high in one energy source often leads to a deficiency or excess of another, which can disrupt metabolic balance over time.
The Specific Percentage Ranges for Macronutrients
The AMDR provides numerical values for the percentage of total daily calories that should come from each macronutrient for adults.
Carbohydrates (45–65%)
Carbohydrates are the body’s primary source of energy for the brain and physical activity. They are recommended to make up 45–65% of an adult’s total daily calorie intake. This wide range allows for flexibility while ensuring a consistent supply of glucose. Consuming carbohydrates below this range may make it difficult to meet energy needs and obtain sufficient fiber and micronutrients found in whole grains and vegetables.
Fat (20–35%)
The AMDR for dietary fat is set at 20–35% of total daily calories. Fat is necessary for the absorption of fat-soluble vitamins (A, D, E, and K) and for providing essential fatty acids. The range supports these biological processes without contributing to an excessive intake of saturated or trans fats, which are associated with a higher risk of heart disease.
Protein (10–35%)
Protein is recommended to constitute 10–35% of total daily calorie intake. Protein supplies the amino acids needed for the growth, repair, and maintenance of all body tissues and is involved in hormone and enzyme production. The upper limit accounts for individual variation, such as for highly active individuals who may benefit from a higher protein intake for muscle repair.
Using AMDR to Achieve Nutritional Balance
The AMDR offers a practical framework for dietary planning. Individuals use these ranges to structure a balanced daily intake that ensures all macronutrient needs are met proportionally. For example, a person consuming 2,000 calories daily would aim for 900 to 1,300 calories from carbohydrates, 400 to 700 calories from fat, and 200 to 700 calories from protein.
Adhering to the AMDR helps achieve a nutritional balance distinct from the Recommended Dietary Allowance (RDA) for individual nutrients. While the RDA focuses on the minimum amount needed to prevent deficiency, the AMDR focuses on the distribution of energy for long-term health and disease prevention.
Consistently eating outside of these recommended ranges can have negative health implications. Diets persistently high in fat, especially unhealthy types, can increase cardiovascular risk, while inadequate protein may lead to loss of lean muscle mass and impaired immune function. The AMDR serves as a broad, flexible guide to promote a sustainable and healthy energy distribution.