# What are macros?

Macronutrients—protein, carbohydrates, and fat—are the three nutrients that supply calories. Protein and carbohydrates provide about 4 kilocalories per gram; fat provides about 9. The Institute of Medicine suggests adults get 10–35% of calories from protein, 45–65% from carbohydrates, and 20–35% from fat (Acceptable Macronutrient Distribution Range).

## Key numbers

- Protein and carbohydrates: about 4 kcal per gram; fat: about 9 kcal per gram (general Atwater factors). [1]
- AMDR for adults: protein 10–35%, carbohydrates 45–65%, fat 20–35% of daily calories. [2]
- Build often targets about 1 g protein per lb of body weight when you enter weight—a high-protein meal-planning default, not a medical guideline. (MFM methodology)

## Energy density: protein and carbohydrates supply 4 kcal per gram; fat supplies 9 kcal per gram.

- **Protein:** 4 kcal/g
- **Carbs:** 4 kcal/g
- **Fat:** 9 kcal/g

## Why do 4/4/9 matter?

Food labels and meal planners convert grams to calories with these factors. If you know your calorie target and a percent split, you can work backward to gram targets for protein, carbs and fat—always in that order on Macro Friendly Meals.

## What is AMDR?

The Acceptable Macronutrient Distribution Range is a band of intakes that provide enough energy and nutrients for most healthy adults. It is not a single prescription—athletes, clinical needs and personal preference can sit inside or outside these bands with professional guidance.

## Acceptable Macronutrient Distribution Ranges (AMDR) for adults: percent of total daily calories from each macro.

- **Protein:** 10–35% of calories — IOM Acceptable Macronutrient Distribution Range for adults.
- **Carbs:** 45–65% of calories — IOM Acceptable Macronutrient Distribution Range for adults.
- **Fat:** 20–35% of calories — IOM Acceptable Macronutrient Distribution Range for adults.

## How MFM uses this

- [Build](https://macrofriendlymeals.com/) — plans meals to at least your protein, carb and fat gram targets (P, C, F order) using the same 4/4/9 math.

- [Macros Left](https://macrofriendlymeals.com/macros-left) — shows recipes that fit what you have not eaten yet against the same targets.

- [Protein guide](https://macrofriendlymeals.com/learn/protein) — explains how MFM sets its high-protein default and how federal protein ranges compare.

## What we can't do (yet)

- Food and recipe numbers on the site are editorial estimates—not lab-verified copies of USDA rows.

- This page does not set a medical macro prescription; kidney disease, diabetes and other conditions need clinician-set targets.

## Questions

### What are macronutrients?

Macronutrients are protein, carbohydrates and fat—the nutrients that supply calories. Protein and carbohydrates provide about 4 kilocalories per gram; fat provides about 9. Together they make up nearly all the energy in food.

### How do you convert macros to calories?

Multiply protein grams by 4, carbohydrate grams by 4, and fat grams by 9, then add the results. Nutrition Facts labels and meal planners use the same general factors.

### What is the AMDR for protein, carbs and fat?

For adults, the Institute of Medicine Acceptable Macronutrient Distribution Ranges are about 10–35% of calories from protein, 45–65% from carbohydrates, and 20–35% from fat. Individual needs can fall inside or outside these bands.

### How does MFM order macros?

Macro Friendly Meals always shows and plans protein, then carbs, then fat (P, C, F). Build and Macros Left use the same gram targets and 4/4/9 calorie math.

### Are MFM macro numbers verified against USDA?

No. Recipe and Food Finder macros are editorial estimates maintained on the site. Use them for meal planning, and check package labels when precision matters.

General education, not medical advice.

## Sources

1. [NCBI Bookshelf — Dietary Reference Intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (Macronutrients)](https://www.ncbi.nlm.nih.gov/books/NBK234922/)
2. [NCBI Bookshelf — Dietary Reference Intakes for Energy](https://www.ncbi.nlm.nih.gov/books/NBK231301/)

Last reviewed: 2026-10-23 by MFM
Reviewed against: NCBI DRI macronutrients report (Atwater factors and AMDR); NCBI DRI for Energy

Cite as: Macro Friendly Meals, "What are macros?", https://macrofriendlymeals.com/learn/macros, reviewed 2026-10-23.