Macronutrients (Macros)

Macronutrients (macros) are the three nutrient classes that provide energy: protein, carbohydrate, and fat. Total calorie intake is the sum of the calories provided by each macro. Calorie tracking apps frequently track macros separately (“macro tracking”) in addition to total calories.

Caloric values of each macronutrient

The standard caloric conversions (Atwater factors):

• Protein: 4 kcal per gram
• Carbohydrate: 4 kcal per gram
• Fat: 9 kcal per gram
• Alcohol (not technically a macro, but energy-yielding): 7 kcal per gram

These are first-order approximations. Different foods have slightly different metabolizable energy due to fiber (which is partially digestible), processing (which affects digestibility), and individual factors (gut microbiome composition affects energy extraction). For practical tracking, the Atwater factors are accurate to within ~3%.

Common macro targets by goal

General health (no specific goal):

• Protein: 0.8-1.2 g/kg bodyweight (~15-20% of calories)
• Fat: ~25-30% of calories
• Carbohydrate: remainder (~50-60% of calories)

Weight loss with muscle preservation:

• Protein: 1.6-2.2 g/kg bodyweight (~30-35% of calories in a deficit)
• Fat: ~25-30% of calories
• Carbohydrate: remainder (~35-45% of calories)

Endurance athletes:

• Carbohydrate: 5-12 g/kg/day depending on training volume (often 50-65% of calories)
• Protein: 1.2-1.4 g/kg
• Fat: remainder

Keto / low-carb:

• Fat: 70-75% of calories
• Protein: 20-25% of calories
• Carbohydrate: 5-10% of calories (often expressed as <50g net carbs/day)

Why macro tracking matters more than calorie-only for some users

For weight loss alone, calorie tracking is sufficient — a deficit produces weight loss regardless of macro composition. For body recomposition (gaining muscle while losing fat), protein intake matters because muscle protein synthesis is bounded by protein availability. For specific clinical conditions (diabetes, kidney disease), carb or protein restriction is medically indicated.

The published evidence on protein and body composition during caloric restriction (Helms 2014; Phillips & Van Loon 2011; Aragon 2017) is consistent: protein intake at the upper end of recommendations (1.6-2.2 g/kg) meaningfully outperforms RDA-level intake for muscle preservation in a deficit.

Which apps handle macros best

Apps with first-class macro tracking and coaching:

• MacroFactor — algorithmic macro coaching, weekly adjustments
• Cronometer — most accurate macro values per entry, plus 80+ micros
• Carb Manager — keto-specific with net carbs as first-class
• MyFitnessPal Premium — macro targets and reports
• Lose It! Premium — macro tracking included

Most mainstream trackers handle macro tracking adequately in Premium tiers. The algorithmic coaching (macros adjusted weekly based on weight trend) is only in MacroFactor.

For the long-form explainer on when macro tracking is necessary, see our calorie tracking vs macro tracking blog post.