# Daily Calorie and Protein Targets

phase.fitness · Methodology · Training principles · Updated 14 September 2026 · HTML version: https://www.phase.fitness/methodology/nutrition-targets

> How this document is used: it is one of the documents the phase.fitness generator reads before writing a phase. The principles below are passed to the model as context and the numbers become bands the program has to respect. The references are stripped from the prompt and kept here.

Training decides what the body is asked to do; energy and protein decide what it can build or keep. A program aimed at losing fat or gaining muscle works only as well as the intake behind it. This document sets out how daily calorie and protein targets are estimated from a profile and a goal, and how far to trust the estimate.

## Resting energy expenditure

Resting energy expenditure is estimated with the Mifflin–St Jeor equation, which in a systematic comparison of predictive equations came within 10% of measured values in more people, lean and obese, than any other equation.

| Sex | Resting energy expenditure (kcal/day) |
|---|---|
| Men | 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5 |
| Women | 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161 |

When sex is not given, the constant is the midpoint of the two, −78.

## Activity

Total energy expenditure is resting energy expenditure multiplied by a physical activity level. International energy requirement reports group lifestyles into three bands: sedentary or light activity 1.40–1.69, active or moderately active 1.70–1.99, vigorous 2.00–2.40.

| Training sessions per week | Activity level used |
|---|---|
| 0–2 | 1.55, light |
| 3–4 | 1.75, moderately active |
| 5 or more | 1.90, active |

Training sessions are strength and cardio days together. A vigorous level is not assigned from training alone: it describes hours of hard physical work every day, which a training schedule does not show.

## Calories by goal

| Goal | Daily calories |
|---|---|
| Fat loss | 80% of maintenance |
| Muscle gain | 110% of maintenance |
| Strength, general fitness, endurance | maintenance |

**Fat loss.** Fat loss is driven by a sustained deficit, and slower rates of loss preserve more lean mass. In elite athletes, cutting intake by about a fifth produced a weekly loss near 0.7% of body weight and lean mass increased, while a deeper cut lost weight faster and gained no lean mass. For lean, trained people the recommended pace is roughly 0.5–1% of body weight per week.

**Muscle gain.** Gaining lean mass is driven by a sustained surplus. Recommendations for natural lifters are a surplus of about 10–20% with a weight gain near 0.25–0.5% of body weight per week; the low end limits fat gain.

**Everything else.** Strength, general fitness and endurance programs eat at maintenance.

## Protein

| Goal | Daily protein |
|---|---|
| Fat loss, body fat known | 2.3 g per kg of fat-free mass |
| Fat loss, body fat unknown | 2.0 g per kg of body weight |
| Every other goal | 1.6 g per kg of body weight, up to 2.2 |

Across the research on protein and resistance training, gains in fat-free mass stopped increasing beyond about 1.6 g per kg per day. A daily intake of 1.4–2.0 g per kg is sufficient for most exercising people, and ranges up to 2.2 g per kg are recommended for lifters trying to gain muscle. In a deficit, lean, resistance-trained people may need 2.3–3.1 g per kg of fat-free mass to keep their muscle. Without a body-fat estimate, fat-free mass is unknown, so the target falls back to the top of the general range per kg of body weight.

## A worked example

A 30-year-old man, 180 cm and 80 kg, training four days a week to build muscle:

- resting energy expenditure: 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal;
- maintenance: 1,780 × 1.75 = 3,115 kcal, shown as 3,100;
- target: 3,115 × 1.10 = 3,427 kcal, shown as 3,450;
- protein: 1.6 × 80 = 128 g, shown as 130 g, up to 175 g.

The same man cutting fat eats 2,500 kcal (80% of maintenance, rounded) and, without a body-fat estimate, 160 g of protein.

## How far to trust the numbers

These are starting points, rounded to the nearest 50 kcal and 5 g. An equation that is within 10% for most people is still 10% away for some. The real test is the scale: if weight does not move in the intended direction at the intended pace over two to three weeks, intake changes, not the goal.

- **Very lean or very muscular people** burn more at rest than a weight-based equation predicts, so their maintenance is usually higher than the estimate.
- **People with obesity** are estimated less accurately by every equation; a body-fat estimate makes the protein target more realistic because it is counted on fat-free mass.
- **Hard physical jobs** raise daily expenditure beyond what training days describe. The activity level here counts training only, so the estimate is low for them.
- **Weekly averages matter more than single days.** Training days and rest days can differ; what decides the direction of body weight is the average across the week.

## References

- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition. 1990;51(2):241-247. doi:10.1093/ajcn/51.2.241
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association. 2005;105(5):775-789. doi:10.1016/j.jada.2005.02.005
- FAO/WHO/UNU. Human energy requirements: report of a joint FAO/WHO/UNU Expert Consultation. Food and Nutrition Technical Report Series 1. Rome: FAO; 2004.
- Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. International Journal of Sport Nutrition and Exercise Metabolism. 2011;21(2):97-104. doi:10.1123/ijsnem.21.2.97
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition. 2014;11:20. doi:10.1186/1550-2783-11-20
- Aragon AA, Schoenfeld BJ, Wildman R, et al. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 2017;14:16. doi:10.1186/s12970-017-0174-y
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports. 2019;7(7):154. doi:10.3390/sports7070154
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine. 2018;52(6):376-384. doi:10.1136/bjsports-2017-097608
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2017;14:20. doi:10.1186/s12970-017-0177-8

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