Cutting (Fat-Loss Phase)

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Explainer

In one line

A "cut" is a deliberate fat-loss phase run in a moderate deficit with high protein and maintained training, to reveal muscle built during a gaining phase.

Detail

Cutting is a structured fat-loss phase, typically following a muscle-gain phase ("bulk" — see Bulking (Muscle-Gain Phase)) in the bulk/cut cycle many lifters use. The aim is to lose fat while retaining the muscle built previously.

How it's run:

Moderate caloric deficit: size it to lose ~0.5–1% body weight/week (Helms et al. 2014; see Setting Calorie Targets for Fat Loss, Maintenance, and Gain, Safe Rate of Caloric Deficit and Weight Loss). In elite athletes who kept lifting, a 0.7%/week target (about a 19% cut in intake) added lean mass, while a 1.4%/week target (about a 30% cut) did not (Garthe et al. 2011). Leaner individuals should err slower and smaller to protect muscle (ISSN diets stand, 2017 edition). Crash approaches don't pay off: the 2026 ISSN stand says very-low-energy (under 800 kcal/day) and low-energy (800–1,200 kcal/day) diets lose more weight short term but have no long-term advantage over less aggressive restriction, and may cost more lean mass.
High protein: the 2026 ISSN stand says 1.9–3.2 g/kg of body weight per day can maximize lean-mass retention in lean, resistance-trained people in a deficit (the 2017 edition put it at 2.3–3.1 g/kg of fat-free mass). Total daily protein matters most; spreading it across at least three protein-rich meals a day may help further (see Protein-Sparing in a Caloric Deficit).
Maintain training intensity: keep lifting heavy/hard to signal muscle retention; some reduction in total volume is fine as energy drops.
Duration: run the cut long enough to reach the target, then transition to maintenance or a gaining phase rather than dieting indefinitely (chronic deficits risk low energy availability — see Low Energy Availability and RED-S).

The leaner one gets, the harder muscle is to keep and the more disciplined intake and recovery must be. Expect loss to slow: the body adapts to a deficit by spending less energy. The 2026 ISSN stand notes that adaptive thermogenesis (a drop in resting expenditure beyond what the lost tissue explains) isn't inevitable and may fade substantially once weight is stable, and it treats a plateau as a cue to practise holding the progress made. Planned spells at maintenance are one way to do that; the stand's position points don't single out diet breaks. See the broader playbook in Nutrition for Fat Loss.

Key facts

A cut = deliberate fat-loss phase, often after a bulk.
Moderate deficit sized to ~0.5–1% body weight/week (Helms 2014; Garthe 2011).
High protein: 1.9–3.2 g/kg of body weight for lean, trained lifters in a deficit (ISSN 2026; 2017 edition: 2.3–3.1 g/kg of fat-free mass), across at least three protein-rich meals.
Very-low/low-energy diets (<800 / 800–1,200 kcal/day): short-term loss only, no long-term edge (ISSN 2026).
Keep training intensity high to preserve muscle.
Time-limit the cut; avoid chronic deficits (low energy availability).

Connections

Bulking (Muscle-Gain Phase) — the gaining phase a cut follows.
Nutrition for Fat Loss — the full fat-loss playbook.
Protein-Sparing in a Caloric Deficit — protecting muscle while cutting.
Low Energy Availability and RED-S — risk of dieting too hard/long.

Sources

Position standAragon AA et al. International Society of Sports Nutrition position stand: diets for body weight reduction. J Int Soc Sports Nutr 2026;23(1):2740266 Published 2026-10-13 · DOI 10.1080/15502783.2026.2740266 · Accessed 2026-10-13
Position standAragon AA et al. International Society of Sports Nutrition position stand: diets and body composition. J Int Soc Sports Nutr 2017;14:16 (earlier edition, superseded by the 2026 diets for body weight reduction stand) Published 2017-06-14 · DOI 10.1186/s12970-017-0174-y · Accessed 2026-10-13
Position standJäger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr 2017;14:20 Published 2017-06-20 · DOI 10.1186/s12970-017-0177-8 · Accessed 2026-10-13
ReviewHelms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr 2014;11:20 Published 2014-08-15 · DOI 10.1186/1550-2783-11-20 · Accessed 2026-10-13
Randomised trialGarthe I et al. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab 2011;21(2):97–104 Published 2011 · DOI 10.1123/ijsnem.21.2.97 · Accessed 2026-10-13

Also cited in text

ISSN Position Stand: Diets for Body Weight Reduction (Aragon et al., J Int Soc Sports Nutr 2026;23(1):2740266; position statement read via PubMed abstract). Earlier edition: ISSN Position Stand: Diets and Body Composition (Aragon et al., 2017). ISSN Position Stand: Protein and Exercise (Jäger et al., 2017) — 2.3–3.1 g/kg/day in hypocaloric resistance-trained subjects (the diets stand and Helms 2014 express it per kg of fat-free mass). Helms, Aragon & Fitschen, J Int Soc Sports Nutr 2014;11:20 (abstract). Garthe et al., Int J Sport Nutr Exerc Metab 2011;21(2):97–104 (abstract).

Corrections (3)

2026-10-13 — Replaced the unsourced '~10–25% below TDEE' deficit band with rate-based guidance from primary sources: ~0.5–1% of body weight a week (Helms, Aragon & Fitschen 2014, J Int Soc Sports Nutr 11:20); in Garthe et al. 2011 (Int J Sport Nutr Exerc Metab 21:97–104) the 0.7%/week group cut energy intake by ~19% and gained lean mass, while the 1.4%/week target needed a ~30% cut and lean mass did not change; leaner people should lose more slowly (Aragon et al. 2017 ISSN). Also corrected the protein range to 2.3–3.1 g/kg of fat-free mass (Helms 2014; Aragon et al. 2017), not of body weight.
2026-10-13 — Added dated sources for the ISSN attributions. Re-read the full texts: Aragon et al. 2017 (ISSN diets and body composition) says the higher the baseline fat mass the more aggressive the deficit can be, that slower loss better preserves lean mass as people get leaner (citing Garthe's 0.7% vs 1.4%/week), and cites Helms' 0.5–1.0%/week; it gives 2.3–3.1 g/kg of fat-free mass for lean resistance-trained people in a deficit. Jäger et al. 2017 (ISSN protein) states the same range per kg of body weight. The protein stand is still the ISSN's latest on protein. RESOLVED 2026-10-13 (see next entry): a new ISSN position stand, 'diets for body weight reduction' (Aragon et al., J Int Soc Sports Nutr 23(1), doi:10.1080/15502783.2026.2740266, published 2026-10-13 per Crossref), may supersede the 2017 diets/body-composition stand; its full text could not be retrieved on 2026-10-13 (publisher blocks automated access, not yet in PubMed/Europe PMC), so these claims have not been reconciled against it and it is not cited as a source until read. No figure changed.
2026-10-13 — Reconciled against the new ISSN position stand 'diets for body weight reduction' (Aragon et al., J Int Soc Sports Nutr 2026;23(1):2740266, doi:10.1080/15502783.2026.2740266, published 2026-10-13), which supersedes the 2017 diets and body composition stand; added as a direct source, 2017 kept as the earlier edition. Position statement read via PubMed abstract (PMID 42867412), which carries all 15 official position points; the full text is blocked to automated access, so nothing beyond those 15 points is used. Changes: protein for lean, resistance-trained people in a deficit is now 1.9–3.2 g/kg of body weight (point 7); the 2017 edition's 2.3–3.1 g/kg of fat-free mass is kept and labelled. Added: total daily protein comes first, distribution second (point 5), spread across at least three protein-rich meals or eating occasions (point 4); very-low- and low-energy diets (<800 and 800–1,200 kcal/day) give more short-term loss but no long-term advantage and may increase lean-mass loss (point 2). Rewrote the unsourced line that diet breaks aid 'hormonal recovery': the 15 position points don't name diet breaks; they say adaptive thermogenesis is not inevitable and may fade substantially once weight is stable (point 11), and that plateaus are a cue to practise holding progress (point 13). The 0.5–1%/week rate (Helms 2014) and 'leaner people should lose more slowly' (2017 edition) are not restated in the 2026 position points and stay attributed to those sources. Resolves the OPEN item in the previous entry.

See how this applies in practice, with honest limits on what the plan changes.

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