How much protein to eat while cutting SEO Brief & AI Prompts

Protein needs during a cut are generally higher than maintenance and are best expressed relative to lean body mass: evidence-based guidance for resistance-trained individuals in moderate-to-large deficits is about 2.3–3.1 g/kg lean body mass (≈1.05–1.41 g/lb LBM); when using total bodyweight as a simpler proxy, a practical range is roughly 1.6–2.4 g/kg bodyweight. That range balances muscle protein synthesis and nitrogen balance during energy restriction, and produces clear gram targets (for example, a 70 kg person at 15% bodyfat has ~59.5 kg LBM and would target ~137–184 g protein/day using the LBM range above).

The mechanism driving these targets is the need to preserve muscle protein synthesis (MPS) while in a caloric deficit, measured in studies using techniques such as tracer amino‑acid kinetics and DEXA for body composition. Researchers and practitioners including Helms et al. and Stuart Phillips frame protein prescriptions by LBM rather than total mass because grams protein per kg bodyweight underestimates needs for leaner trainees. Protein timing during cutting interacts with total intake: spreading 3–4 meals to hit per‑meal leucine thresholds—supported by MPS and nitrogen balance models—improves retention compared with skewed distributions, and tools like DEXA or validated skinfold formulas help set the LBM denominator.

A common and consequential nuance is that using total bodyweight instead of lean body mass for g/kg calculations systematically underfeeds protein for lean trainees, which undermines retention. For example, a 75 kg lifter at 15% bodyfat has 63.75 kg LBM; applying 1.6 g/kg total weight yields 120 g protein, whereas 2.3 g/kg LBM yields ~147 g — a 27% difference. Another frequent mistake is prescribing a single blanket number (e.g., 1.6 g/kg) irrespective of deficit severity or training volume; larger deficits and higher training intensities typically require intake toward the upper LBM range. Practical per-meal targets that satisfy leucine threshold and protein distribution meals guidance are roughly 20–40 g protein or about 0.24–0.40 g/kg per meal for most trainees.

A practitioner-ready approach is to estimate lean body mass (DEXA, calibrated BIA, or validated skinfolds), choose a protein target within the LBM range based on deficit size and training intensity (mild deficit ~2.0 g/kg LBM, aggressive deficit ~2.6–3.0 g/kg LBM), and distribute intake across 3–4 meals that meet the leucine threshold (~25–35 g protein per meal for many). This article provides a structured, step‑by‑step framework for calculating targets, timing intake, and troubleshooting common body‑type and training scenarios.