Catalyst Performance
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Catalyst Performance
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Body Composition
Your daily protein target in grams, from your body weight. Two numbers, and they are not a contradiction: a floor you should hit every day, and a higher target if you are training hard to build or keep muscle.
After 40, muscle is the tissue that protects your healthspan, and protein is half of how you keep it, the other half being resistance training. Most people eat far less than they think, and the shortfall shows up as muscle quietly lost over years. Hitting a protein floor is one of the highest-return, lowest- cost changes you can make. It matters most in two situations: in a fat-loss deficit, where protein defends the muscle you have, and on a GLP-1 medication, where appetite is suppressed and hitting the target becomes deliberate rather than automatic. If that is you, our GLP-1 muscle-loss calculator shows how much of your weight loss is likely muscle, and the GLP-1 Muscle Protocol turns the protein target into meals.
Sources: Morton RW et al. 2018, Br J Sports Med (meta-analysis, gains maximise ~1.6 g/kg/day) and the ISSN Position Stand 2017 (build-and-maintain range 1.4 to 2.0 g/kg).
| Band | g per kg per day | Who it is for |
|---|---|---|
| Floor | 1.2–1.6 | Everyone, the daily baseline to hit consistently |
| Target | 1.6–2.2 | Training hard to build or keep muscle; the higher end in a deficit |
Want the full system, meals and all? The Muscle + Fat Loss Protocol turns these numbers into a Protein Playbook and a cookbook, structured across 12 weeks.
Cardiorespiratory
VO2 Max Calculator →
Strength
Grip Strength Test →
Body Composition
Waist-to-Height Ratio →
Stability
Sitting-Rising Test →
Overall
Fitness Age Calculator →
GLP-1 / weight-loss meds
GLP-1 Muscle-Loss Calculator →
Running
Running Pace Calculator →
Running
Heart Rate Zones Calculator →
Body Composition
Body Fat Percentage Calculator →
All calculators + the Healthspan Audit →