How to Calculate GLP-1 Muscle Loss Risk Score

What is GLP-1 Muscle Loss Risk Score?

The GLP-1 Muscle Loss Risk Calculator estimates your risk of losing significant lean muscle mass while on GLP-1 therapy. It factors in your rate of weight loss, protein intake, resistance training frequency, age, and starting body composition to produce a risk score and actionable mitigation recommendations.

Formula

Muscle Loss Risk Score = (Rate of Loss Factor × 30) + (Protein Deficit Factor × 25) + (Age Factor × 20) + (Exercise Factor × 25)

RoL: Rate of Loss (lbs/week) — Current weekly weight loss rate
PI: Protein Intake (g/day) — Current daily protein consumption
RT: Resistance Training (sessions/week) — Weekly resistance training sessions
A: Age (years) — Patient age (risk increases after 50)
BF%: Body Fat Percentage (%) — Current body fat percentage if known

Step-by-Step Guide

1Enter your age, current weight, rate of weekly weight loss, and body fat percentage if known
2Input your daily protein intake and resistance training frequency
3The calculator produces a risk score from 0-100 (Low: 0-30, Moderate: 31-60, High: 61-100)
4Review personalized recommendations to reduce muscle loss risk

Worked Examples

Input

Age 55, losing 3 lbs/week, protein 60g/day, no resistance training

Result

Risk Score: 78/100 (HIGH). Rate of loss factor: 24/30, protein deficit: 22/25, age: 16/20, exercise: 16/25. Recommendations: increase protein to 120g, add 2x/week resistance training, slow loss to 1-2 lbs/week.

Input

Age 35, losing 1.5 lbs/week, protein 130g/day, resistance training 3x/week

Result

Risk Score: 22/100 (LOW). All factors well-managed. Continue current protocol.

Common Mistakes to Avoid

✕Relying on scale weight alone — the scale cannot distinguish fat loss from muscle loss without body composition measurement
✕Assuming cardio protects muscle as well as resistance training does (it does not)
✕Ignoring age as a risk factor — patients over 50 lose muscle proportionally faster during caloric restriction

Frequently Asked Questions

How much muscle do people lose on Ozempic or Wegovy?

DEXA scan data from the STEP trials shows approximately 25-40% of total weight lost is lean mass (muscle, bone, water). For example, if you lose 30 lbs total, 8-12 lbs may be lean mass. Resistance training and adequate protein can reduce this to 10-20% of total weight lost.

Can I build muscle while on GLP-1 medication?

Building new muscle while in a caloric deficit is difficult but not impossible, especially for beginners to resistance training. Most patients on GLP-1s should focus on preserving existing muscle through progressive resistance training 2-3x/week and consuming 1.6-2.2 g protein per kg of ideal body weight daily.

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