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The Muscle Guard Score is the single number that tells you whether you are losing fat without losing muscle. It is the app's hero metric — the one number you check first, the one number that sits at the top of your Doctor PDF. It combines four inputs into a 0-to-100 score: protein adherence, resistance training frequency, weight trend, and body composition. This guide explains exactly how the Score is calculated, what a healthy trajectory looks like, and what to do when it stalls.
Why one number, not five
You can already see your weight on a scale, your protein in MyFitnessPal, your training in your gym log, and your measurements with a tape. The reason GLP-1 users come away from those tools feeling lost is that no single tool answers the question that matters: "Am I doing this properly?"
That question is composite. It requires you to weight protein against training against scale movement against body composition simultaneously. Humans aren't good at composite mental scoring; we anchor on the metric that moved most this week and miss the one that quietly drifted. The Muscle Guard Score does the weighting for you. One number, every morning, that captures the fat-loss-without-muscle-loss picture.
The four inputs and what each represents
| Input | Weight in Score | What "good" looks like |
|---|---|---|
| Protein adherence | 35% | 5+ days/week at 1.2-1.6 g/kg |
| Resistance training frequency | 25% | 2-4 sessions/week, all major groups |
| Weight trend | 20% | 0.5-1.0% body weight loss per week |
| Body composition (waist, hip, body-fat estimate) | 20% | Waist down faster than weight; lean mass stable or rising |
Weights reflect the relative contribution to muscle preservation evidence. Adjustments may follow as more data accrues — current weights frozen Q1 2026.
How the Score is calculated
Each input is normalised to a 0-100 sub-score. Protein adherence is the rolling 7-day average of (daily protein / your personal target), capped at 100. Training frequency is the rolling 14-day count against target. Weight trend is a 14-day rolling rate compared against your prescriber-set or app-default healthy range. Body composition is the 30-day direction of travel — are measurements moving in a fat-loss-without-muscle-loss pattern?
Each sub-score is then weighted as above and summed. The output is a 0-100 number, with rough bands: 0-49 "needs attention", 50-69 "okay", 70-84 "on track", 85+ "excellent". The bands are diagnostic, not graded — the goal is consistency in the 70+ range, not chasing 100.
What a healthy trajectory looks like
The first eight weeks on a GLP-1 are usually scored lower than the user expects. Appetite suppression is hitting hard, food blankness is real, and training feels worse. A Score in the 50-65 range during weeks 1-4 is normal — not a problem, just the body adjusting. The Personal Coach typically reads this pattern and dampens the protein push during the worst nausea weeks.
From week 8-10 onwards, a healthy trajectory takes the Score into the 70s and holds it there. Plateaus in weight don't necessarily drop the Score, because protein adherence and training are weighted higher. A flat-scale week with strong protein and three training sessions reads as a healthy plateau, not a problem. A weight-loss week with low protein and missed training reads as a problem hiding behind a number on the scale.
What to do when your Score stalls
Stalls usually fall into one of three patterns:
- Protein dropping. The most common stall driver. Re-anchor breakfast protein (the meal most often skipped on a GLP-1). Use the AI plate scan to spot-check current intake against target.
- Training missed for two weeks. The Score weighting on the rolling 14-day window will catch this fast. Restart at lighter weight and rebuild — consistency over intensity for the first two weeks back.
- Weight stalled but body composition slipping. The hardest stall to read on the scale alone. The Score will catch it because the body composition sub-score moves independently. Action: more protein, more resistance, less cardio if cardio is excessive.
The Personal Coach reads these patterns and offers a specific nudge. The Doctor PDF presents the Score and its sub-scores in the layout that makes the conversation with your prescriber productive.
Limitations of any composite score
One number cannot capture the whole picture. Two limits worth knowing about. First, the body composition sub-score is built on tape-and-scale measurements; DEXA gives more precise data and a DEXA reading every 12 weeks is a useful sanity check (see the body recomp guide for the DEXA cadence). Second, the Score is designed for the active weight-loss phase. In maintenance the weighting shifts — protein and training matter more, weight movement matters less. The maintenance-mode version of the Score launches alongside the maintenance feature later in 2026. See the maintenance guide for the broader picture.
Frequently asked questions
What's a good Muscle Guard Score?
Anything in the 70-84 range is on track. 85+ is excellent. Below 50 is a signal that protein, training, or both need attention. Don't chase 100 — chase consistency.
Why is protein weighted higher than weight loss?
Because the evidence is strongest that protein intake is what protects lean mass on a GLP-1. Weight loss happens on a GLP-1 almost automatically; muscle preservation is what you have to work for.
Does the Score change for women vs men?
The methodology is the same, but the protein target adjusts to your body weight automatically. A 60 kg user targets 72-96 g/day; a 90 kg user targets 108-144 g/day.
My weight stalled but my Score went up — why?
Because protein and training have caught up. The Score reads a flat-scale week with strong protein and consistent training as a healthy plateau, not a problem.
Is the Score visible to my doctor?
Yes. The Doctor PDF shows your current Score, the 12-week trend line, and the four sub-scores. It's the first thing your prescriber sees on page one.
Can I see the historic Score?
Yes. Trends, rolling averages, and side-by-side with shot day and weight measurements. The Personal Coach reads the trend and surfaces the stall before you do.
Does the Score work in maintenance mode?
A maintenance-mode version of the Score launches alongside the maintenance feature later in 2026 — weighted differently, with protein and training higher and weight movement lower.
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