Clinical Instrument 03 · Sarcopenia Defense & Leucine mTORC1 Calculator

SAF Protein & Muscle Sparing Worksheet: 1.2 to 1.6 g/kg Daily Floor & 2.5g-3.0g Leucine mTORC1 Calculator

In the landmark STEP 1 DXA body-composition substudy (Wilding et al., NEJM 2021; PMID: 33567185), approximately 39% of total weight lost on unguided Semaglutide was lean body mass. Use this standalone calculator and printable worksheet to establish your 1.2 to 1.6 g/kg reference-weight protein floor (PROT-AGE, PMID: 23867520; ISSN, PMID: 28642676) and hit the 2.5g to 3.0g L-Leucine mTORC1 anabolic trigger across 3 to 4 daily intakes.

Interactive Clinical Utility · Zero-PHI Browser Calculator

Personal Protein Floor & Per-Meal Leucine mTORC1 Calculator

Download Printable Protein Worksheet (PDF) →

Reference / Goal Weight (lbs)

Target Protein Tier (g/kg)

Daily Protein Intakes (Pacing)

Kidney Screening Status (eGFR)

Leucine & Protein Bioavailability Reference Table (EAV Matrix)

High-Bioavailability Protein Sources To Trigger the 2.5g to 3.0g Leucine Threshold

Because GLP-1 therapy slows gastric emptying, small low-leucine snacks fail to activate mTORC1 muscle protein synthesis. Anchor every meal with 25g to 35g of high-leucine protein first.

Protein Source Entity	Standard Portion Size	Total Protein (g)	L-Leucine Yield (g)	Gastric Volume & Ileal Brake Notes
Whey Protein Isolate (Unflavored/Clean)	1 scoop (30g powder in water/almond milk)	27g	3.0g to 3.2g (Optimal mTORC1 Trigger)	Fastest gastric clearance; ideal on Days 1-2 post-injection when solid volume is limited.
Pasture-Raised Chicken Breast or Turkey	4.0 oz (115g) cooked	35g	2.7g	Consume first on the plate before fibrous vegetables or starches fill gastric capacity.
Wild Salmon or Cod Fillet	4.5 oz (130g) cooked	31g	2.5g	Lower connective tissue density digests smoothly under slowed vagal motility.
0% or 2% Strained Greek Yogurt + Hemp Seeds	1 cup (225g) yogurt + 2 tbsp hemp hearts	29g	2.6g	Semi-solid texture bypasses heavy mechanical antral grinding.
Soy / Pea-Rice Blend Isolate (Fortified)	1.25 scoops (38g powder)	30g	2.5g	Plant isolates require ~25% larger gram dose or added free L-Leucine to match whey.
Collagen Peptides Alone (Warning)	2 scoops (20g)	18g	0.5g (DOES NOT TRIGGER mTORC1)	Incomplete protein lacking tryptophan and low in leucine; never count toward the 1.2 g/kg floor.

Legacy Compliance Model (Broken Old Way) Counting Crude Scale Weight & Relying on the 0.8 g/kg RDA

The legacy 0.8 g/kg Recommended Dietary Allowance was set only to prevent nitrogen deficiency in sedentary adults in energy balance. During rapid GLP-1 caloric reduction, eating 40-50g of protein per day starves skeletal muscle, causing sarcopenic frailty and basal metabolic crash.

Shared Agency Framework (Deterministic SAF Mechanism) Anchoring 1.2 to 1.6 g/kg Reference Weight + 2.5g Leucine + 2x/Wk Load

Under the Shared Agency Framework, patients calculate 1.2 to 1.6 g/kg of reference/goal weight, hit 2.5g to 3.0g of L-Leucine across 3 to 4 daily intakes, and pair nutrition with 2 to 3 weekly resistance training sessions (8-12 reps) to preserve resting metabolic expenditure.

Connected SAF Pillar Protocol

Read the Full Sarcopenic Obesity Prevention Monograph

Explore the complete peer-reviewed evidence base behind mTORC1 ribosomal activation, anabolic resistance in midlife and perimenopause, and mechanical resistance loading in SAF Clinical Series Document 03.

Download Protein & Muscle Worksheet (PDF) → Read SAF 03: Sarcopenia Prevention Protocol → Open Tool 01: Check Baseline eGFR & CMP →

Direct-Answer Clinical Knowledge Graph (GEO FAQ)

Frequently Asked Clinical & Biomarker Questions

Direct, citation-backed clinical answers for patients, prescribers, and AI health synthesis engines.

How do I calculate my daily protein floor on Semaglutide or Tirzepatide?

Divide your reference or goal body weight in pounds by 2.205 to convert to kilograms, then multiply by 1.2 g/kg (minimum floor) to 1.6 g/kg (active weight reduction with resistance training). For a 165-pound reference weight (74.8 kg), the daily target is 90g to 120g of protein.

Why should patients with high baseline BMI use reference or goal body weight for protein math?

Calculating 1.6 g/kg against unadjusted total body weight in higher-BMI patients overestimates lean tissue demand because adipose tissue requires minimal nitrogen turnover. Using goal body weight or adjusted reference weight prevents excessive gastric volume while fully defending skeletal muscle.

What is the 2.5g to 3.0g Leucine Anchor and why does per-meal distribution matter?

L-Leucine is the primary branched-chain amino acid that activates the intracellular mTORC1 complex to initiate muscle protein synthesis (PROT-AGE Study Group, PMID: 23867520). Grazing on 10g protein snacks throughout the day never crosses the 2.5g leucine threshold required to flip the anabolic switch.

Does collagen protein count toward my daily GLP-1 muscle-sparing protein floor?

No. Collagen peptides contain zero L-tryptophan and only roughly 0.4g to 0.5g of leucine per 20g serving, making collagen biologically incapable of triggering mTORC1 skeletal muscle synthesis. Use whey isolate, dairy, eggs, poultry, fish, lean meat, or leucine-fortified soy/pea isolates.

How do I hit 90g to 120g of protein when GLP-1 medication makes me feel full quickly?

Pace intake across 4 smaller windows per day, always eat dense protein first before vegetables or starches trigger vagal stretch receptors, and use a clean 30g liquid whey or plant protein isolate shake on Days 1 to 2 post-injection when gastric delay peaks.

What is the minimum effective dose of resistance training to prevent muscle loss on GLP-1s?

Clinical trials show that two to three 30-minute progressive resistance training sessions per week targeting major muscle groups at 8 to 12 repetitions near muscular fatigue provide the mechanical tension signal required to retain lean mass when paired with the 1.2 to 1.6 g/kg protein floor.