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About the GLP-1 Protein Floor

What this calculator answers

GLP-1 medications (semaglutide, tirzepatide, and related drugs) cause rapid weight loss largely by suppressing appetite. The unintended consequence: many users do not eat enough protein and lose meaningful lean body mass alongside the fat. Clinical guidelines now recommend a higher protein floor while on these medications to preserve muscle. This tool calculates that floor based on your current weight and target.

How the math works

The general recommendation for adults losing weight on GLP-1 therapy is 1.2 to 1.6 grams of protein per kilogram of body weight per day, with the higher end of that range for older adults or those losing weight quickly. The tool converts your weight to kilograms, multiplies by your chosen protein ratio, and returns the daily protein floor in grams. It also estimates the number of high-protein servings (chicken, fish, dairy, legumes) needed to hit that floor.

When to use it

  • You just started a GLP-1 medication and want a concrete daily protein target before appetite suppression hits.
  • Your dosage just increased and your appetite dropped further; you want to recalibrate your protein goal.
  • You are tracking strength or body composition during weight loss and want to confirm your intake is high enough to preserve muscle.
  • You are an older adult (over 60) on a GLP-1 and concerned about sarcopenia (age-related muscle loss).

Common mistakes

  • Aiming for the lower end of the range without medical supervision. For most adults losing weight on GLP-1s, 1.4 to 1.6 grams per kilogram is safer than 1.2.
  • Counting plant-based protein the same as animal protein. Plant proteins generally have lower digestibility and amino acid completeness; you may need 10 to 25 percent more to match.
  • Forgetting that protein needs are based on current body weight, not goal weight. Recalculate periodically as you lose.
  • Treating the floor as a ceiling. Going over the protein floor is fine for most healthy adults; falling short of it is the actual risk.

A worked example

A 200 pound (90.7 kg) adult on a GLP-1 with a 1.4 gram per kilogram target needs 127 grams of protein per day. That is roughly equivalent to a 6-ounce chicken breast (50 grams), a 5-ounce serving of Greek yogurt (15 grams), two eggs (12 grams), a protein shake (25 grams), and a 4-ounce serving of salmon (25 grams). At 1.6 grams per kilogram, the same person needs 145 grams per day, requiring one additional serving.

Frequently asked questions

Is this medical advice?

No. This tool calculates a general planning target based on published nutrition research. Always work with your prescribing physician or a registered dietitian for personalized guidance.

What if I cannot physically eat that much protein due to appetite suppression?

Liquid protein (whey, casein, plant-based isolates) and high-protein dairy are easier to consume than solid meat. A protein shake plus Greek yogurt can deliver 50 grams without much volume.

Should I also count protein from carbs and grains?

Yes. Bread, oats, rice, and beans all contribute. The total daily intake is what matters, not just the meat portion.

Does protein timing matter?

Yes, modestly. Spreading protein roughly evenly across three to four meals (rather than one large dinner) appears to support muscle protein synthesis better, especially in older adults.

What about strength training?

Resistance training is the single most important behavior for preserving muscle during weight loss, GLP-1 or otherwise. Protein only matters if there is a stimulus for the muscle to maintain itself.

This page is for general educational information only. It is not financial, tax, legal, or medical advice. Consult a qualified professional before making decisions based on this tool.