Layman: Protein Hype Is Overblown, Benefits Plateau
SkimNews Take
The public's overemphasis on protein, fueled by early research, now requires correction from the very experts whose work initially highlighted its benefits.
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- Donald Layman, a University of Illinois professor who has run more than 100 studies on the amino acid leucine, says protein's muscle-repair benefits plateau above 1.6 grams per kilogram of body weight per day, or at meals exceeding 60 grams of protein.
- US dietary guidelines recommend 1.2 to 1.6 grams of protein per kilogram of body weight daily, but roughly half of US adults fall short of that range, partly because of reliance on ultra-processed food.
- Layman distinguishes the Recommended Dietary Allowance of 0.8g/kg — the minimum to prevent deficiency — from the higher dietary guidelines target aimed at optimal health, warning consumers not to conflate the two numbers.
- Plant-based proteins are less concentrated and less bioavailable than animal proteins: chicken is nearly 100% absorbable, compared with roughly 75% for beans and under 60% for almonds, so vegans would need three cups of cooked beans or 200-plus almonds to match a 100-gram chicken breast's ~32 grams of protein.
- Layman warns that vegans who adopt the diet in their 20s and 30s may escape consequences at first, but fatigue and brittle hair and nails often surface in their 40s, especially if they pair a plant-based diet with a low-calorie one or a GLP-1 drug like semaglutide.
- For older adults whose appetite declines and whose bodies use protein less efficiently, Layman recommends a daily protein shake as an 'insurance policy' against muscle loss and the hip-fracture risk that follows falls.
Why it matters: Layman's guidance directly contradicts the marketing premise behind protein-fortified products flooding grocery shelves, and his warnings land on two fast-growing demographics — vegans and aging adults — at a moment when roughly half of US adults already fall short of optimal protein intake and GLP-1 drugs are suppressing appetites nationwide.
