Thirty years ago, when I began studying protein metabolism, I would never have guessed that 2025 would be spent explaining why more protein is not always better.

Protein was once the quiet macronutrient that was always assumed sufficient. Carbs had their era, and fat had its moment in the sun. Protein arrived late, but I welcomed the attention.

The phrase “jumped the shark” comes from a now-infamous 1977 episode of the iconic sitcom Happy Days, when the character Fonzie (Henry Winkler) literally water-skied over a shark. It was the moment the show sacrificed solid plot and logic for spectacle. In 2025, dietary protein repeated Winkler’s performance and crossed the line from evidence-based nutrition into performance theatre.

In 2025, protein became a metabolic Jack-of-all nutrients: protein for fat loss, protein for longevity, protein for weight loss, protein for hormone balance, protein for menopause, protein for people on GLP-1 drugs, protein for people who exercise, protein for people who do not. Protein everywhere, and the more, the better.

Despite a number of prominent voices promoting very high protein intakes in 2025, the reality is that the research data hadn’t changed. It was the messaging and volume that had been turned up.

One reason protein is so easy to overhype is that its effects are real, but conditional. Protein supports muscle function and adaptation, but it does not act in isolation.

I use analogies because they capture biology surprisingly well. Protein does not bake the cake; exercise does. Protein is the (thin) layer of icing (or the sprinkles on the icing). Once the cake is properly iced, adding more icing........

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