Protein

Arnold Schwarzenegger said“Eat enough protein and keep lifting, and you hold on to your muscle as you age.”

The science saysStrongly supported. Protein plus resistance training is one of the best-proven ways to protect aging muscle.

Verdict: Real, and worth copying.

Sylvester Stallone said“Hard training, high protein, and growth hormone keep you strong past forty.”

The science saysHalf right. Lifting and protein genuinely preserve aging muscle, but the growth hormone he credits is unproven for anti-aging and carries real risks.

Verdict: The barbell earned the physique. The growth hormone is renting it back.

Dwayne Johnson said“Thousands of calories and big cheat meals fuel this physique.”

The science saysMostly fuel, not magic. Protein helps muscle only up to a point; the rest is energy for elite training, and the cheat-meal-as-engine idea is untested.

Verdict: Eat like a mountain only if you train like one.

Paul McCartney said“McCartney says that beyond his ethical reasons, a health argument entered the picture once he heard that eating a lot of red meat isn't good for you.”

The science saysCohort studies link high red and especially processed meat intake to modestly higher mortality, though the certainty for unprocessed red meat is low.

Verdict: Cutting back on red meat, processed meat most of all, is a reasonable bet, but the size of the personal benefit is modest and uncertain.

Lenny Kravitz said“Kravitz says the muscle he carries at 62 was built with training and food alone, without peptides, growth hormone, or testosterone, and that the drug-free route is harder but fully attainable.”

The science saysResistance training reliably builds and preserves muscle and strength well into later life, so the habit behind the claim is on genuinely solid ground, even though no outside party can audit whether any individual is actually drug-free.

Verdict: The training science is about as settled as it gets: the 'all natural' half is a claim only he can audit.

Erling Haaland said“Haaland says milk, specifically the raw unpasteurised milk he buys direct from a farm, is a superfood that benefits his stomach, skin, bones and muscles.”

The science saysMilk is a genuinely useful source of protein, calcium and iodine, but the raw and unpasteurised element adds documented infection risk without a demonstrated nutritional advantage.

Verdict: The milk earns its keep; the word raw is the part the evidence does not pay for.

Lewis Hamilton said“Hamilton says switching to a fully plant-based diet made him feel physically better than at any point in his life, with higher energy, more strength in the gym, and no bloating.”

The science saysWell-planned plant-based diets are reliably linked to better cholesterol and lower cardiovascular risk, but the specific claims about energy, strength and skin are personal impressions rather than tested outcomes.

Verdict: The heart numbers hold up better than the mirror does.

Bryson DeChambeau said“DeChambeau bulked up on six to seven protein shakes a day to add driving distance, and has since said the way he was eating was improper and left him feeling unwell.”

The science saysProtein supplementation reliably improves muscle and strength gains alongside resistance training, but the measurable benefit plateaus at around 1.6 grams per kilogram of body weight a day, well below what this approach involved.

Verdict: The training built the driver swing; the seventh shake was along for the ride.

Dan Buettner said“Buettner says the single biggest longevity move available to most people is learning to cook a whole-food, plant-based diet at home, which he estimates is worth six to ten extra years.”

The science saysThe direction of the advice matches large diet-and-mortality datasets, but the specific six-to-ten-year figure comes from computer modeling of observational data, not from anyone actually living longer in a trial.

Verdict: Right direction, borrowed precision: the years are a simulation, not a stopwatch.

David Attenborough said“Attenborough says he has quietly shifted away from red meat toward a largely vegetarian diet that still includes fish and cheese.”

The science saysDirectionally supported but not strongly: large cohort studies consistently associate lower red and processed meat intake with somewhat lower all-cause mortality, though the certainty of that evidence has been formally judged low.

Verdict: A modest, real-looking benefit that the headlines have consistently oversold in both directions.

Carl Lewis said“Lewis says his strongest season of competition came in the first year he ate a vegan diet, and that the diet has kept his weight in check since.”

The science saysWell planned vegan diets can support high-level athletic performance, but the research does not show they improve it.

Verdict: A real result from a real athlete, but one season is a story, not a finding.

Lizzo said“Lizzo says her body change came from circuit style weight training plus eating in a calorie deficit, not from a medication.”

The science saysCombining resistance training with a modest calorie deficit is the best evidenced way to lose fat while limiting the muscle lost along with it.

Verdict: The unglamorous method that the trials actually back, described accurately.