{"id":29229,"date":"2026-07-20T13:45:00","date_gmt":"2026-07-20T18:45:00","guid":{"rendered":"https:\/\/okdiario.com\/metabolic\/en\/?p=29229"},"modified":"2026-07-20T12:21:00","modified_gmt":"2026-07-20T17:21:00","slug":"olympic-decathlete-kevin-mayer-says-the-best-diet-for-you-isnt-about-calories-its-about-something-written-in-your-genes","status":"publish","type":"post","link":"https:\/\/okdiario.com\/metabolic\/en\/health\/olympic-decathlete-kevin-mayer-says-the-best-diet-for-you-isnt-about-calories-its-about-something-written-in-your-genes-29229\/","title":{"rendered":"Olympic decathlete Kevin Mayer says the best diet for you isn’t about calories, it’s about something written in your genes"},"content":{"rendered":"\n

Can a family tree really tell an elite athlete what belongs on his plate? French decathlete Kevin Mayer, 34, said in a June 30, 2026, podcast interview that he becomes visibly leaner and feels fitter when he eats mainly meat and vegetables. <\/p>\n\n\n\n

He is a two-time world champion and the current world-record holder in the decathlon.<\/p>\n\n\n\n

That personal experience may be real for him. Current research,however, does not support using blond hair, blue eyes, or racial identity to determine what someone should eat. The evidence favors individual testing, training demands, health history, and a person\u2019s actual response to food.<\/p>\n\n\n\n

What he said<\/h2>\n\n\n\n

The athlete said he has tried many eating patterns and keeps returning to meat and vegetables<\/a>, even though he has ethical reservations about eating meat. In his account, the change in body composition and fitness is obvious whenever he follows that approach.<\/p>\n\n\n\n

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Read More: Doctors say you can get your intestines moving again without straining, since four everyday habits do more than any laxative could<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n

\u201cFor me, a blond person with blue eyes cannot eat exactly the same as a Black person or an Asian person,\u201d he said. He traced his family line to Vikings and argued that his ancestors would not have eaten rice, so his digestive system would be less suited to it.<\/p>\n\n\n\n

Those are two different claims. One describes a personal reaction to a diet, while the other turns that experience into a rule about large groups of people. That leap is where the science becomes shaky.<\/p>\n\n\n\n

Where ancestry can matter<\/h2>\n\n\n\n

Genes can influence nutrition in narrow, measurable ways. A classic example is lactase persistence<\/a>, the inherited ability to keep digesting the sugar in milk after childhood, which became more common in some populations with long histories of dairy farming. <\/p>\n\n\n\n

That is a specific biological trait, not a menu assigned by skin or hair color.<\/p>\n\n\n\n

The National Human Genome Research Institute says most human genetic variation occurs within population groups, not between them. It also says race and ethnicity are not reliable substitutes for genetic ancestry, while people with similar skin color can be genetically quite different. <\/p>\n\n\n\n

\"French
While Olympic decathlete Kevin Mayer attributes his success to diet choices based on ancestry, experts emphasize that nutritional needs are determined by individual biology and training demands.<\/figcaption><\/figure>\n\n\n\n

In other words, appearance is a poor shortcut for metabolism.<\/p>\n\n\n\n

Current evidence does not support using blond hair or blue eyes to decide whether a person can process rice. A genuine digestive problem would need to be investigated in that individual, not inferred from a family-history narrative. Simple labels are tempting, but the body is more complicated.<\/p>\n\n\n\n

Personalized diets have been tested<\/h2>\n\n\n\n

A large European experiment offers a useful reality check. Carlos Celis-Morales at Newcastle University helped lead the Food4Me randomized trial, which enrolled 1,607 adults in seven countries and followed them for six months.<\/p>\n\n\n\n

Participants received standard guidance or increasingly personalized nutrition advice.<\/p>\n\n\n\n

Tailored advice based on a person\u2019s existing diet improved eating habits more than general advice. Yet adding body measurements, blood markers, and five selected genetic variants did not make the program more effective. That extra genetic layer produced no clear additional benefit in the trial.<\/p>\n\n\n\n

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Read More: Just 5 grams of this black seed lowered bad cholesterol in eight weeks and blocked fat from building up, yet most people ignore it<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n

That does not mean genetics never matter. It means broad ancestry categories are far too blunt to prescribe breakfast, lunch, or dinner, while the evidence for DNA-based diet plans remains mixed. A family tree can raise a question, but it cannot answer it by itself.<\/p>\n\n\n\n

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