Doctor ‘Reversed’ His Age by 20, Shares 4 Diet Tips for Longevity

Cleveland Clinic/Getty Images

• Dr. Michael Roizen is 78 years old, but claims his “biological age” is 57.6.
• He’s the chief wellness officer at the Cleveland Clinic and follows his own advice for staying healthy.
• Dr. Roizen shared his dietary principles with Business Insider, including sticking to the Mediterranean diet.

A healthy aging expert who claims to have reversed his biological age by 20 years has shared his dietary principles with Business Insider.

Dr. Michael Roizen, an anesthesiologist and chief wellness officer at the Cleveland Clinic, is 78. But he told BI that his “biological age” is about 57.6, meaning that, given his risk of dying and/or developing age-related chronic diseases, his body appears decades younger. (It’s important to note that there’s no consensus on what biological age is or how to measure it.)

Roizen used the same principles that he says helped him stay young to develop a wellness institute at the Cleveland Clinic, offering employees financial incentives to make healthy lifestyle changes. The program has saved the Cleveland Clinic up to $200 million a year in health care costs for 101,000 employee patients since 2008, according to Roizen. and informed their research initiatives on healthy aging.

Here are the dietary principles followed by Roizen.

Adopt a Mediterranean diet

The Mediterranean diet consists primarily of whole foods such as fruits and vegetables, legumes, low-fat proteins, and dairy, and limits red meat, processed foods, and alcohol. It has been named the healthiest diet for seven years in a row by U.S. News & World Report, and research has linked it to better heart health, weight loss, and prevention of cognitive decline.

Trout and salmon are its main sources of animal protein, which contain vitamin D and omega-3 fatty acids.

Eat a big meal at lunch

Roizen eats his biggest meal at lunch and eats “very little” at dinner — usually just a salad. He can’t sleep well after a big meal and feels “much worse the next day.”

A 2024 study by researchers at the University of Alagoas in Brazil found that eating most of your calories at lunch could help prevent and treat obesity, regardless of the quality of the participant’s diet. Eating this way may better align with the body’s natural rhythms, the team suggested.

Limit calories five days a month

Roizen also follows the longevity diet developed by Valter Longo, a professor of gerontology and director of the University of Southern California Longevity Institute. He has been following it for seven years. The diet involves restricting calories five days a month to mimic the effects of fasting.

Calories are reduced to 1,100 on the first day of the “fast,” then to about 700 on days two through five. A 2024 study by Longo’s team at USC found that participants in the fasting-mimicking diet had an average biological age of two and a half years younger after three months on the diet.

David Clancy, who studies the biology of aging at Lancaster University in the U.K. and was not involved in the study, told BI at the time: “It’s not unreasonable to think that, at least between the ages of 40 and 60, this twice-a-year regimen could add three to four years of healthy life, perhaps more, in people with higher BMIs, blood pressure, blood sugar, etc.”

But he added that the scheme was “harsh” and workers might struggle to follow it. “It would be wise to schedule the fourth and fifth days as weekend days,” he said.

Eat within an eight-hour window

Roizen practices intermittent fasting, eating between 11 a.m. and 7 p.m. each day.

He said that while data on the impact of intermittent fasting The longevity data is much less robust than that for calorie-restricted fasting, but he said he liked the way he felt.

“At the end of that 16-hour period, I feel great and very energetic. I sleep a lot better and I feel like I have a lot more energy as well,” he said.

According to the journal BI, research on the potential benefits of intermittent fasting is inconclusive. One controversial study published earlier this year suggests that the diet may actually shorten people’s lifespans, while others suggest that it has no beneficial effects on our health.