A diet that makes you thin and smart? Soon we could all be like Cindy Crawford (who is not only a model but also majored in chemical engineering). AFP PHOTO/ Indranil MUKHERJEE Source: AFP

According to the study, published today in the journal Cell Metabolism, following a four-day cycle of a low-calorie intake twice a month can lead to a reduction of belly fat and extended lifespan by increasing the number of progenitor and stem cells in various organs, including the brain, where it also found to boost learning and memory.

“Strict fasting is hard for people to stick to, and it can also be dangerous, so we developed a complex diet that triggers the same effects in the body,” says Valter Longo, a professor from the University of Southern California (USC), and director of the USC Longevity Institute in the USA, who led the study.

The new dietary approach, known as fasting mimicking diet (FMD), involved cutting down calories by up to 50% of normal intake and ingesting a specific combination of proteins, carbohydrates, fats and micronutrients for a few days every few months.

The total caloric intake was the same for mice used as controls compared to those that took part of the diet. This allowed researchers to ensure that the observed effects were not due to an overall dietary restriction.

Of mice, yeast and men

In the study, researchers tested the virtues of this new diet on yeast, mice and humans. Testing periodic fasting on yeast allowed researchers to better understand the inner working of fasting at a cellular level. Yeast treated with the diet had a longer lifespan and responded better to stress.

For the mice, this new fasting diet had the most surprising results, as it extended lifespan by 11%, rejuvenated blood components as well as the immune system, reduced some inflammatory diseases, reduced cancer incidence by half, slowed bone loss and improved cognitive abilities such as motor coordination, learning and balance.

The study also involved a pilot study on humans, which provided evidence this new diet may also work its magic in people. Participants who went through the diet for five days per month for a total of three months experienced benefits like decreased levels of glucose and of some hormones like IGF-I, a hormone involved in growth, but also associated with ageing and cancer susceptibility. They also experience a small reduction of body weight and significant reductions of risk factors associated with ageing, diabetes, heart disease and cancer.

Notably it reduced abdominal fat but not muscle mass and it also increased the levels of

circulating stem cells.

A promising future?

The outcome of this new diet, if confirmed to provide the same benefits in humans as in mice, could be a game changing health approach, as it would represent “the first safe and effective intervention to promote positive changes associated with longevity and health span”, says Longo. “[This diet] could be done by most people as infrequently as every 3-6 months and could play a central role in medicine. Not only in the treatment of a range of diseases but also in their prevention,” he adds.

“I believe this is arguably the first intervention which will target the ageing process itself by promoting cellular protection and regeneration/rejuvenation,” says Longo.

However, before you tighten your belt and start a fasting lifestyle you should check with your physician, as Longo notices that this diet may be good for everyone. For example, people suffering from diabetes, anorexia, or those in frail condition or very old should not follow this diet, says Longo. “The FMD can only be done under medical supervision and in people who are deemed to be fit enough to do it by a physician,” says Longo.

Also, you should probably wait until further clinical trials are completed and regulatory bodies such as the Food and Drug Administration (FDA) in the US grants approval.

Longo is now completing a larger study in humans to further confirm his results. “Then, we will sit down with FDA officers to pursue multiple disease treatment and prevention claims (cancer, diabetes and cardiovascular diseases),” he says.

The Fasting Mimicking Diet should become available in the next 6 months for worldwide use under medical supervision.

Michael Mosley's documentary that spawned the popular 5:2 Diet.