'Fasting' diet can help you stay sharp and slim

If you find it hard to stick to strict fasting, don't worry. Following for just five days in three months a diet that mimics fasting can help you lose fat, get smarter and live longer, says a study.

The three-tiered study on periodic fasting's effects -- testing yeast, mice and humans -- was published in the journal Cell Metabolism.

Cycles of a four-day low-calorie diet that mimics fasting (FMD) cut visceral belly fat and elevated the number of progenitor and stem cells in several organs of old mice -- including the brain, where it boosted neural regeneration and improved learning and memory.

A pilot study in humans found evidence that the mouse study was applicable to humans.

In the pilot human trial, three cycles of a similar diet given to 19 participants once a month for five days decreased risk factors and biomarkers for ageing, diabetes, cardiovascular disease and cancer with no major adverse side effects, said study author Valter Longo, professor at University of Southern California Davis School of Gerontology in the US.

"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," Longo said.

The diet slashed the individual's caloric intake down to 34 to 54 percent of normal, with a specific composition of proteins, carbohydrates, fats and micronutrients.

It decreased amounts of the hormone IGFBP-I, which is required during development to grow, but it is a promoter of ageing and has been linked to cancer susceptibility.

It also increased the amount of the hormone IGFBP and reduced biomarkers/risk factors linked to diabetes and cardiovascular disease, including glucose, trunk fat and C-reactive protein without negatively affecting muscle and bone mass.

"It's about reprogramming the body so it enters a slower ageing mode, but also rejuvenating it through stem cell-based regeneration."

For 25 days a month, study participants went back to their regular eating habits -- good or bad -- once they finished the treatment.

They were not asked to change their diet and still saw positive changes, the study said.

Longo believes that for most normal people, the FMD can be done every three to six months, depending on the abdominal circumference and health status.