While research studies have shown that reducing our caloric intake by 20% to 40% could aid in weight loss and reduce health risks, given the array of appetising temptations in modern society, it is a struggle to eat less every day over a prolonged period.
A new study, by biochemist Valter Longo and his team from the University of Southern California takes dieters away from the conventional track of skipping meals to a less taxing fasting mimicking diet (FMD) that will prevent or treat illnesses like diabetes and cardiovascular disease.
In their randomised clinical trial, 71 people were put on the FMD diet for three months, while those in the control group kept their usual eating habits. For most of the month, participants ate as much of what they would usually take. For the five consecutive days, they followed a semi-fasting Pro Lon regimen, consuming 700 to 1100 calories a day.
In their previous study, Longo’s team reported that mice that were fed the rodent version of the diet lived longer and recorded lower blood sugar levels and fewer tumours. They also found that the regimen hastened the regeneration of the liver in the dieting rodents, rejuvenated certain cells in their blood, and increased the number of stem cells.
“We think that what the fasting mimicking diet does is rejuvenate,” Longo explains.
Results from the trial on humans have been promisingThe participants had lost an average of 2.6 kilos, showing lower levels of insulin-like growth factor and C-Reactive Protein. They also reported lower body mass index, trunk fat, waist circumference, blood pressure and cholesterol. The control group showed no changes, but when switched to the FMD, produced positive results.
“Dieting is often hard, but 75% of the participants managed to complete the trial,” says gerontologist Rafael de Cabo of the U.S. National Institute on Aging in Baltimore.
“But hard-core fasting, in which people drink only water for days at a time, may be no easier than calorie restriction. I’ve done it, and it was excruciating”, says Longo.
Though long-term trials have not been done on humans and this short-term trial of just three months cannot possibly conclude that the diet and longevity are correlated, Longo notes that the trial results may be attributed to the fact that fasting lowers levels of insulin-like growth factor or IGF-1, which is linked to cancer and diabetes. Lowering these hormones may slow cell growth and development and thus combats ageing and enhances health.
Longo’s follow-up trial hopes to test the diet on people who already have an age-related disease such as diabetes or are susceptible to one. He says enough research is behind the diet and he would recommend people try a partial fast like the one used in the trial, but it need not be done every month.
“For example, someone who is obese and who has high cholesterol and fasting glucose may need to consider doing it once a month whereas an athlete who eats a very healthy diet and is in perfect shape may only do it twice a year,” he explains.
Scientists divided on whether the new diet is practical“This single dietary change can counteract all these variables of ageing, and I think that’s very impressive,” says molecular biologist Christopher Hine of the Harvard School of Public Health in Boston.
According to gerontologist Rafael de Cabo of the U.S. National Institute on Aging, calorie restriction has failed miserably in human trials and this new regimen is achievable.
Research dietitian Michelle Harvie of the University Hospital of South Manchester in the United Kingdom hopes to see longer studies to confirm that the benefits persist and that people remain on the regimen.
“We need to help a lot of people, but what if only 2% of them are willing to do this?” she adds.
Nevertheless, as what biochemist James Mitchell from the Harvard School of Public health says, “The study shows that cutting calories all the time may not be necessary. Intermittent periods can have lasting effects.” MIMS
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