Following a diet that mimics fasting may reduce risk factors for disease in generally healthy people, according to a small study.
Dr. Min Wei of UCLA's Longevity Institute and colleagues tested the effects of the fasting-mimicking diet on various risk factors for diabetes, heart disease, cancer or other conditions.
The diet (FMD; brand name ProLon) is low in calories, sugars and protein but high in unsaturated fats. Forty-eight study participants ate normally for three months while 52 ate FMD for five days each month and ate normally the rest of the time. After three months, the groups switched regimens. Although all participants were considered healthy, some had high blood pressure, low levels of "good" cholesterol, and other risk factors.
A total of 71 people completed the study, which was published in Science Translational Medicine. Body mass index, blood pressure, blood sugar and cholesterol improved with FMD, but mainly for those who were already at risk. Side effects were mild, including fatigue, weakness and headaches.
Wei and Dr. Valter Longo of the University of California, San Diego, said in an interview published in the journal that while "the great majority" of participants had one or more risk factors for diseases such as diabetes, heart disease or cancer, "FDA trials will be necessary to demonstrate whether periodic FMD is effective in disease prevention and treatment."
Dr. Joseph Antoun, CEO of L-Nutra, Inc., which produces FMD, told Reuters Health by email that FMD "is intended for use by individuals who want to optimize their health and wellbeing, by overweight or obese individuals who want to manage their weight in an easy and healthy way, and by people who have abnormal levels of biomarkers for aging and age-related conditions."
That said, Antoun acknowledged that if you have common conditions associated with overweight and obesity such as diabetes, cardiovascular disease and cancer, you should not use FMD without a doctor's approval.
The product also should not be used by children under 18 or pregnant or nursing women. And it's not for you if you have certain metabolic diseases, liver or kidney disorders that may be affected by the very low glucose and protein content of the diet, or if you have nut or soy allergies. What's more, it "should never be combined with glucose-lowering drugs, such as metformin or insulin," according to Antoun.
Registered dietitian Ashlea Braun of the Ohio State University Wexner Medical Center in Columbus pointed out that researchers compared the fasting-mimicking diet to participants' usual diet. "Therefore, we don't yet know how this diet stands up against long-standing approaches already shown to be beneficial, such as the Mediterranean or DASH Diet."
"It's not clear if (FMD) enables individuals to consistently meet all micronutrient requirements," she told Reuters Health by email. "It's also not known how this type of restrictive diet affects muscle mass in the long term, and what impact this has on various indicators of health."
"Although there is some evidence showing these type of restrictive diets can help 'jump start' people considering lifestyle changes, more research is definitely needed before this is recommended for individuals," Braun concluded.