Fasting, the most extreme form of dietary restriction, has been shown to have multiple health benefits in many – but not all – animal models, but may not be a practical or safe long-term intervention for people. A team of researchers, led by scientists at the University of Southern California, studied the effects of a short-term fasting-like diet in mice and humans to determine potential health benefits.
Mice fed a low-calorie, low-protein fasting-mimicking diet (FMD) for 4 days twice a month and allowed to eat freely between FMD cycles experienced a number of health benefits. These included reduced cancer incidence, total fat, and inflammation. In addition, mice in the FMD group performed better on tests of short- and long-term memory, indicating that FMD may improve memory and cognition. On average, mice on FMD also lived 3 months (or approximately 11 percent) longer than mice in the control group.
To understand whether FMD may have the same advantages in humans as in mice, the researchers conducted a small, 3-month pilot study with 19 healthy volunteers in the intervention arm. Study participants followed a short-term FMD regimen, eating 1,100 kcal on day one, 725 kcal on days two through five, and their regular diet for the remainder of the month. After 3 months, researchers found participants on FMD had a 3 percent reduction in body weight and reduced risk factors for diabetes, heart disease, and cancer.
The researchers strongly cautioned that the FMD used in the pilot study was an experimental approach, requiring close and continuous medical supervision. More research is needed to determine the effects of FMD, particularly in the long-term.
Reference: Brandhorst, S., et al. A Periodic Diet that Mimics Fasting Promotes Multi-System Regeneration, Enhanced Cognitive Performance, and Healthspan. Cell Metabolism. July 7, 2015. doi:10.1016/j.cmet.2015.05.012