Member-only story
A Brief History of Intermittent Fasting
A physician explains why time-restricted eating is nature’s anti-aging diet
No topic in the health sciences is more fundamental or more poorly understood than nutrition. How and what we eat now causes more disease and death than any other health risk factor. About half of all American adults have one or more preventable, diet-related chronic diseases.
Our norm of three meals a day with snacks between is antithetical to our biology. Recent research suggests a new paradigm with remarkable effects on aging, disease, and weight control.
It’s about time.
Caloric restriction (CR), a dramatic reduction in caloric intake without malnutrition, has been shown to not only reduce weight but prolong healthy life span in a variety of species from worms to nonhuman primates. Risk for cardiovascular disease, diabetes, and cancer, the leading causes of death and disability, are markedly diminished by CR regimens. However, few people can tolerate deprivation, and calorie restriction is also associated with undesirable side effects such as fatigue, loss of libido, impaired cold tolerance, and muscle wasting.
These obstacles drove a quest for a more user-friendly variation of CR. Valter Longo, at the University of Southern California (USC) Longevity Institute, was a pioneer in so-called fasting-mimicking diets. He demonstrated that five days of CR per month for three months caused beneficial changes in risk factors of age-related diseases in humans. Five days of CR, however, is still a tough ask for many — studies have shown that up to 30% of subjects attempting to comply with this regimen drop out.
A big breakthrough came in 2012. Satchidananda Panda at the Salk Institute for Biological Studies found that mice fed a high-fat diet eight hours per day were healthier and leaner than mice allowed to eat the same diet whenever they wanted, even though both groups consumed the same number of calories. The key variable appeared to be defining a daily time frame for feeding and fasting, hence the name — Time Restricted Feeding (TRF).
Panda then investigated this effect in humans under a variety of conditions that mimic the real world.
Our physiology is the…
