Intermittent fasting can produce rapid weight loss, prevent aging, and enhance longevity.
Research shows that people who do intermittent fasting lose weight more quickly and keep it off longer than those who follow conventional, linear diets where you're constantly depriving yourself. What's more, intermittent fasting has been shown to ward off diseases like cancer and dementia.
In intermittent fasting, you alternate between days of "fasting" (very low caloric intake) and days of "feasting." That's the idea behind the bestselling book, The 5:2 Diet.
Aside from weight loss, regularly experiencing hunger has many disease-fighting benefits, say researchers. "Wild animals don't often die of cancer and diseases of old age,'' said evolutionary biologist Dr. Margo Adler.
"They tend to die young as a result of environmental hazards and exposure to parasites. People might be able to reap some of the lifespan and anti-cancer benefits from dietary restriction."
Intermittent Fasting Protects the Brain and Slows Down Cellular Aging
While most people do intermittent fasting to lose weight, research from the National Institute on Aging (NIA) suggests that intermittent fasting can also improve brain functioning, and help maintain lean muscle mass.
"Just as exercise makes muscles stronger, fasting makes the brain stronger," Dr. Mark Mattson, chief of the NIA's neurosciences lab, told the Wall Street Journal. Mattson said the chemicals produced by fasting also appear to boost people's moods.
Mattson and his team conducted studies on animals with Alzheimer-like conditions, and found that alternating between days of fasting and normal eating seemed to slow or even reverse brain impairment. Intermittent fasting also helped the animals maintain their lean muscle mass even as they aged — the exact opposite of what happens to both animals and people as they get older.
Similar experiments conducted on humans (alternating between days of normal eating and calorie restriction) showed the same effects. Dr. Mattson said fasting for short periods of time like 16 to 24 hours induces a state of stress in the body, which responds by releasing neurotrophic proteins that stimulate neurons and other cells.
A major advantage of intermittent fasting is that it's easier to maintain than a linear diet where you're restricting yourself all the time. In the alternate-day fasting model, people ate whatever they wanted on non-fasting days and then ate a low-calorie diet (about 500 calories a day) on fasting days.
Intermittent fasting has skyrocketed in popularity, thanks to the runaway success of the Fast Diet (or 5:2 diet), which calls for fasting (500 calories a day) for two days of the week and eating whatever you want the other five days.
Another popular intermittent fasting diet is the Every Other Day Diet, where you alternate every other day between fasting and regular eating. Thousands of people say they lost dramatic amounts of weight quickly on both of these IF regimes.
Not only do most people lose weight quickly on these plans, but they say it's easier to stick to their diets. "We think that once the people get adjusted to the diet, it is easy to adhere to," said Dr. Mattson. "If you know that tomorrow you can eat normally, you can make it through today."