BY DANA G. SMITH
A friend of mine recently tried the 5:2 Diet—in which you consume 500 calories two days per week but eat normally the other five days. “It sucked,” she says. “I didn’t feel any mental clarity, I felt weak and confused. It was also awkward socially because you can’t really do anything on those days. You just want to go to sleep and have the day be over.”
But it probably made her healthier. While many diet or body-hacking fads are backed by dubious science at best (see coconut oil pulling), the trend of fasting to improve mental capacity and increase longevity—not to mention lose weight—is grounded in legitimate and fascinating scientific principles. The benefits of intermittent fasting or extreme calorie restriction range from improved insulin sensitivity to reduced inflammation to the growth of new brain cells.
Fasting is reported to shrink cancerous tumors, delay aging, and stave off the chronic diseases that accompany it, including heart disease, diabetes, and possibly even dementia.
But fasting is also really really hard. Even aging researcher and fasting expert Eric Verdin admitted that calorie restriction can be challenging and disruptive to domestic life.
“I never felt better than when I was on it, but it takes a lot of discipline, especially when you’re busy at work,” says Verdin, who is president and CEO of the Buck Institute for Research on Aging. “It’s also totally asocial. Everything is dictated by the diet. Living with a family and saying no to dinner is hard.”
Fortunately, as with any hot trend, companies have sprung up to make fasting easier or even unnecessary. And it’s becoming big business. Hundreds of diet and recipe books targeting everyone from beginners to body builders are available on Amazon. There’s even a subset of fasting literature aimed at devout Christians.
The first calorie-restriction meal delivery service also launched last year. Developed by gerontologist Valter Longo at the University of Southern California, the ProLon Fasting Mimicking Diet offers you five days’ worth of soups, teas, and bars totaling 800 daily calories for just $299.