HALFTIME DIET

Half the pain of fasting, all of the benefits? Allison P. Davis tries Alternate Day Fasting, the one yo-yo diet that might actually be good for us

Call it a problem with authority, but being told I can’t eat something—even if it’s a self-imposed law—brings out my inner brat. Any decision I make to cut back instantly activates my instinct to gorge. I thought Weight Watchers’ built-in “cheat” points might be the answer, but I blew my first week’s allowance by Monday. I gave the “juice-fast till dinner” a shot—all the rage in Manhattan—and successfully detoxed all day, then went calorie crazy at night. At one point, I even devised my own plan, the “little bit” diet, which allowed me to indulge in tiny portions of whatever I wanted. But who can stop at one-eighth of a cheesesteak?

So fasting, the unlikely sounding fad diet du jour, seemed a no-way, no-how proposition—despite a glut of studies that has proven fasting doesn’t just help you lose weight, it also improves metabolism, lowers cholesterol, reduces the risk of cancer and heart disease, and slows the cognitive decline associated with Parkinson’s disease. It may even help us live longer by reducing levels of IGF-1, the growth hormone responsible for aging.

For a decade or so, scientists have been on a race to discover the most humane way to fast—the version that achieves maximum payoff with minimum misery. Alternate-day fasting (ADF), a sort of 50-50 approach, first came to light in a 2005 paper in The American Journal of Clinical Nutrition that proved that fasting even half the time could have serious benefits. Four years later, Krista Varady, PhD, a professor of nutrition at University of Illinois at Chicago, published a study of a somewhat more lenient ADF: Overweight subjects consumed an average diet (2,000 calories for women; 2,500 for men) on “feed” days, alternating with fast days during which they were allowed to eat 20 to 25 percent of that amount, in the form of a single low-fat meal. Bingo: Over eight weeks, the participants dropped 6 to 8 percent of their body weight.

Could there be an even less brutal version? On “Eat, Fast and Live Longer,” an episode of the BBC science program Horizon that aired last year, host Michael Mosley landed upon the “5:2 diet”: He ate normally five days a week, consumed 600 calories or fewer on the remaining two—and lost 14 pounds in six weeks. The Salk Institute for Biological Studies in San Diego tested a night-and-day variation: One group of mice was given 24-7 access to food, while another fed during the first eight hours of the day, then fasted from 5 P.M. to 9 A.M. Though both groups consumed the same amount, the nighttime fasters ended up thinner and healthier than those who ate around the clock.

Still, my interest was not piqued until Varady published a follow-up ADF study. This time, 17 subjects stuck to the original low-fat ADF diet, while 15 tried something new: a high-fat version. Instead of, say, Lean Cuisine lasagna, they ate a small portion of the real thing. Published last August in the journal Metabolism, the results were startling. Over eight weeks, both groups lost the same amount of weight—on average, 5.8 percent of their body mass. Those on the high-fat version were still eating less than usual on fast days, creating a calorie deficit. And because they were eating full-fat, they weren’t desperate to binge later. “We noticed some sort of satiety response,” says Varady. “The body begins to recognize when it’s really full.”

On the first day of my alternate-day fast, I woke to an emotional gut punch. No, I would not get to eat the warm, crusty everything bagel with cream cheese I’d craved through the night. I’d get one measly meal, and I wouldn’t even get that for four more hours. This fast, I thought, is not going to last.

Yet somehow it did. For four weeks, I split my days (and my social calendar) between 2,000-calorie feed days and 400- to 500-calorie “fast” days, usually consisting of a single lunchtime meal: soup or half a sandwich, a piece of fruit, and a cookie.

Nothing about fasting was easy. I was cranky, often tired. But on days when I couldn’t eat, it was a comfort just to know that at the stroke of midnight I could have whatever I wanted again. And it was freeing to stop counting calories and making trade-offs. I wasn’t swapping points or keeping a diary; I was simply eating.

But after a particularly horrendous feed-day brunch involving mimosas, a fried chicken sandwich, and a side of bacon, I phoned Varady’s colleague, PhD candidate Monica Klempel.

“This can’t be a diet!” I shrieked.

“Well, it sounds like you’re doing it right,” Klempel said. Fasting, she explained, plays a mind game of sorts: Most subjects in both of Varady’s ADF studies tended to think they were consuming more calories on feed days than they really were. Though that fried chicken sandwich had seemed unforgivably decadent, I’d eaten only half of it. This was occurring on most feed days: Once I got past initial cravings, the natural desire for fruits and vegetables took over. At the office cafeteria, I’d steer toward the sushi bar rather than the grill. And the scale crept down: I lost a pound and a half the first week; seven by the end of a month.

Still, I was also displaying the patterns of a binge eater, destroying a plate of nachos one day, struggling through deprivation the next. What about…balance? Dietician Carol Brunzell, RD, a representative of the American Academy of Nutrition and Dietetics, shares my skepticism. “Any kind of calorie deficit will result in losing weight,” Brunzell says. “But the million-dollar question is, What are you learning? How can you maintain this? I would suspect, and I hate to say this, you’ll just put the weight back on.”

But Varady, who is currently conducting the first yearlong study on the long-term sustainability of ADF, argues that people can—and do—stay on the diet long-term, and that the high-fat version makes it more feasible. “It’s really only having to diet half the time,” she says. “People can really stick to that.”

http://www.elle.com/beauty/health-fitness/alternate-day-fasting-diet