This past week, CNN reported that three men with Type 2 diabetes used intermittent fasting to reverse their dependence on insulin. “The new case report says the three patients also lost weight, and their HbA1Cs, a measure of blood sugar levels, improved,” reported CNN.
Chances are, if you’ve been paying any attention to current diet trends, you’ve heard of intermittent fasting because, per several headlines, it’s the new cool way to starve yourself in the name of health, happiness and a skinnier waistline.
But like, what is it exactly?
According to Healthline, intermittent fasting is an eating pattern that cycles between periods of fasting and eating. Which is why intermittent fasting is less a diet per se and more accurately described as an eating pattern, since it doesn’t specify which foods you should or shouldn’t eat, but instead focuses on when you should eat them.
If you’re worried that this all sounds like some new diet trend that’s going to be deemed as unhealthy after a few years and several more studies, think again: Fasting is actually one of the most ancient and widespread healing traditions out there.
“Hippocrates of Cos (c 460 – c370 BC) is widely considered the father of modern medicine. Among the treatments that he prescribed and championed was the practice of fasting, and the consumption of apple cider vinegar. Hippocrates wrote, ‘To eat when you are sick, is to feed your illness.’ The ancient Greek writer and historian Plutarch (cAD46 – c AD 120) also echoed these sentiments. He wrote, ‘Instead of using medicine, better fast today,’” reports Intensive Dietary Management.
Okay, so far, so good. But let’s get down to brass tacks: How many non-stuffing my face hours are we talking about?
The same Healthline article suggests that common intermittent fasting methods involve daily 16-hour fasts or fasting for 24 hours, twice a week. “Also called the Leangains protocol, it involves skipping breakfast and restricting your daily eating period to 8 hours, such as 1 to 9 p.m. Then you fast for 16 hours in between,” reports Healthline. Dorothy Sears, the associate director of the Center for Circadian Biology at the University of California, San Diego, told The Cut that she suggests trying a longer, more sustainable eating window. “Instead, Sears suggests a 14/10 fasting-to-eating ratio—meaning you’d eat over a ten-hour period (say, between the hours of 8 a.m. and 6 p.m.), and fast the rest of the time, for example,” reports The Cut.
Can I at least drink water during my fasting hours?
Yes—you can also have coffee and tea, according to this LiveStrong article. But you can’t add sugar, cream, milk or anything else that might spike your insulin levels or mess with your blood sugar.
This seems pretty doable, but what’s the point, exactly? Am I going to lose weight or live longer or what?
Dana Hunnes, senior dietitian at the Ronald Reagan UCLA Medical Center, thinks so. “There are animal studies that suggest that intermittent fasting, or decreasing calories in general, can prolong the life of the research animal (in this case I believe it’s rats and/or monkeys) by lowering inflammation and lowering insulin-like growth factors which age us,” says Hunnes.
Additionally, articles in Harvard Health, Time, Health.com, Shape.com and Scientific American all agree with Hunnes that the majority of information on intermittent fasting seems to suggest that it’s a good approach to living a healthier lifestyle. “There continues to be good evidence that intermittent fasting is producing weight-loss benefits, and we also have some evidence that these diets can reduce inflammation, they can reduce blood pressure and resting heart rate, and they seem to have beneficial effects on the cardiovascular system,” Benjamin Horne, director of cardiovascular and genetic epidemiology at Utah’s non-profit Intermountain Healthcare system, told Time earlier this year.
Still, Hunnes points out that there’s also research that indicates that eating a low animal-protein diet, meaning a primarily plant-based diet, regardless of calorie restriction, can accomplish the same goals. “So, while intermittent fasting might work for some people, I don’t typically recommend it because it can be hard to do with food messaging all around us all the time,” she says.
If this has been around forever, why am I just hearing about it now?
One reason is because most of the conclusive research done on intermittent fasting thus far has been on mice. According to the same article in The Cut, there are only 17 studies done on intermittent fasting in humans (not including the one mentioned above), and most haven’t had a large sample size. Another reason is because it’s the new celebrity diet du jour.
“It has been promoted in best-selling books and endorsed by celebrities like the actors Hugh Jackman and Benedict Cumberbatch. The late-night talk show host Jimmy Kimmel claims that for the past two years he has followed an intermittent fasting program known as the 5:2 diet, which entails normal eating for five days and fasting for two—a practice Mr. Kimmel credits for his significant weight loss,” reports The New York Times.
Important question: When you say I can eat whatever I want during those 8 to 10 hours, do you really mean anything?
Unfortunately, no. “It is not possible to binge on junk foods during the eating periods and expect to lose weight and improve health, reports a different Healthline article. “Calories still count, and food quality is still absolutely crucial.” Hunnes agrees: “If you’re eating a stick of butter and brownies, probably not,” she says. “If you’re eating whole-grains, fruits, vegetables and are generally eating fewer calories than otherwise, yes.”