For all those January dieters hoping to shed the holiday bulk, intermittent fasting, also known as IF, is all the rage.
The trend was sparked with the 5:2 diet, based on a book called "The Fast Diet" by journalists Dr. Michael Mosley and Mimi Spencer. The diet involves intermittent fasting throughout the week to shed stubborn bulge. You fast for two days of the week, but not completely -- you eat one-fourth of your typical daily calories, roughly 500 calories for women, 600 calories for men -- and eat what you desire the remaining five days. The rewards for your efforts are incredible weight loss and a reduced appetite, according to the diet's proponents. Other perks, they say, include living longer, looking younger, and even warding off dementia.
But now new diets have hit the scene, including the 4:3 diet, created by Dr. Krista Varady, who penned the diet book "Every Other Day," which involves fasting on alternate days.
According to The Independent in the U.K., the British Nutrition Foundation is hosting a symposium on intermittent fasting this week, noting that men seem particularly keen on trying the diets. Researchers from the University of Southern California are also studying how IT diets could affect weight and blood pressure.
A separate 2011 study, published in the International Journal of Obesity, compared IF diets against daily calorie restriction, with overweight women cutting their caloric intake by 20 per cent, the Los Angeles Times reports. One group reduced their calories every day, while a second group cut their calories by 75 per cent on two consecutive day a week, but ate normally on the other five days. After six months, both groups lost the same amount of weight, about 13 pounds, or nearly six kilos.
Some nutritionists are taking issues with the concept of fasting for a few days a week. For one, fasting can cause you to become overly focused on food, and then prompt overeating on your free-eating days, Heather Mangieri, a nutrition consultant and spokeswoman for the American Dietetic Association, told LiveScience. Plus people may opt for unhealthy foods on their non-fasting days, which could "potentially lead to nutrient deficiencies and poor eating habits," she said.