For those who think fasting is burning fat.

http://www.theglobeandmail.com/life/health-and-fitness/health/keen-to-try-a-fasting-diet-not-so-fast/article8461083/

""The catch

There’s one problem with the rationale behind fasting diets, according to David Lau, an obesity researcher, professor and chair of the diabetes and endocrine research group at the University of Calgary. When glycogen stores in the liver are depleted, the body doesn’t burn fat: It breaks down protein. Lau said starvation will only burn fat as fuel after about a week of starvation.

“Muscle protein breakdown occurs in the first 24 hours of starvation,” he said. “Muscle protein breakdown [is] not healthy.”

His concern is that many people are fasting without realizing they may be losing crucial muscle mass. The danger is that as protein in the body breaks down, it could lead to other unwanted side effects, such as altered immunity. In order to fight infections, the body needs to produce antibodies, a type of protein. But when the body is breaking down protein for fuel, it may not send the right signal to make antibodies, Lau said.

Britain’s National Health Service recently issued a warning to consumers about fasting diets, saying they simply haven’t been studied enough for anyone to conclude whether they are safe or effective. Although some studies have shown fasting diets appear to work, they typically involve a small number of patients or were conducted over a short time frame, meaning the results likely aren’t conclusive. People on fasting diets have also reported sleeping problems, irritability, bad breath, anxiety and fatigue during the day, according to the NHS."