Is Fasting the New Fat-Busting Fad?

Weight loss through intermittent fasting has gained attention

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) It seems like weight loss trends change constantly – and there could be a new one on the horizon. However, with this new fad, the focus is not so much on what you eat, but on how long you don’t eat.

The new trend, called "intermittent fasting", focuses on shifting between periods of eating and periods of not eating, or fasting.

Supporters say that this diet protects the body against disease, increases lifespan and helps people cut out the excess calories.

"Talk to a dietitian before changing your diet."

According to CMAJ, the Canadian Medical Association Journal, “Some advocates recommend fasting every day for up to 16 hours and consuming food only during a short ‘eating window.’

Others suggest going without food once or twice a week for 24 hour periods — having dinner one night, for example, and skipping breakfast, lunch and snacks the next day, then eating a normal dinner (no gorging).”

Deborah Gordon, MD, nutrition and homeopathy expert, explained the theory behind fasting to dailyRx News.  

"When we fast, our body follows a fairly predictable pattern of 'alternate fuels', starting with the easiest target: our muscle stores of glycogen," explained Dr. Gordon.

How quickly fat begins to be burned varies widely from person to person, which could result in vastly different outcomes from fasting.

"If you are eating a low carbohydrate diet, or for other reasons have a low serum insulin, your body will happily, after about 8 hours, start to burn some fat – which is of course the goal of most dieters: fat loss is more important than weight loss," said Dr. Gordon.

"If, on the other hand, you have a high serum insulin (history of obesity, pre-diabetes, yo-yo dieting or just individual variation), your body is much more likely to burn fat very reluctantly, and turn to muscle consumption instead, leaving you weak, fatigued and hungry," she said.  

Not surprisingly, this fact has led to a fair share of skepticism about the intermittent fasting trend.

While it is not a huge controversy that many people need to cut down on the number of calories they consume, this method is relatively new to the field and has only small studies from which to draw conclusions. 

CMAJ expanded on the concerns some experts have expressed, including, “If one already has a diet poor in vitamins and protein, eating less food could lead to vitamin deficiency and muscle loss."

The verdict is still out on this new method, and in-depth research about intermittent fasting is likely to be explored further, especially if the fad continues to garner attention.

Dr. Gordon suggests that "...aspiring fasters check with their trusted medical advisor, as fasting can be quite beneficial and it can be, as the discussion points out, counterproductive."

Reviewed by: 
Review Date: 
March 21, 2013
Last Updated:
December 30, 2013