Fasting, including intermittent fasting, has been linked to many potential health benefits, including lower blood pressure, improved brain health, and similar. However, more controversy exists when it comes to fasting for weight loss, a controversy that has expanded with a new study published by the American Association for the Advancement of Science.
Dieting to lose weight
A typical diet for weight loss involves limiting the number of calories consumed in a day, forcing the body to burn some fat for energy. Doing this every day will result in weight loss — but sticking to such a protocol for a long period of time may be too hard for some dieters.
Intermittent fasting, which involves eating only during certain time periods or on certain days, is a popular alternative for those who find it hard to restrict during every meal. Rather than counting calories every day, many people will instead fast for one day, then eat regularly the next day, continuing to alternate their eating and fasting days in hopes of shedding weight.
According to the latest study, this method of weight loss isn’t as effective as traditional calorie-counting and may end up prolonging the amount of time it takes to lose weight.
Fasting vs. counting calories
The new study found that compared to restricting one’s calories every day, alternate-day intermittent fasting resulted in less weight and fat loss. The research involved 36 participants who were assigned to one of three diet groups for the duration of three weeks. One group followed a calorie-restricted alternate-day fasting diet, the second group followed a traditional daily calorie-restricted diet, and the third group did alternate-day fasting with no calorie restrictions.
By the end of the three weeks, the group sticking to the daily calorie-restricted diet experienced the most weight and fat loss with an average of 1.56kg. The calorie-restricted alternate-day fasting group had less average weight loss at .74kg, while the third group of unrestricted alternate-day fasters had no significant changes in weight.
Some factors may have influenced the lower weight results in the fasting group; the researchers note, for example, that these people were less active than before they started the diet. The study suggests that if someone does fast for weight loss, they should be mindful of getting enough activity during the diet to continue burning calories.
Not the first
This isn’t the first study that has found alternate-day fasting may not be a good way to pursue weight loss. In early March, a study from the University of Sydney found that this type of intermittent fasting may backfire if you’re trying to shed excess body fat.
According to the findings, eating every other day appears to prime the body to store extra calories as fat, something that may be the body’s way of preparing for the next time the person fasts. The researchers noted that visceral fat, which is located in the midsection around the organs, was particularly stubborn when faced with more than one alternate-day fasting session, essentially adapting so that it became more resistant to weight loss efforts.