Intermittent fasting (IF) has become a popular way to lose weight. In one way, we’re all intermittent fasters—we don’t eat while we are sleeping. But the idea behind IF is that by extending the fasting part of your day, you’ll naturally eat less. Methods vary—some people eat during an eight-hour window and fast for 16 hours…others eat for 10 hours and fast for 14, etc. Proponents of IF say that the body undergoes metabolic changes that kick weight-loss into overdrive.
But: A study by researchers at Southern Medical University in Guangzhou, China, has cast doubt on IF—but their conclusion may be inaccurate. Problems with the study: It extended the fasting period by only about two hours—not a big enough difference to pick up the benefit. Plus, the amount of weight lost (or gained) by the participants was all over the map, a statistical concept called “variability.” The study’s variability was so high that, for its findings to achieve statistical significance, it would have needed at least three times as many participants.
Rather than no benefit, the study reported a nonstatistically significant weight loss of about 3.5 pounds on average across all the participants. But that’s right in line with prior research. If these results were incorporated into previous meta-analyses, they would show a modest to moderate but statistically significant loss of about 3.5 pounds (roughly 200 daily calories) for IF versus consuming equal calories through traditional dieting.
Conclusion: IF isn’t a silver bullet, but it does work for many people…and there are added benefits. Researchers have found positive associations between IF and insulin sensitivity, blood pressure, oxidative stress, fat-burning, cellular aging, mood and brain health. No study has found IF to be worse than traditional weight-loss methods, so there’s no reason not to give it a try.
