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There’s Nothing Magical About Intermittent Fasting
New study shows time-restricted eating can cause weight loss, but no more than a healthy diet
In a blow to the latest dietary darling, a recent study found that people who practiced time-restricted eating (also known as intermittent fasting) didn’t experience any significant weight loss compared to a control group. The paper undermines one of the most popular and seemingly simplest diet and optimization fads of the past decade — eat whatever you want during a specific time window, and you’ll lose weight, achieve mental clarity, and simplify your life.
“It seemed like the ideal intervention,” says Ethan Weiss, MD, lead author of the new study and an associate professor at the University of California, San Francisco Cardiovascular Research Institute. “It was relatively easy to do, it didn’t require any fancy adherence to specific diets, it didn’t require calorie counting, it didn’t require you to track macros — just change the time you eat.”
The problem is, according to Weiss’s research, it doesn’t work.
The study was conducted in 116 people who were overweight or obese based on their BMI and wanted to lose weight. Half of the participants were instructed to eat three square meals a day but could snack in between (the control group), while the other half practiced the 16:8 time-restricted eating regimen, meaning they fasted for 16 hours a day and ate as much as they needed between 12:00 p.m. and 8:00 p.m. Both groups could eat whatever they wanted during the trial, the only thing that differed was the time at which they ate. At the end of the three-month study, the intermittent fasters lost an average of two pounds, while the control group lost roughly a pound and a half.
“There wasn’t really much weight loss at all,” says Weiss, who was a time-restricted eater himself before the results came out. “We were very surprised and, frankly, somewhat disappointed.”
