For seven years, Dr. Ethan Weiss, a cardiologist at The University of California, San Francisco , has experimented with intermittent fasting. The health fad, which restricts eating to specific periods of your time , hit the mainstream after a series of promising studies in mice suggested that it’d be an efficient weight loss strategy in humans. So Weiss decided to offer it a try himself by restricting his own eating to eight hours per day. After seeing that he shed some pounds, many of his patients asked him whether it’d work for them. In 2018, he and a gaggle of researchers began a clinical test to review it. The results, published on Monday, surprised him.
The study found “no evidence” that time-restricted eating works as a weight loss strategy. People who were assigned to erode random times within a strict eight-hour window every day , skipping food within the morning, lost a mean of around 2 pounds over a 12 week-period. Subjects who ate at normal meal times, with snacks permitted, lost 1.5 pounds. The difference wasn’t “statistically significant,” consistent with the research team at UCSF. “I went into this hoping to demonstrate that this thing I’ve been doing for years works,” he said by phone. “But as soon as I saw the info , I stopped.”
Some evidence of muscle mass loss
Intermittent fasting, once a trend among self-styled “biohackers,” who use diet and lifestyle tweaks to undertake and improve their health, has become increasingly mainstream over the last decade. Instagram influencers regularly weigh in on the trend, and super-fit celebrities like Hugh Jackman have said it helps them get in shape for movie roles. In Silicon Valley , entrepreneur Kevin Rose launched an app called Zero to assist people monitor their fasts, noting that the scientific data “starts to urge pretty exciting.” Twitter CEO Jack Dorsey and therefore the actress Jennifer Aniston also rank among the famous fans. With numerous stars touting its benefits, in 2019, intermittent fasting was the top-trending diet search in Google, consistent with Google Trends data. But scientific evidence in humans remains thin. therefore the UCSF study, dubbed TREAT, led by Weiss and grad student Derek Lowe, aimed to fill a number of the gaps in research with a randomized controlled trial. Starting in 2018, they recruited 116 people that were overweight or obese. All the participants received a Bluetooth-connected scale, and were asked to exercise as they normally would.
Weiss suggests that the consequence may need caused both groups to lose weight: many of us can pay closer attention to what they eat when enrolled during a nutrition study, meaning they’re more likely to form healthier food choices. So going forward, he says, consumers should be increasingly skeptical about any nutrition study claiming weight loss benefits that doesn’t involve an impact group. There can also be a possible downside to intermittent fasting. A smaller percentage of participants were asked by the researchers to return on-site for more advanced testing, including changes in fat mass, lean mass, fasting glucose, fasting insulin then on. Through those measurements, researchers discovered people that engaged in time-restricted eating appeared to lose more muscle mass than the control group. Weiss says the result wasn’t definitive, but he’s hoping to conduct further studies down the road . There’s also a requirement for further studies to point out whether intermittent fasting is safe for people over 60, or those with chronic ailments like diabetes and on medications. Still, Weiss isn’t yet able to write off intermittent fasting entirely — there could also be benefits around fasts during different times of day. Weiss’ study had participants skip food within the morning. He didn’t study the consequences when it came to missing meals in the dark . But for now, he won’t be recommending it to his patients. “Just losing weight alone doesn’t mean goodies are happening for your health,” he explained.