A German study of time-restricted eating suggests that intermittent fasting may be effective for weight loss but does not deliver the broader cardiometabolic benefits many expect. The small study of 31 overweight or obese women found that participants who ate between 8 a.m. and 4 p.m. or between 1 p.m. and 9 p.m. for two weeks lost weight while maintaining their typical caloric intake, yet showed no improvement in blood glucose, blood pressure, cholesterol, or other key cardiovascular markers.
Published in Science Translational Medicine, the findings suggest that any cardiometabolic benefits attributed to intermittent fasting may simply result from eating fewer calories rather than meal timing itself. Participants did show a shift in their circadian rhythms, though the associated health impacts remain unknown.
Expert caution on study limitations
Several researchers cast doubt on the study’s significance due to its small sample size. Dr. Jason Fung noted the study was “severely underpowered to detect any difference, considering how gentle the intervention is.” He also observed that participants were fasting for 16 hours daily, longer than the typical 12 to 14 hours recommended.
Registered dietitian Lauren Harris-Pincus agreed that findings likely reflect the lack of intentional caloric restriction and reiterated the “quite small” sample size. She cautioned that restricting eating windows requires careful planning to ensure adequate intake of essential nutrients. She emphasized that skipping breakfast may result in lower intake of calcium, potassium, fiber, and vitamin D.
Dr. Daryl Gioffre noted the study did not account for critical factors like chronic stress, sleep quality, medications, hormone status, and baseline metabolic health—all of which can “significantly blunt fat loss and cardiometabolic improvements.” Researchers agreed more studies are needed to explore time-restricted eating’s effects over longer periods and in combination with intentional caloric restriction.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.foxnews.com/health/popular-intermittent-fasting-diets-may-not-deliver-health-benefits-many-expect