The stars were gifted a five-day dietary fasting-mimicking program.
Prolon provides dieters with bars, soups, drinks, and supplements said to deliver the benefits of intermittent fasting by using ingredients that “are not recognized as food by your body,” according to its website.
But more research is needed before experts can be sure it's beneficial, or even not harmful, long term. Plus, it's unsafe for certain populations, like people at risk for eating disorders.
Dr. Caroline Apovian, professor of medicine in endocrinology, diabetes, nutrition and weight management at Boston University School of Medicine, previously told Insider that the only studies done on fasting diets have been small.
“We are getting insight into early time restricted eating but there is no solid research there yet – it may be that a period of fasting during night hours is good for your metabolism – but studies are still coming,” Apovian said.