Occasional fasting has been linked to a variety of health benefits. Now a new study that examined the impact of time-restricted eating (TRE) on metabolic syndrome has suggested that it can be helpful to those at risk for diabetes, stroke and heart disease. Scientists completed a clinical trial involving people that have at least three of five characteristics: abdominal obesity, low levels of 'good' or HDL cholesterol, and high fasting blood sugar, blood pressure, and triglyceride levels; these factors can significantly increase the chance that more health problems will occur.
Reporting in Cell Metabolism, the clinical trial participants were found to lose weight and have improvements in their metabolic problems when their food consumption was restricted to a ten-hour period over twelve weeks. That will reduce their chances of getting diabetes or heart disease, or experiencing a stroke.
"There has been a lot of discussion about intermittent fasting and what time window people should eat within to get the benefits of this kind of diet," said the co-corresponding study author Satchidananda Panda, a Professor at the Salk Institute. "Based on what we've observed in mice, a 10-hour time window seems to convey these benefits. At the same time, it's not so restrictive that people can't follow it long-term."
The nineteen study volunteers were able to eat how much they wanted, at any time during a ten-hour window. Most of them were obese and the majority were taking some type of prescription drug. After the twelve weeks were up, they had lost an average of three percent of their weight, body mass index, and abdominal fat. Cholesterol levels and blood pressure went down in many participants, and fasting glucose levels had improved for a lot of them.
"We told people that they could choose when they ate their meals, as long as they remained within the 10-hour window," noted Panda. "We found that universally, they chose to eat breakfast later, about two hours after waking, and to eat dinner earlier, about three hours before going to bed." Around 70 percent of the volunteers were also getting better sleep, he added.
"As a preventive cardiologist, I try to work with my patients and encourage them to make lifestyle changes, but it is very hard to get them to make lasting and meaningful changes," said co-corresponding study author Pam Taub, a cardiologist and Associate Professor of Medicine at the University of California San Diego School of Medicine. "When someone has been diagnosed with metabolic syndrome, this is a critical window for intervention. Once people become diabetic or are on multiple medications such as insulin, it's very hard to reverse the disease process."
Many people in the study were able to reduce the medications they were taking and thought the plan was easier than a diet. A follow-up study has already started that will enroll 100 participants and take additional physiological measurements.
Taub recommends that anyone who is considering TRE should consult a doctor first, especially if they are using a prescription drug. "Any time someone is losing weight, they need to check with their doctor about whether their medications need to be adjusted," she explained. "For instance, if a patient is on blood pressure medications and they lose a significant amount of weight their blood pressure medication needs to be lowered."