Intermittent fasting with or without carbohydrate restriction, effective treatment of metabolic syndrome

Overconsumption of carbohydrate-rich food and negative eating patterns increase the risk of metabolic syndrome. The first line of therapy for metabolic syndrome (MetS) is lifestyle interventions for reducing body weight. However, long-term adherence to lifestyle intervention remains challenging. Among dietary interventions, a low-carbohydrate diet is more appropriate for weight loss in overweight people than a low-fat diet.

Apart from a low-carbohydrate diet, time-restricted eating has gained popularity in recent years for causing significant weight reduction. TRE is defined as limiting meals to a specific time and fasting (tea and water without sugar or artificial sweeteners) for the remainder of the day.

Against the above background, a research team led by Mingqian He, The First Affiliated Hospital of Xi'an JiaoTong University, Shaanxi, P.R. China, conducted a randomized trial to examine the effects of a low-carbohydrate diet, 8-h time-restricted eating schedule, and their combination on body weight and abdominal fat area and cardiometabolic outcomes in people with metabolic syndrome.

Participants were allowed to choose between early TRE (eTRE; eating earlier in the day) and late TRE (lTRE; skipping breakfast) to keep their social eating pattern. The researchers hypothesized that TRE is effective in improving metabolic disease risk parameters without the restriction of carbohydrate consumption and that a combination of TRE with LCD leads to additional metabolic benefits.

The study demonstrated the following findings:

• Compared with baseline, all 3-month treatments significantly reduced body weight and subcutaneous fat area. Still, only TRE and combination treatment reduce visceral fat area (VFA), fasting blood glucose, uric acid (UA), and dyslipidemia.
• Compared with changes in LCD, TRE and combination treatment further decrease body weight and VFA, while only combination treatment yields more benefits on glycemic control, UA, and dyslipidemia.

"All three treatments after a 3-month intervention reduced subcutaneous fat area, as well as some cardiometabolic outcomes, including C-peptide, fasting insulin, and insulin sensitivity index," the researchers wrote in their conclusion. "Only TRE, with and without low carb diet, significantly reduced abdominal visceral fast, uric acid, fasting blood glucose, triglyceride, and TG/HDL-c ratio. TRE and combination treatment decreased VFA and body weight compared with LCD changes."

Time-restricted eating is superior to low-carbohydrate diet in reducing abdominal visceral obesity and body weight. Therefore, 8-h Time-restricted eating without and with low-carbohydrate diet can serve as an effective intervention for metabolic syndrome (MetS).