Time-restricted eating, compared to calorie restriction, fails to provide significant benefits in NAFLD: TREATY-FLD trial

The study found that TRE did not produce additional benefits for reducing body fat, metabolic risk factors, and intrahepatic triglyceride (IHTG) content in adults with obesity NAFLD. The findings from the 12-month randomized clinical trial, published in JAMA Network Open, support the importance of caloric restriction with the use of TRE for obese adults with nonalcoholic fatty liver disease.

NAFLD is a significant public health challenge globally, affecting about 20% to 30% of adults in the general population, and more than 70% of patients with diabetes and obesity have NAFLD. NAFLD is closely related to hypertension, hyperlipidemia, type 2 diabetes, and obesity and has been linked with an increased risk of CVDs (cardiovascular diseases). Weight loss through lifestyle modifications has been shown to improve metabolic disorders and liver fat.

Dietary calorie restriction has been reported to reduce intrahepatic lipid levels and weight among NAFLD patients effectively but adhering to lifestyle modification for the long term is challenging. The TRE regimen has gained popularity because it enhances adherence and reduces weight. However, there was no clarity on the safety and efficacy of time-restricted eating on nonalcoholic fatty liver disease.

Against the above background, Xueyun Wei, Nanfang Hospital, Southern Medical University, Guangzhou, China, and colleagues conducted the TREATY-FLD randomized controlled trial comparing the effects of TRE versus daily calorie restriction (DCR) on IHTG content and metabolic risk factors in patients with NAFLD and obesity. They hypothesized that 8-hour TRE would be more effective than DCR in improving metabolic risk factors and NALFD.

The 12-month randomized clinical trial included adults with NAFLD and obesity. They were randomly assigned to TRE (consuming food only between 8:00 am and 4:00 pm) or DCR (habitual meal timing). All participants were instructed to diet maintenance of 1200 to 1500 kcal/d for women and 1500 to 1800 kcal/d for men for 12 months.

A change in IHTG content was measured by MRI (primary outcome), and secondary outcomes included changes in body weight, body fat, waist circumference, metabolic risk factors, and body fat. Intention-to-treat analysis was used.

The authors reported the following findings:

• A total of 88 eligible patients with obesity and NAFLD (mean age, 32.0 years; 56% were men; and mean body mass index, 32.2) were randomly assigned to the TRE (n = 45) or DCR (n = 43) group.
• The IHTG content was reduced by 8.3% in the TRE group and 8.1% in the DCR group at the 6-month assessment.
• The IHTG content was reduced by 6.9% in the TRE group and 7.9% in the DCR group at the 12-month assessment.
• IHTG content changes were comparable between the two groups at six months (percentage point difference: −0.2) and 12 months (percentage point difference: 1.0).
• Body weight, liver stiffness, and metabolic risk factors were significantly and comparably reduced in both groups.

"Our results showed that a TRE regimen did not achieve additional benefits for reducing body fat, weight, IHTG content, and metabolic risk factors compared with DCR. TRE might be more effective in improving insulin sensitivity than DCR in obese adults with NAFLD," the researchers showed.

The researchers also showed that both diets produced a comparable effect on the resolution of NAFLD and liver stiffness. "These data support the importance of calorie restriction while adhering to TRE regimen for NAFLD management," they concluded.

Reference:

Wei X, Lin B, Huang Y, et al. Effects of Time-Restricted Eating on Nonalcoholic Fatty Liver Disease: The TREATY-FLD Randomized Clinical Trial. JAMA Netw Open. 2023;6(3):e233513. doi:10.1001/jamanetworkopen.2023.3513