Weight loss in Type 2 Diabetes - Time-restricted eating or caloric restriction

1 in 10 US resident has type 2 diabetes. It is estimated that that this will increase to 1 in 3 by 2050, if the current trend continues. The traditional method of caloric restriction (CR) has become increasingly difficult due to several reasons. Time-restricted eating (TRE) is a popular alternative which involves confining daily food intake to limited hours and fasting for the remaining hours. 

METHODOLOGY 

The study was a 6-month duration randomized control trial from University of Illinois, Chicago. The study included a total of 75 participants 

• diagnosed with type 2 diabetes having their HbA1c levels between 6.5% to 11.0%
• aged 18 to 80 years
• body mass index between 30 to 50.

Participants were randomly divided into 3 groups:

• TRE group – 25 participants ate ad libitum between 12 and 8 pm during the day and were limited to calorie-free liquids between 8 pm to next day 12 pm without calorie monitoring. 
• CR group – 25 participants reduced their calorie intake by 25% of their baseline energy needs daily. 
• Control group – were instructed to maintain their weight and usual eating and exercise habits. 

All participants met with the dietician dedicated to this study every week for initial 3 months and then biweekly thereafter. TRE and CR groups were taught how to make healthy food choices as per the American Dietary Association`s nutrition guidelines. All participants were instructed not to change their physical activity habits throughout the trial. 

RESULTS

At the end of 6 months of intervention the authors recorded the following changes: 

PRACTICAL IMPLICATIONS

The authors have found time restricted eating to be effective for weight loss and HbA1c reduction for Hispanic and non-Hispanic Black Americans adults as the sample representation was from these groups. 

To help the Type 2 diabetes population, they suggest that TRE is safe for patients who are on diet alone or medication alone for glycemic control. However, for those on sulfonylureas and/or insulin, TRE will require regular monitoring with medication changes, particularly in initial stages of the diet. 

LIMITATION

The authors suggest research limitations included

• Relatively short duration of the trial
• Lack of participants blinding
• Majority of the participants were using sodium-glucose transport protein 2 inhibitors and glucagon like peptide-1 receptor agonist which may have influenced body weight findings. 
• Reliance on participants` self-report of energy consumption may have led to inaccuracies. 

SOURCE

This research paper was published on JAMA Network Open on October 27, 2023. The lead author of this paper is Krista A. Varady, PhD, Department of Kinesiology and Nutrition, University of Illinois Chicago.