In a recent article published in Jama Network Open, researchers discuss the findings of a six-month-long randomized clinical trial (RCT) evaluating time-restricted eating (TRE) without calorie counting instead technique to day by day calorie restriction (CR) for reducing body weight and regulating glucose levels in patients with type 2 diabetes (T2D).
Study: Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial. Image Credit: Serenko Natalia / Shutterstock.com
Current estimates indicate that T2D affects about 10 million people in the US alone. Globally, T2D cases are increasing, with some researchers projecting that up to 1 in three U.S. adults will probably be affected by this condition by 2050.
Although CR is essentially the most commonly prescribed intervention in T2D, it is usually tedious to follow and difficult to stick to, thereby limiting patient compliance. Thus, there stays an urgent need for alternative intervention strategies for T2D, corresponding to TRE.
Up to now, studies investigating the results of TRE in patients with T2D are limited. In a single study investigating a 10-hour TRE intervention for 12 weeks in 120 obese adults with T2D, researchers observed that the study participants lost about 3.5% body weight as in comparison with controls. Similarly, a nine-hour TRE intervention reduced body weight by 1.1% in only three weeks in a small cohort of 14 obese men and girls with T2D.
In regards to the study
In the current study, researchers recruited 75 adults between 18 and 80 years of age with a previous diagnosis of T2D. Each study participant was randomly placed into the CR, TRE, or control group. All included participants had hemoglobin A1c (HbA1c) levels between 6.5-11% g/dl and body mass index (BMI) values between 30-50 kg/m2.
The TRE group participants ate with no restrictions on the kind or quantity of food through the eight-hour eating window between 12:00 and eight:00 p.m. day by day. Nonetheless, this group fasted for 16 hours from 8:00 p.m. to 12:00 p.m. the next day, during which they only consumed water and energy-free drinks. CR group participants reduced their calorie intake by 25% of their baseline energy requirements throughout the trial.
All participants met with the study dietitian from baseline to the third month, who maintained a record of their body weight, food plan adherence, medication changes, and antagonistic events. TRE and CR group participants also adhered to their physical activity routines and healthy food selections, thus conforming to American Diabetes Association (ADA) guidelines.
TRE and CR group participants also followed a medicine management protocol, which mandated that they reduce their dose of short-acting insulin by 50% while not changing the dose of long-acting insulin and discontinuing sulfonylureas when baseline HbA1c levels were below 7%.
Nonetheless, if HbA1c levels exceeded 7% as much as 8.5%, the dose of sulfonylureas was reduced by 50% while not changing the long-acting insulin dose and reducing the short-acting insulin dose by 10%. When baseline HbA1c levels exceeded 8.5%, all medication doses remained the identical.
As the first final result, the researchers measured the proportion change in body weight among the many TRE, CR, and control groups by six months. Other outcomes included time within the glycemic range, average glucose level, HbA1c levels, body composition, medication effect, blood pressure (BP), heart rate, plasma lipid profile, dietary intake and adherence, physical activity (PA), and antagonistic events.
Dual-energy x-ray absorptiometry was used to measure body composition, whereas the automated self-administered 24-hour (ASA-24) dietary assessment was used to measure dietary intake. Every day footsteps were quantified by PA levels.
All participants wore a continuous glucose monitor (CGM) or tested their blood glucose levels using a glucose monitor for no less than 10 days at baseline, in addition to three and 6 months. This allowed the researchers to detect hypoglycemia or hyperglycemia, reflected by glucose levels lower than 70 mg/dL or over 180 mg/dL, respectively.
The present RCT analyzed data from 75 participants, with 25 participants in each group, TRE, CR, and control. Women comprised 71% of the study cohort, whereas 53% of the study cohort were non-Hispanic Black. The common age, BMI, and HbA1c levels of those participants were 55 years, 39 kg/m2, and eight.1% g/dl.
The eight-hour TRE intervention was simpler for weight reduction than CR at -3.6% and -1.8%, respectively. BMI also decreased within the TRE group by month six but not within the CR group. HbA1c level reductions were similar within the TRE and CR groups relative to controls at -0.90% and -0.94%, respectively.
Each TRE and CR groups were related to comparable reductions in waist circumference but not visceral fat mass relative to controls. Notably, visceral fat mass is a sturdy factor related to changes in glycemic control.
CR typically reduces body weight by 4-7% after six months. Nonetheless, participants within the CR group on this trial reported greater difficulty with adhering to their intervention relative to TRE group participants, who easily adhered to their intervention and achieved higher overall energy restriction. It is probably going that the study participants previously tried calorie counting but found TRE easier, which may need increased overall adherence within the TRE group.
There have been no reports of any serious antagonistic events or influence of medication in any group.
Despite its relatively short duration, the present RCT addressed some critical knowledge gaps about intervention strategies which may improve the health of individuals with T2D. Importantly, the study population was representative of Hispanic and non-Hispanic Black adults for whom TRE could possibly be a highly appealing weight reduction approach while continuing to devour familiar foods.
TRE was protected in patients who rely on food plan or medications to regulate their T2D. Nonetheless, for people using sulfonylureas or insulin, its adoption would require medication changes and continuous monitoring, particularly through the initiation of the intervention.
Overall, this trial demonstrated that eight-hour TRE without calorie counting was an efficient alternative food plan strategy for weight reduction and reducing HbA1c levels for adults with T2D. Larger RCTs with longer follow-up durations are needed to substantiate these findings.
- Pavlou, V., Cienfuegos, S., Lin, S., et al. (2023). Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial. JAMA Network Open 6(10). doi:10.1001/jamanetworkopen.2023.39337