Q&A: Time-restricted eating may be effective strategy for weight loss

A recent pilot study showed that time-restricted eating, a weight management strategy in which food is consumed in a set time period, was as good as more complex weight loss interventions.

The results of the study, published in PLoS One, suggest that further study on this strategy is merited, according to researchers.

In their pilot study, researchers recruited adults seeking to lose weight from February 2018 through June 2018 at community weight clinics and through advertisements, university staff bulletins and on social media.

Adults were eligible if they had a BMI over 30 kg/m2, or had a BMI over 28kg/m2 in addition to comorbidities. Individuals with conditions precluding fasting, including those who had experienced eating disorders, were pregnant or breastfeeding, or who were already using the diet or another fasting weight management strategy, were excluded from the study.

After completing initial telephone calls or emails to screen for eligibility, participants were weighed and had their BP and blood samples for lipid profiles taken at baseline visits. At this visit, researchers explained the intervention to participants.

For the intervention, participants were asked to limit eating to an 8-hour time period each day for 12 weeks. Outside these 8 hours, participants could drink water, diet drinks and coffee or tea without milk and sugar.

Participants received follow-up phone calls at 2, 3, 4 and 5 weeks, and had follow-up visits at 6 and 12 weeks.

The mean age of participants was 50 years, and they had a mean weight of 97 kg and mean BMI of 35.

During the study, 64% of participants practiced time-restricted eating (TRE) at least 5 days per week, and 58% continued to do so at week 12.

Researchers determined that, in those with follow-up data available, participants who adhered to TRE for at least 5 days each week experienced greater weight loss than those who did not at week 6 (-2.5 kg vs. -1 kg, P = 0.003) and week 12 (-3.5 kg vs -1.3 kg; P = 0.001).

According to the researchers, 26% of participants lost at least 5% of their body weight at baseline at 12 weeks. They did not identify effects on BP or lipid profile.

Healio Primary Care spoke with Dunja Przulj, PhD, lead author of the study and a research health psychologist in the Health and Lifestyle Research Unit at Queen Mary University of London, United Kingdom, to learn more about the findings and TRE.

Q: What is TRE?

A: TRE is a form of intermittent fasting where people only eat within a specific window (eg from 12 p.m.-8 p.m.) every day. The rest of the time they fast. No calorie restriction or special diet is required.

Q: Is TRE a feasible method of weight loss?

A: The results from our pilot study suggest it is feasible to do. At 12 weeks, around 60% of participants were still doing TRE at least 5 days per week, and they lost on average around 3.5 kg.

Q: What additional research is needed to assess the effectiveness of TRE?

A: The approach needs to be tested in a randomized controlled trial, and with a long-term follow-up, such as 1 year. More research is also needed to examine what period of fasting is optimal, and whether the timing of the eating period matters (eg early vs. late).

Q: Which patients would benefit most from TRE?

A: If TRE is an effective approach to weight loss, it should benefit anyone trying to lose weight. It may be particularly good for those people who struggle to stick to conventional weight loss approaches, which require calorie counting and restriction.

References:

Eurekalert. Successful pilot study of time restricted eating weight loss plan. https://www.eurekalert.org/pub_releases/2021-01/qmuo-sps012621.php. Accessed February 9, 2021.

Przulj D, et al. PLoS ONE. 2021;doi : 10.1371/journal.pone.0246186.