The Endocrine Society
The Endocrine Society
March 24, 2019
2 min read

Verified meal, sleep window research explores meal timing as weight-loss strategy

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NEW ORLEANS — Eating later into the evening was associated with going to bed later and with having a greater BMI and fat mass in a group of mostly women with overweight and obesity, according to data presented at the Endocrine Society Annual Meeting.

Adnin Zaman

“We are certainly not the first group to show an association between delayed eating, sleep timing and BMI,” Adnin Zaman, MD, a research fellow at the University of Colorado, Denver, told Endocrine Today. “However, it has been challenging to apply sleep and circadian science to medicine due to a lack of methods for measuring daily, free-living patterns of human behavior.”

Zaman and colleagues used three methods for determine eating and sleeping behaviors during a 7-day study of 32 adults (mean age, 36.4 years; 90% women) with overweight and obesity (mean BMI, 33.4 kg/m2). Researchers measured physical activity and sedentary time during the day with a thigh-mounted accelerometer. Sleep duration was assessed by an actigraph watch worn on the nondominant hand. Eating was recorded using a food diary app to photograph everything ingested and backed up with continuous glucose monitoring.

“This gave us information on food content, but also a time stamp of when they were eating,” Zaman said. “We were then able to compile this data to see the first and last eating event for each patient in order to calculate the duration of time in the day they ate food.”

Mean eating duration throughout the day among the participants was 11 hours, with the last food ingested at 7:54 p.m. on average.

“However, if you plot the points of all logged eating events of all patients on a clock, participants were eating food nearly 24 hours throughout the day,” Zaman said.

Mean sleep duration was 7.2 hours. The later the midpoint of a participant’s eating window during the day, the later the midpoint of sleep window tended to be (P < .0001). Sleep duration was not influenced by sleep timing. A later eating midpoint was also correlated with a higher BMI (P = .005) and fat mass (P = .001).

“[We] found that individuals with overweight/obesity may be eating later into the day,” Zaman said. “The participants from which these data were obtained are now going through a behavioral weight-loss trial where we are asking half of the cohort to restrict their eating to a 10-hour window, starting within 3 hours of their wake time, and the other half are given no instructions regarding timing of eating.” by Jill Rollet



Zaman A, et al. SAT-096. Later timing of energy intake associates with higher fat mass in adults with overweight and obesity. Presented at: The Endocrine Society Annual Meeting; March 23-26, 2019; New Orleans.

Disclosure: Zaman reports she received research funding from the NIH.