Eating later in the day may contribute to weight gain, according to a new study to be presented Saturday at ENDO 2019, the Endocrine Society's annual meeting in New Orleans, La.

The study used three types of technology to record participants' sleep, physical activity and eating patterns. It has been challenging to apply sleep and circadian science to medicine due to a lack of methods for measuring daily patterns of human behavior.

The week-long study included 31 overweight and obese adults, average age 36. Ninety percent were women. They were enrolled in an ongoing weight-loss trial comparing daily caloric restrictions to time-restricted feeding, meaning they could only eat during certain hours of the day.

Participants wore an active PAL electronic device on their thigh. This device measured how much time they spent in physical and sedentary activities. They also wore an Actiwatch, which assesses sleep/wake patterns. Participants were asked to use a phone app called Meal Logger to photograph and time stamp all meals and snacks throughout the day.

The researchers found that on average, participants consumed food throughout an 11-hour timeframe during the day and slept for about 7 hours a night. People who ate later in the day slept at a later time, but they slept for about the same amount of time as those who finished eating earlier. Later meal timing was associated with a higher body mass index as well as greater body fat.