"We found that eating four hours later makes a significant difference for our hunger levels, the way we burn calories after we eat, and the way we store fat," Vujović said.

"Together, these changes may explain why late eating is associated with increased obesity risk reported by other studies and provide new biological insight into the underlying mechanisms.".

The study does show eating later results in "an increase in hunger, impacts hormones and also changes gene expression, especially in terms of fat metabolism with a tendency towards less fat breakdown and more fat deposition," said Dr.

While prior studies have linked later eating to weight gain, this study did not measure weight loss and cannot show a causal link, said Kolla, who was not involved in the study?

"While there have been other studies investigating why late eating associates with an increased risk for obesity, this may be the most well controlled, including strictly controlling the amount, composition and timing of meals, physical activity, sleep, room temperature and light exposure," said senior author Frank Scheer, director of the Medical Chronobiology Program in the Brigham's Division of Sleep and Circadian Disorders.

"What is new is that our results show that late eating causes an increase in the ratio of ghrelin and leptin averaged across the full 24-hour sleep/wake cycle," Scheer said.

"These changes in appetite-regulating hormones fits well with the increase in hunger and appetite with late eating," Scheer said.