Theories abound about the best way for people to lose weight. Now, recent findings from the Perelman School of Medicine at the University of Pennsylvania suggest that eating late at night may not only derail individuals’ efforts to lose weight but also raise their insulin and cholesterol levels as well as their risk of heart disease, diabetes and other health problems.

For the study, researchers asked nine healthy-weight participants to eat three meals and two snacks between 8 a.m. and 7 p.m. for eight weeks and then consume the same number of meals and snacks between noon and 11 p.m. for another eight weeks. (In between, folks adhered to a two-week washout period to ensure that there’d be no carryover effects.)

During this 18-week stretch, individuals slept between 11 p.m. and 9 a.m., and scientists measured changes in their weight, metabolism and calories burned.

Results showed that folks who ate later in the day gained weight. In addition, those participants experienced a rise in levels of insulin, glucose, cholesterol and triglycerides. Researchers noted that certain hormones in the early eaters peaked at the right time, which may have kept them from overeating.

Now that’s some news weight watchers can use!