(USA TODAY) -- Dieters have long been told not to eat too many calories late in the day.
Now, a new study suggests that dieters who eat lunch early lose more weight than those who eat a late lunch.
should start to consider meal timing in addition to calories and meal
composition when thinking about weight loss," says the study's senior
author Frank Scheer, an associate neuroscientist at Brigham and Women's
Hospital and an assistant professor of medicine at Harvard Medical
To come to this conclusion, Scheer and researchers at the
University of Murcia in Spain and Tufts University in Boston, studied
420 overweight and obese people who participated in a 20-week
weight-loss program in Spain.
The mid-day meal is often the
biggest one of the day in this Mediterranean culture. Participants
consumed about 40% of their daily calories (roughly 550 to 570) at
Half of the participants were considered early eaters
because they had lunch before 3 p.m. Half were classified as late eaters
because they had their mid-day meal after 3 p.m.
participants consumed an average of about 1,400 calories a day during
the weight-loss program. There was no significant difference in caloric
intake or energy expenditure between late lunch and early lunch eaters.
Among the findings reported Tuesday in the International Journal of Obesity:
Those who ate lunch earlier in the day lost an average of 22 pounds in
20 weeks; those who ate lunch later lost about 17 pounds.
late eaters consumed fewer calories during breakfast and were more
likely to skip breakfast than early eaters. (Dieters are often advised
to eat breakfast.)
-- The late lunch eaters had lower insulin sensitivity, which is a risk factor for diabetes.
cannot directly translate these findings to Americans, but we would
expect that a later dinner -- the main meal for most Americans -- might
similarly impair weight loss, " Scheer says. "But research is required
to test that."
He says researchers don't know why weight loss was
greater in the early eaters, but one hypothesis is that glucose (sugar)
is processed differently depending on the time of day. Another theory is
that the timing of meals can impact the circadian system (the body's
clock) which may disrupt the proper function of the liver and fat cells,
Elizabeth Ward, a registered dietitian in Boston and author of MyPlate for Moms: How to Feed Yourself and Your Family Better,
says this "an interesting study, but it's an observational study, so it
doesn't prove cause and effect. If you cut back of your calories at any
time of the day, you will lose weight."
Still, the research
indicates that if you eat your calories earlier in the day, it may give
you an edge with weight loss, Ward says.
She says there may be some truth to the old adage: "Eat breakfast like king, lunch like a prince and dinner like a pauper."