DIETERS who eat early lunches tend to lose more weight than those who have their midday meal on the later side, a new Spanish study suggests.
The finding does not prove bumping up your lunch hour will help you shed those extra kilos. But it is possible that eating times play a role in how the body regulates its weight, researchers say.
"We should now seriously start to consider the timing of food — not just what we eat, but also when we eat," says study co-author Dr Frank Scheer, from Brigham and Women’s Hospital and Harvard Medical School in Boston.
His team’s research included 420 people attending nutrition clinics in southeast Spain. Along with going to regular group therapy sessions with nutrition and exercise counselling, dieters measured, weighed and recorded their food, and reported on their daily physical activity.
Study participants were on a Mediterranean diet, in which about 40% of each day’s calories are consumed at lunch. About half of people says they ate lunch before 3pm and half after.
Over 20 weeks of counselling, early and late lunchers ate a similar amount of food, based on their food journals, and burned a similar amount of calories through daily activities.
However, early eaters lost an average of 10kg — just over 11% of their starting weight — and late eaters dropped 8kg, or 9% of their initial weight.
What time dieters ate breakfast or dinner was not linked to their ultimate weight loss, according to findings published in the International Journal of Obesity.
One limitation of the study is that the researchers did not assign people randomly to eat early or late — so it’s possible there were other underlying differences between dieters with different mealtimes. Certain gene variants that have been linked to obesity were more common in late lunchers, for example.
Overdoing it at dinner?
Dr Yunsheng Ma, a nutrition researcher from the University of Massachusetts Medical School in Worcester, says people who eat later may have extra food in their stomach when they go to sleep — which could mean more of it isn’t burned and ends up being stored as fat.
Dr Sheer says one other aspect to consider, for example, is glucose tolerance — how well you can deal with sugar in your food.
"Your body is better able to cope with that in the morning than in the evening," he says.
How often people eat during the day and whether they bring food from home or eat out may also contribute to weight loss, says Dr Ma, who was not involved in the new research.
He says any implications of late eating could be made worse among people in other countries, including South Africa, where "the pattern of consumption of meals is very different and problematic".
In South Africa, as in the US, many people skip breakfast or lunch — then end up overdoing it at dinner.
Dr Sheer says that in the US — where, as in South Africa, dinner is typically the biggest meal — researchers say they would expect people who eat later dinners to have more trouble losing weight, based on his team’s findings.
Regardless of exact meal times, Dr Ma says it’s important for people to spread their calories out throughout the day.
"Have a good breakfast and a good lunch, and at dinner, people should eat lightly," he advises — much like the old nutrition mantra about the healthiest eating pattern being to have "breakfast like a king, lunch like a prince and dinner like a pauper".
Reuters, with Marika Sboros