Taking a late lunch makes it much harder for people to lose weight, according to researchers.

Researchers from Brigham and Women's Hospital in Boston and the University of Murcia studied overweight people who followed a 20-week weight-loss treatment programme in Spain.

In a 420-strong group of people taking part in a 20-week diet, half of the group ate lunch - their biggest meal of the day - before 3pm, while half ate later.

Those who ate before 3pm lost 30 per cent more weight than those who dined later, the 'Daily Mail' reported.

Late lunchers lost an average of 7.7kg, compared with 9.9kgs for early lunchers.

"This is the first large-scale prospective study to demonstrate that the timing of meals predicts weight-loss effectiveness," senior author Dr Frank Scheer, from BWH said.

"Our results indicate that late eaters displayed a slower weight-loss rate and lost significantly less weight than early eaters, suggesting that the timing of large meals could be an important factor in a weight loss programme," Scheer added.

The team divided the participants into two groups: early eaters and late eaters. During this meal, 40 per cent of the total daily calories were consumed.

Early eaters ate lunch any time before 3pm and late eaters, after 3pm. They found that late eaters lost significantly less weight than early eaters, and displayed a much slower rate of weight loss.

The researchers found that timing of other, smaller, meals did not play a role in the success of weight loss.

However, the late eaters - who lost less weight - also ate fewer calories during breakfast and were more likely to skip breakfast altogether. Late-eaters also had a lower estimated insulin sensitivity, a risk factor for diabetes.

The researchers also examined other traditional factors that play a role in weight loss such as total calorie intake and expenditure, appetite hormones leptin and ghrelin, and sleep duration.

Among these factors, researchers found no differences between both groups, suggesting that the timing of the meal was an important and independent factor in weight loss success.

"This study emphasises that the timing of food intake itself may play a significant role in weight regulation," study co-author Doctor Marta Garaulet, from the University of Murcia, said.