People should concentrate on exercise and staying fit – rather than dieting and weight loss – when it comes to cutting the risks of living with obesity.

A study, published in the journal Science, looked at existing research and data and compared the mortality risk-reduction associated with weight loss with that associated with an increase in physical activity and cardiorespiratory fitness.

The researchers found that the risk-reduction associated with increased fitness and physical activity was consistently greater than that achieved through intentional weight loss.

"Multiple surveys demonstrate a high prevalence of weight loss attempts over the past 40 years, during which, obesity prevalence has increased approximately three-fold," the report states.

"Thus, the intense focus on weight loss has not prevented excessive weight gain in recent decades.

"Moreover, repeated weight loss efforts may contribute to weight gain and is undoubtedly associated with the high prevalence of weight cycling, which is associated with significant health risks.

"In contrast to the inconsistent and inconclusive results of intentional weight loss, increasing either physical activity or cardiorespiratory fitness is associated with significant reductions in all-cause and cardiovascular disease mortality risk."

Called Obesity treatment: Weight loss versus increasing fitness and physical activity for reducing health risks, the study was authored by Professor Glenn Gaesser from Arizona State University and associate professor, Siddhartha Angadi, from the University of Virginia.

Gaesser said: "We realise that in a weight-obsessed culture, it may be challenging for programmes that are not focused on weight loss to gain traction.

"We're not necessarily against weight loss; we just think that it shouldn't be the primary criterion for judging the success of a lifestyle intervention programme."

To read the full report, click here.