Dieting may help reduce early deaths among obese patients, a new study has found.
With or without exercise, weight-reducing diets - usually ones that are low in fat and saturated fat - can reduce the risk of premature death for obese people, the authors said.
Being obese - or having a body mass index score of 30 or over - is associated with premature death.
It can lead to a number of life-threatening complications including some cancers, coronary heart disease and type 2 diabetes.
A team of researchers based at the University of Aberdeen and the University of Auckland in New Zealand set out to assess the effects of weight loss programmes on deaths from all causes as well as from heart disease and cancer.
Their study, published in the British Medical Journal (BMJ), examined 54 studies with data on 30,000 adults dating from 1966 to 2016 with a minimum follow-up time of one year.
They found that during the average follow-up period of two years, weight-loss diets were associated with an 18% relative reduction in premature death among obese people.
They said that this corresponds to six fewer deaths per every 1,000 participants in the studies.
But they were unable to show if there was any effect of weight-reducing diets on deaths from heart disease and cancer, or whether the participants saw any protective effect from developing these conditions.
"Our data support public health measures to prevent weight gain and facilitate weight loss using these types of diet," they concluded.
The study comes as a group of nutrition scientists released a "consensus statement" on whole grain foods.
The International Carbohydrate Quality Consortium said that the consumption of quality whole grains, particularly those with a low glycaemic index, is associated with lower mortality rates and lower risk of type 2 diabetes, cardiovascular disease, obesity and possibly bowel cancer.
The committee, including UK academic Dr Marie-Ann Ha of Anglia Ruskin University, said that people should consume about two servings of whole grains a day.
They said that whole grains, such as those found in wholemeal bread, pasta and brown rice, are important sources of dietary fibre, nutrients and phytochemicals in the diet.