Research carried out at the Peninsula Medical School in the South West of England has discovered that obesity in later life does not make a substantial difference to risks of death among older people but that it is a major contributor to increased disability in later life - creating a ticking time bomb for health services in developed countries.

The research is published in the August 2008 edition of the Journal of the American Geriatrics Society.

The Peninsula Medical School research team worked with data on just under 4,000 participants in the English Longitudinal Study of Ageing (ELSA) aged 65 and older and living in the community. Each participant had their weight and height measured and their BMI (body mass index) calculated and they were followed up for five years. The researchers compared people with BMI of 20 to 24.9 (i.e. those of recommended weight), with those who had a BMI of 25 to 29.9 ("overweight"), 30 to 34.9 ("obese"), or 35 or over ("severely obese").

The results showed that the higher an older person's BMI, the more likely he or she was to develop mobility problems (measured using a standard performance test) or to develop difficulty carrying out everyday tasks. The results also showed that, in older people, the link between higher BMI and the risk of death is weak - only severely obese older men seemed to run this increased risk.

Dr Iain Lang, who led the research from the Peninsula Medical School, commented: "We have known for some time that young and middle-aged adults who are overweight run a higher risk of death and it was presumed that this held true for older people. In fact, our results show that the risk of dying is higher only for the most severely obese but that all older people who are overweight are at significantly increased risk of developing problems with mobility and carrying out everyday tasks."

He added: "This research is important because a growing proportion of the population is aged 65 or over, and more and more of these older people are overweight. In fact, in most developed countries middle-aged and elderly adults are more likely to be obese than people in any other age group. These findings have huge significance for the delivery of health care, both now and in the future. Increasing numbers of older people and higher levels of overweight and obesity will lead to a greater burden of disability and ill health and place an immense strain on health and social services. The issue is likely to get worse as time goes on and represents a ticking time bomb for health services around the world."

The research team recommends that older people should talk to their doctor or other health care professional about their weight, and take their advice regarding slimming down if they are overweight. The advice may include more exercise, a change in diet, or both.

Lindley Owen, Consultant in Public Health at Cornwall and Isles of Scilly Primary Care Trust, said: "Staying a healthy weight can be a fun and relatively easy thing to do, even as people get older. People don't have to join a gym or take on complicated new diets. There are many everyday opportunities to stay active through regular walking, gardening or social groups, while eating fresh, nutritious food is enjoyable at any age.

"Our experience of running supported walking and cycling groups has shown that older people benefit in many ways from regular physical activity. Not only do they get fitter and physically stronger but the enjoyment of spending time with friends in the open air can give new confidence and a real zest for life.

"People are living longer but this study shows that excess weight can have a real impact on the quality of people's lives which can reduce the benefit of those extra years. We must do all we can to encourage older friends or relatives to build enjoyable exercise into their daily routine and develop good habits ourselves to take into our retirement years. People can visit strollbacktheyears or healthpromcornwall (01209 313419) for more advice."

Dr Gill Lewendon, Consultant in Public Health Medicine, Plymouth Teaching PCT, added: "This report highlights the problem of obesity in an increasingly ageing population. The PCT and City Council work closely with a wide range of voluntary and statutory agencies to provide increased opportunities for everyone to eat more healthily and to move around a bit more. For those who are already very overweight or obese, the PCT provides a comprehensive weight management service for people of all ages. "

More information is available by logging on at pms.ac.

The Peninsula Medical School is a joint entity of the University of Exeter, the University of Plymouth and the NHS in the South West of England, and a partner of the Combined Universities in Cornwall. The Peninsula Medical School has created for itself an excellent national and international reputation for groundbreaking research in the areas of diabetes and obesity, neurological disease, child development and ageing, clinical education and health technology assessment.

Peninsula Medical School