Obese young children are vulnerable to bone fractures and more likely to develop osteoporosis in old age, according to new research seen exclusively by The Independent on Sunday.
Overweight children develop bigger skeletons in order to carry their extra weight. A study of 499 healthy six-year-old children - to be presented at the British Society for Rheumatology conference this week - found their bigger bones have 5 to 6 per cent lower bone density, because they lack enough minerals to make them strong. Higher rates of fractures in fat children had previously been linked to clumsiness and poor co-ordination.
The Medical Research Council (MRC) study suggests childhood obesity will increase the risk of osteoporosis, and debilitating hip and back fractures in old age, as 90 per cent of bone mass is acquired in childhood, directly affecting how strong bones are in later life.
The children are part of a much larger cohort being studied by MRC scientists at the Lifecourse Epidemiology Unit in Southampton, in an attempt to understand how lifestyle, diet and other environmental factors in pregnancy and childhood influence diseases of ageing, such as type 2 diabetes and heart disease. Studies have already identified links between childhood obesity and asthma, and fractures and fizzy drinks.
Dr Zoe Cole, rheumatologist and researcher, said the findings made tackling childhood obesity even more urgent as the costs of osteoporosis are unaffordable. One in three British children are either overweight or obese.
Dr David Haslam, chairman of the National Obesity Forum, said: "We need the Government to stop their wishy-washy initiatives and to show some political will to prevent obesity in children and to improve management for those already overweight. Being overweight in childhood isn't a death sentence, but children need help to lead healthier lives."
Bone is living tissue that changes constantly, with bits of old bone being replaced by new. During childhood and adolescence, much more bone is deposited than withdrawn, so the skeleton grows in size, strength and density, a process that reaches its peak at the age of 30-35.
Fractures are most common in children and the elderly. Breaking a bone ultimately depends upon two factors: the strength of the bone and the forces applied to it.
Losing a lot of bone mass in later life can lead to osteoporosis which causes fractures in half of all women and one in five men over 50 in Britain.
Fractures in old age cost the UK £5.1bn (NZ$10.7bn) every year, according to the International Osteoporosis Foundation - a figure expected to rise as people live longer.
Hip fractures among the elderly are strongly associated with admissions to hospital and care homes, and even with early death.
Obesity costs the UK's National Health Service and economy £20bn, according to the government research body Foresight.
Last week the national eating disorders charity Beat took the unexpected step of extending its services to people with obesity, reflecting a growing demand for psychological support from Britain's increasingly obese population.
Dr Cole said: "Obesity in young children has major implications for many aspects of adult health. People are living longer, so if overweight children are starting off with poor bones, osteoporosis rates will rise regardless of current prevention strategies.
"If some children could revert to normal weight and near-normal bone density, then it would make an enormous difference to the bone health of the population as a whole."