Obesity can cause an excessive burden on the spines of children and adolescents, according to researchers at the University of Otago Medical School, Dunedin, New Zealand.

Heavy children require stronger bones than leaner children. Researchers conducted a study to examine the compensatory increases in the spinal bone mineral content and area shown by overweight and obese children and adolescents.

Researchers measured the vertebral area and bone mineral content of lumbar vertebrae L2-L4 in 202 boys and 160 girls, ages 3 to 19 years. The children were categorized as being normal weight, overweight or obese using standard body mass index calculations.

Compared with children of healthy weight, the overweight and obese children had lower vertebral bone mineral content for their bone area, body height, body weight and puberty development, according to the study published in Osteoporosis International. Spinal area was low in overweight and obese girls compared with girls of healthy weight but overweight and obese boys had enlarged their vertebral area appropriately for their increased body size.

"We conclude that during growth, overweight and obese children do not increase their spinal bone mineral content to fully compensate for their excessive weight," wrote the authors. "Limiting excessive adiposity [obesity] in childhood and adolescence should help to avoid excessive loading and stresses on the lumbar spine."

Other sources: Osteoporosis International