Parental link to obesity

April 24, 2007

Women who begin their menstrual periods before they are 11 years old are more likely to have children who also start puberty early and are more overweight than the children of mums who mature later. The finding is from a study of more than 6,000 children who participated in Bristol University’s ALSPAC study.

The research, led by Dr Ken Ong, a paediatric endocrinologist at the Medical Research Council Epidemiology Unit and University of Cambridge, is published in Public Library of Science Medicine.

Along with colleagues in Bristol, the research team looked for links between a mother’s age at puberty, adult body size and obesity risk and her children’s growth and obesity risk. In the study, 6,009 children had growth and fat mass measurements taken at 9 years old. Detailed infancy and childhood growth data were also examined for a smaller group of 914 children.

Dr Ong’s team found that mothers who go through puberty early tend to be shorter and fatter than other mums and, on average, they give birth to children who grow rapidly during infancy but become overweight as children and start puberty earlier.

This growth pattern appears to be passed on from mother to child making it likely that it is due to genetic factors. Other possible causes are feeding patterns or behaviours that run in families. Identifying what these inter-generational factors actually are could help develop new ways of preventing and tackling obesity.

Dr Ken Ong explains: “Some children have a rapid ‘tempo of growth’, in that they may not be particularly tall as adults, but they reach their adult height sooner than other kids - they grow rapidly during childhood, mature faster and stop growing sooner. Paediatricians have long been aware that some children show this pattern of development around the time of adolescence. Now we know that this rapid growth pattern starts as soon as you’re born. In fact, most of the speedy growth takes place during infancy. Beyond links to early puberty, most importantly this growth pattern appears to lead to an increased risk of obesity that lasts from childhood through to adult life.”

He concludes: “Obesity is a major health problem, even in young children, and general public health strategies seem to be making little impact on the growing numbers of obese children. The current Department of Health and WHO recommendations for infant nutrition promote exclusive breast feeding and introduction of weaning foods at around 6 months old. Knowing that rapid infancy weight gain, early puberty and obesity run together in families may help us identify which children to best target our efforts at right from birth.”

Dr Ong’s ongoing research will follow-up the findings of this study by looking for specific genetic links to rapid early growth and development. The team will also assess the effect of different diets in preventing infants from becoming unhealthily overweight.

Source: University of Bristol