Scientists from Glasgow and Bristol universities conducted a study to identify the triggers of childhood obesity, based on the theory that a child's early environment can influence their weight in later life.
The study, published last week by the British Medical Journal, involved 9,143 seven-year-olds in the Avon longitudinal birth cohort study of parents and children. Researchers examined 25 potential obesity risk factors, of which eight were found to be significantly associated with childhood obesity. These are:
* Parental obesity (one or both parents)
* More than eight hours spent watching television per week at the age of three
* Sleeping less than 10.5 hours a night at the age of three
* Heavy birthweight
* Size in early life, measured at eight and 18 months
* Rapid weight gain in first year
* Rapid catch-up growth between birth and two years
* Early development of body fatness at pre-school age
The researchers said the precise mechanisms by which the eight risk factors increase the risk of obesity are complex. For example, parental obesity could increase the risk of childhood obesity through genetics, or by shared family characteristics such as food preferences.
Similarly, the duration of night sleep may affect the risk of obesity by altering growth hormone secretion, or because more sleep reduces the amount children eat in the evenings. Alternatively, children who are more physically active may sleep longer at night.
The authors said that interventions must now target children from a much younger age. They said, 'Most interventions to prevent obesity have tried to change the lifestyles of children and adolescents and have been unsuccessful. Future interventions might focus on environmental changes targeted at relatively short periods in early life.'
Dr David Haslam, chair of the National Obesity Forum, agreed. He said, 'This paper identifies fundamental, deep-rooted causes of obesity, presenting us with a course of action for prevention that must start on day one. As part of the action, educating new mothers at antenatal and pre-conception stage is vital.'
The report is available at http://bmj.bmjjournals.com/onlinefirst_date.shtml.