Abstract

This study assessed the impact of early childhood weight gain at birth, 0-5 years of age, and 5-9 years of age and its effects on metabolic health at nine years of age. The findings indicate that most excess weight is gained by 5 years of age and this weight gain is a predictor of metabolic health at 9 years of age. This finding is useful for public health interventions (which currently target school aged children) to tailor their programs to target preschool aged children where factors that contribute to weight gain are likely to be found in the family and the home as opposed to the school setting. Background: In recent years, there has been a rise in the incidence of childhood obesity globally, and as a result there has also been an associated rise in the incidence of illnesses such as, type II diabetes and hypertension. Based on an article previously published within this digest, it was found that boys aged 7-13 and girls aged 10-13 with higher than average Body Mass Index face a greater risk of developing coronary heart disease in adulthood*. It is important to know at what stage (birth, preschool, or primary school) in a child's development excess weight is gained so that preventative strategies may be tailored to that specific stage in development. Thus, this study assessed the impact of early childhood weight gain at birth, 0-5 years of age, and 5-9 years of age and its effects on metabolic health at nine years of age. This study differs from others as it is one of the first contemporary longitudinal cohort studies to measure the impact of early weight gain on metabolic health.

Methods: 261 healthy children with a mean age of 4.9 years were recruited between 2000 and 2001 from randomly selected schools in Plymouth, United Kingdom. The children were reviewed annually and fasting blood samples, body composition, physical activity, resting energy expenditure, heart rate variability, and anthropometry (height, weight, Body Mass Index, and waist circumference) were measured. Weight was measured to the nearest 200g as expressed as a SDS score, which is a standardized score that measures weight against height. A child with any gain in weight SDS would reflect excess weight gain. Height was measured to the nearest 1mm. Fasting blood samples were taken for insulin, glucose, total cholesterol, triglyceride and high-density lipoprotein cholesterol. Gestational age and birth weight for all children were available through a child health registry. The association between height, weight, Body Mass Index, waist circumference and metabolic health were assessed. An analysis was conducted to test whether weight gain can predict composite metabolic score. A composite metabolic score, which was based on the metabolic syndrome, was used to express metabolic status. These assessments took place at two time points in which the mean ages were 5 and 9 years.

Findings: The findings suggest that most excess weigh is gained by 5 years of age. Excess weight gain was substantial from 0 to 5 years of age but minimal from 5 to 9 years. More specifically, of the excess weight gained by 9 years of age, 91% was gained by the age of 5 years in girls and 70% was gained by the age of 5 years in boys. The composite metabolic score at 9 years of age was substantially higher among those who were overweight or obese compared with those of normal weight. Birth weight was a poor predictor of later weight gain. Birth weight did not have an impact on metabolic health; however, both early (0-5 years) and later (5-9 years) weight gain contributed significantly to predicting metabolic score at 9 years of age.

Conclusions: The study suggests that if children are targeted for weight control strategies at a young age (0- 5 years), a healthier weight might be maintained thereafter. The findings of this study can be applied to public health interventions which seek to reduce the rate of obesity among children. Public health interventions should target children at the preschool age where factors responsible for weight gain are likely to be found in the family and the home then at school environment.

*Highlights Digest. June 2008. High BMI in Childhood Creates Risk for Heart Disease Among Adolescents. Volume 7(2). Ref: Baker JL, Olsen LW, Sorensen TIA. Childhood Body-Mass Index and the risk of coronary heart disease in adulthood. The New England Journal of Medicine; 357(23): 2329-2337.

References

Gardner D., Hosking J., Metcalf B., Jeffery A., Voss L.D., Wilkin T.J. Contribution of Early Weight Gain to Childhood Overweight and Metabolic Health: A Longitudinal Study (EarlyBird 36). Pediatrics. 2009; 123(1):e67-e73.