In Scotland, almost a quarter of children are starting school at risk of being overweight or obese, with the poorest children at nearly 50% greater risk than the wealthiest. With the influx of cheap and convenient processed foods in our supermarkets, what was once considered a problem for the wealthy is now an issue for more disadvantaged families. Article 24 of the UN Convention on the Rights of the Child states that every child has the right to the best standard of health, including nutritious food. If a child is overweight or obese, it can lead to numerous long-term and short-term health issues, such as early-onset type-2 diabetes and coronary heart disease.

The Growing Up in Scotland (GUS) cohort of data is a long-term monitoring project with a specific focus on the early years (0-6.) A wide range of information has been collected about children, since they were 10 months old in 2004/5, as well as their families, including physical and mental health, home and family life and education.  

The goal was to perform analyses of this data to inform the design of obesity/overweight surveillance systems that can be used, not just in Scotland, but internationally. We looked to answer key questions including: 

At what specific ages would measuring height, and weight most effectively and efficiently identify children at risk of persistent obesity at ages 10 and 12?  

What underlying risk factors for child obesity could be used to accurately identify cases of concern, and intervene in a preventative way, before obesity develops? 

How do markers of family socio-economic status relate to child overweight and obesity? (Including child obesity unrecognised by parents?)  

Are any adverse and protective childhood experiences independent risk factors for obesity? 

As the first step in that necessarily long and deliberative process, we believe this study has demonstrated that an acceptable level of predictive validity for obesity at age 12 can be achieved very cost-effectively, using only a half-dozen predictor variables which are routinely collected before age 6 in many countries. These analyses will inform the design of future National Obesity Surveillance Systems for any similar setting—i.e. countries, mostly high-income, which have for some decades had a significant public health problem of child obesity.