There is much public hand-wringing about our nation of supposedly fat children. But the picture is not yet as gloomy as we are led to believe.

About one in five children is obese or overweight, according to the latest National Diet and Nutrition Survey. We sometimes forget this means that four out of five are a healthy weight!

However, since two-thirds of adults are overweight or obese and fatness tends to run in families, many more children are at risk of following suit. So there is no room for complacency.

Some groups appear to be at greater risk, such as people of Asian origin, low income earners and people living in Scotland and Wales. These variations in obesity in children contribute to the health inequalities seen in adulthood, like diabetes and heart disease.

Children with established obesity may require medical intervention, but the aim for most overweight children is to help them maintain their weight and allow them to “grow into it” as their height increases. Curtailing weight gain requires a lot of support from parents, carers and health professionals to choose a healthier diet and to become more active. But children who are not overweight also need support to keep them healthy.

The fact is the world we live in makes excess weight gain the “default situation”. Each of us needs to take steps to avoid it. Many factors contribute to this “obesogenic” environment, where opportunities to consume excess calories far outweigh opportunities to expend energy.

Children cannot be expected to understand the long-term effects of dietary and lifestyle choices on their health. Parents must take initial responsibility for introducing them to a healthy lifestyle. However, parents also need support to develop an environment that will help them make sensible dietary choices and allow their children to be physically active in safe surroundings.

Our efforts should be focused on working together to create an environment that will minimise or prevent the risk of children becoming overweight in the first place. Schools need to develop partnerships with parents and children, offering cost-effective healthy eating options and finding time in the curriculum for physical activity. At home we need to overhaul lifestyles, encouraging family meals. Food manufacturers, advertisers and marketers need to find ways of fostering a society in which exercise and healthy eating is fashionable.

By working together we can make a difference to the weight and health of future generations, and keep this myth from becoming a reality.

Dr Toni Steer is a nutritionist at the Medical Research Council’s Human Nutrition Research unit, Cambridge. This is the first of 10 myths to be dismissed this term.

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