Children who are prone to tantrums and emotional outbursts are more likely to become overweight - probably because their parents resort to the age-old method of placating them with sweets or chocolate bars.

A new study from America has shown that the temperament of a child plays a key role in forming their future shape. By looking at a group of 150 children from the day they were born until they were nine years old, researchers could see that those who suffered more tantrums were at greater risk. They also found that the way parents deal with flare-ups, and their own weight, also played a role.

Writing in the Journal of Paediatrics, researchers at Stanford University identified those children who were 'highly emotional' as being prone to being overweight.

'Parents faced with an emotional child who has tantrums over food may feed the child to reduce the frequency of tantrums,' they said.

This means that educating parents on how to deal effectively with a screaming toddler may both improve their behaviour and reduce the chances of them becoming tubby.

The study also showed that those with overweight parents were far more likely to become overweight themselves. Up to 64 per cent of children with overweight parents were themselves overweight. Of those whose parents had a healthy weight, just 16 per cent gained too many pounds.

Another factor appears to be sleep patterns. The study found that children who were overweight slept about 30 fewer minutes each day than their slimmer counterparts. This is probably because children who do less in the day are simply less tired at night.

Health experts are increasingly looking at the way parents behave as an indication of the child's future health chances. They are keen to see whether parental counselling courses can teach mothers and fathers to be consistent in the way they treat their children.

Using food to placate a child who is behaving badly has long been criticised but is an easy way out for parents frazzled by tantrums, or embarrassed in restaurants when a child starts to scream.

Obesity rates in England have tripled in the last 20 years, and it now costs the country £3.7bn a year. Three-quarters of adults are now overweight, with 22 per cent of them obese.

Earlier this year MPs called for more help to be made available to parents, including the introduction of a 'traffic light' system in stores to mark out healthy and unhealthy foods. Under the system, red would identify high-energy foods which were high in sugar and fat, amber would be medium energy and green would identify the healthiest options.

The Co-op supermarket chain already has such a system in place and Tesco has announced plans to test a similar scheme.

Later this year Health Secretary John Reid will produce a White Paper on Public Health. He said last month: 'We recognise that these issues are not just a matter for government - they involve individuals and the choices they make, as well as the food and leisure industry.'