Early mortality in adulthood has been shown to be nearly double in those who had been obese in childhood, and is most frequently associated with heart disease. Birth weight tends to correlate with the mother's degree of obesity. Consumption of greater quantities of food than the recommended norm is not a major factor. Instead, the type of food eaten may be important. The most common foods for children under 5 in the UK in 1997 were biscuits, white bread, chips and soft drinks. In French children, obesity has been linked to overeating protein in childhood.
In 1997 25% of American children were overweight, of which half dangerously so. This is the heaviest they have been since recordkeeping began. Obesity in children appears to be dramatically increasing in western-style countries. In Greece and France there are twice as many overweight children as 10 years ago, and in the USA as 30 years ago.
Weight increase is related to greater consumption of fatty fast food and lower consumption of fruits and vegetables, abetted by television advertising of fast food, and less exercise. The drop in exercise is in turn due to unsuitable play facilities, parents' fear of letting their children out alone, and less active forms of children's recreation, such as television and computer games.
Children of overweight parents are 3 times more likely to be fat than those with slim parents. The relapse rate among fat children is high, with half regaining the lost weight. If a child is fat at age 7, he will probably remain so.