The national obesity forum chairman, Colin Waine, said checks should be carried out at least once a year from a child’s first birthday because the early signs of obesity could be detected before school age.
His comments came after the Department of Health said official warnings could be sent to the parents of obese children as young as five.
Dr Waine said action was required at an even earlier age to instil good eating habits in children and their families.
He said: “Weighing children at five would be useful but it would be more logical to start measuring children on a yearly basis from one year old. The early signs of obesity can be detected before school.”
The doctor added that action to prevent childhood obesity should begin before birth with a greater emphasis on maternal nutrition.
“We should be doing more to ensure expectant mothers eat well and encourage them to breastfeed for six months. We also need to make sure mothers have the information and advice to provide their child with a balanced diet once they are weaned,” he said.
Currently, children in England and Wales are weighed at five and 10, but their parents are told the results only if they request them. Under the new government plans, parents could be handed the results automatically.
Childhood obesity has soared over the past decade, with 16.9% of boys and 16.8% of girls aged between two and 10 now classified as obese.
If current levels continue, about 60% of men, 50% of women, and 25% of children in the UK will be obese by 2050, according to a recent report by scientists.