A child health expert says the speed at which a baby gains weight in its first few months can determine whether it is at risk of obesity in later life.
Tam Fry, chairman of the Child Growth Foundation, said the crucial years to check for signs a child could be at risk was when they are aged between one and four.
He said health visitors have a major role to play in the prevention of childhood obesity and has called for greater investment in primary care staff.
Mr Fry added that babies should be regularly weighed and measured against growth before they reach their first birthday but most are not because of time constraints on health visitors and fewer staff.
Scotland has one of the highest levels of child obesity in the Western world, with 22% of six-year-olds classed "overweight".
Mr Fry, spokesman for the National Obesity Forum, says Scotland is dealing with two epidemics, childhood obesity and maternal obesity, and says women should ideally aim to be a healthy weight before they conceive.
He has also called for high school pupils to be given lessons in parenting, including healthy eating classes.
Mr Fry said: "The most important year in a child's life is the first and it is the speed at which they put on weight that is a harbinger for the future. You can't just measure them at the end of the first year. Until Scotland has a surveillance system that will spot the early signs of unhealthy weight gain in pre-school then, in the opinion of the Child Growth Foundation and UK National Obesity Forum, it will never make inroads into one of its major health problems."
A spokeswoman for NHS Greater Glasgow and Clyde said health visitors already contributed to tackling obesity in children by identifying families who would benefit from weight management support.