Fats in limited quantity are necessary for proper functioning of human body. High levels of saturated fat in the diet can increase risk of heart and circulatory diseases, such as coronary heart disease, heart attacks, angina and stroke.

Saturated fat is found in dairy and red meat. 30g saturated fat in a day is enough for the average man and 20g saturated fat a day is enough for the average woman. Children aged 5-10 should eat no more than 20g of saturated fat per day. Recent data showed that children aged five have higher level of fat.

The Government's Food Standards Agency said that children should be stopped from drinking full-fat milk from the age of two to prevent clogged arteries and heart disease in later life.

Normal full-fat milk has 3.5 per cent saturated fat. Semi-skimmed has 1.5 per cent. Skimmed milk has only trace levels.

FSA nutrition Chief Dr Rosemary Hignett said: 'For small children, up to the age of two, it is particularly important to have a sufficient level of fat in the diet. But as we move to older age groups, our concerns turn to them not becoming obese and not starting to build up clogged arteries.'

She added that after that age of two, it is perfectly fine to start moving to semi-skimmed and 1 per cent milk.'