Toddlers need plenty of fat. And it's lack of exercise that usually causes obesity in older children
If your toddler prefers chips to carrots, do not despair. He or she is probably following his instinct for the high fat energy-dense foods his growing body needs, according to a new report. Too many middle class, well-educated parents, it says, are feeding small children the fashionable, low-fat, high fibre foods they eat themselves - and by doing so are putting them at risk of stunted growth, learning difficulties, diabetes and heart disease.

The report has been produced by the "Butter Initiative" sponsored by Anchor, which clearly has its own axe to grind. But there is independent evidence that "muesli-belt malnutrition" does exist: last year, a study of more than 1,000 mothers across England found that four-fifths were putting small children on a "nursery starvation diet" of vegetable and fruit purees, and low fat yoghurts rather than traditional foods such as buttered potatoes and apple crumble. Recently, there have been reports of some weight-conscious mothers diluting their babies' milk.

Dietitians blame the problem of children being fed too little fat and too much fibre (a problem limited, it seems, to the more health-conscious South) on parents applying guidelines for adults to small children, in the hope of preventing cardiovascular disorders and other diseases of adulthood. There are also worries about children getting fat. Yet there is little evidence that fat in childhood triggers ill-health later; obesity in children is more likely to be caused by lack of exercise.

Small children need more fat than the rest of us partly because, on a weight-for-weight basis, they need far more calories to maintain growth. They also have small stomachs and cannot eat much at one time. . Foods such as full fat milk and cheese are not only calorie-dense, they also provide crucial fat-soluble vitamins such as A and D. Given too much high fibre food such as muesli (great for plump grown-ups) small children will feel full without getting the calories their bodies need.

So what should worried - and confused - parents do? The ideal adult diet is often presented as a "food pyramid", in which carbohydrates form the base, with fats as a small triangle at the top. Those with very small children (under two) should think of this pyramid as the other way up, with 50 per cent of energy coming from fat: they can include butter or unsaturated spreads, full fat milk and yoghurt, and meat. Between two and five, children can slowly begin to adapt to a more adult diet: after two milk can be semi-skimmed if a child is eating well. By about five, average levels of fat intake should be down to about 35 per cent. An adolescent will still need plenty of calories for growth spurts but can safely cut down on fat intake.

Variety is the key: the occasional chocolate cake, or portion of chips is fine, and of course fruit and vegetables are important, both for vitamin C and to help a child establish good eating patterns. But for pre-school children, a major concern is to ensure they get enough calories. A plain digestive biscuit, for instance, contains about 70 calories, about the same as an apple. A small child in need of a quick mid-morning snack may not be able to eat a whole apple but he or she will almost certainly manage a biscuit.

If your child is healthy and growing then you're probably getting it right.