I'm confused about whether I should be giving my children full-fat, semi-skimmed or fully skimmed milk. My children are 18 months, 4 and 7 years old. Help!

I can understand your confusion because, officially, your children are all advised to have different types of milk, which is a bit of a nuisance for you as your fridge will be full of bottles or cartons. My advice, and it's backed by the Food Standards Agency, is that your toddler should have full-fat milk up until two years of age. From then until they are 5, children should stick with semi-skimmed and, once they are over 5, you can give them fully skimmed.

The reasoning behind these gradual steps is that before they are two years of age, toddlers do not tend to eat large quantities of food at one go. So, while you need to give them a healthy, balanced mix of foods including protein (meat, fish, eggs, milk and cheese or tofu, for instance), carbohydrates (bread, pasta, rice, potatoes, breakfast cereals) and fruits and vegetables, they need to be the “normal” versions that ensure sufficient calories and all the important nutrients are consumed.

Over two years old, children's tummies are getting more able to cope with slightly larger meals and snacks, allowing the introduction of lower-fat versions of dairy foods such as semi-skimmed milk. This step begins gradually to cut the amount of saturated fats eaten, a need highlighted in a new Food Standards Agency campaign to encourage us to eat less of these animal-based fats that raise cholesterol.

By the age of 5, fully skimmed milk is allowed to further cut saturated fats with the assumption that all nutrient and energy needs can be met through eating sufficient amounts of other healthy foods.

While we are at it, it is worth looking at other food groups that can give parents concern regarding children. When it comes to fruits and vegetables, from the age of 1 children should be building up to five portions a day, remembering that one portion is roughly the amount that they can hold in their hand. This may for instance be only two grapes, a few carrot batons or smallish slices of apple. Given that little hands grow, portion sizes grow too as they get older.

High-fibre foods are an interesting topic. While nobody would advocate sprinkling bran on to toddlers' and children's foods, the British Dietetic Association Paediatric Group does say that wholegrain foods are acceptable from the age of 1. In other words, wholemeal bread, brown rice and pasta can be gradually introduced.

As for what we need to avoid, toddlers should not be given undercooked or raw eggs, to avoid the risk of salmonella - but note the British Heart Foundation's recent advice that eggs no longer need to be limited for fear of cholesterol.

Whole or chopped nuts are not advised until the age of 5 to avoid the risk of choking. It's best to avoid shark, swordfish and marlin as they contain relatively high levels of mercury that may affect a developing nervous system. Added salt and processed foods should be kept to a minimum in a child's diet, as should sugary foods and drinks.

Other healthier options for children

If wholegrain foods are not palatable for your children, try things such as mixing white and brown rice, and bread such as Kingsmill 50/50, which looks white but contains 50 per cent wholemeal flour. Switching to lower fat milk from the age of two, and fully skimmed from five is especially good for girls. According to the Institute of Medicine of the National Academies in America it will reduce exposure to dietary pollutants that are carried in animal fats.