Most of the essential nutrients are present in a wide variety of foods and so varied eating is the key to a successful vegetarian diet for children. Because vegetarian sources of protein are often bulky and contain high fibre, younger children run the risk of filling up before they have taken in enough calories. Also high fibre content can make it harder for the gut to absorb iron and calcium from other foods. To avoid this problem, encourage them to eat plenty of nuts and lower-fibre cereals with not too much reliance on fruit and vegetables. Include fruit or fruit juice because vitamin C helps iron absorption.