ProteinProtein consists of building blocks called amino acids. There are two types of amino acids: essential and non-essential. Essential amino acids must be obtained directly from food, while the body can produce nonessential amino acids from other sources. Therefore you need to make sure that your baby's diet contains enough essential amino acids (see "key protein foods", left).Why Your Baby Needs ItProtein is one of the most important nutrients for helping the body build and repair muscles, tissues, hair, and organs, and maintain an effective immune and hormonal system. Considering how fast babies grow during their first year, this is definitely one of their key nutrients.How To Make Sure Your Baby Gets ItAn adequate intake of protein, in particular, should be ensured during weaning. This will be easy to achieve if you aim to feed your baby a diverse diet by the time he is 9 months old. "If your baby is regularly consuming meat, fish, eggs and reasonable quantities of milk he is unlikely to be protein deficient" (UK Department of Health). If you are feeding your baby a vegetarian diet, you do need to pay attention to make sure that he eats enough protein-rich foods. Most plant foods are low in protein compared with foods of animal origin (with the exception of soya products), and the proteins from any single plant, unlike animal proteins, do not contain all the essential amino acids. This is why it is important to feed your baby a mixture of plant foods to help make sure that the complete range of essential amino acids is provided. Mothers wishing to offer their baby a vegan diet should seek specialist advice from a state-registered dietitian.Key Protein Foods(These foods are not all suitable for babies in all age groups)Protein Foods Providing All The Essential Amino Acids Include:- Meat, such as chicken and lamb- Fish, such as salmon and tuna- Dairy products, such as Cheddar cheese and yogurt- Eggs- Soya products, such as tofu, soya beans, and soya cheese.Good Vegetarian Protein Sources Include:(These do not contain all of the essential amino acids. However, in combination they can for instance, vegetable burgers served with rice).- Beans and pulses, such as chickpeas, beans, lentils, and butter beans- Cereals and grain foods, such as rice, pasta, oats, and nut-free muesli- Finely ground nuts, such as hazelnuts and almonds, and smooth nut butters (do not give nuts to babies if there is a family history of food allergies).- Ground seeds, such as sunflower seeds, and sesame seeds.IronThere are two main types of iron in food - haem iron from lean red meat and non-haem iron from plants sources, such as vegetables, finely chpped dried fruits, and finely ground nuts.Iron is needed for healthy blood and muscles. A lack of iron can lead to a common form of anaemia. A significant number of babies under 12 months do not achieve a good iron intake. It is very rare for babies to get too much of this mineral because they are unable physically to eat large quantities of it. (For example, the RNI for babies 4 to 6 months old is 4.3mg a day; 100g beef provides 3.1mg of iron.)How To Make Sure Your Baby Gets ItAt birth, babies born at term (as close to 40 weeks as possible) need only a small amount of iron because they have laid down stores that will last them for 6 months.The level of iron in breast milk is low, but since about 50 per cent or more of it is absorbed - which is a high rate of absorption for iron - this makes an important contribution for your breastfed baby during early weaning. Many formula milk powders are fortified with iron. The amount of iron contributed from breast and formula milk by the time the baby is 6 months old is insufficient to meet his increasing needs.One of the main functions of weaning is to increase your baby's iron intake. A large number of babies under the age of 12 months do not achieve the recommended level due to late weaning and inappropriate foods.Babies, like adults, find it easier to absorb haem iron. They are capable of absorbing 20 to 40 per cent of the iron from meat and only 5 to 20 per cent of the iron available from vegetable sources. Consequently, you will need to feed your baby a good variety and quantity of vegetables to provide him with a good supply of iron. The absorption of iron is enhanced by the presence of adequate vitamin C in the diet.Key Iron Foods(These foods are not all suitable for babies in all age groups) Red meat, such as beef and lamb Eggs Beans including baked beans Tofu (a soya bean product) Oily fish, such as tuna, mackerel and sardines Pureed or finely chopped dried fruits, such as unsulphured apricots, raisins and prunes Wholegrain cereals and bread Finely ground nuts (do not give nuts to babies if there is a family history of food allergies). Green vegetables, particularly broccoli and spinachAvoid giving your baby foods containing tannin or caffeine as they will inhibit iron absorption.