Complementary feeding is giving infants other foods or fluids than breastmilk. Complementary food is any food other than breastmilk given in the complementary feeding period. Complementary foods can be especially prepared for the infant or can be the same foods available for family members, modified in order to meet the eating skills and needs of the infant. In the first case, they are called transitional foods, and in the second case, there is no specific nomenclature.
From the nutritional viewpoint, the early introduction of complementary foods can bring some disadvantages, since these foods, in addition to replacing part of breastmilk, even when breastfeeding frequency is maintained, often have a lower nutritional value than breastmilk, for instance, foods that are extremely diluted. A shorter duration of exclusive breastfeeding does not protect infant growth so well as exclusive breastfeeding for six months does, and neither does it improve it. After the sixth month, the replacement of breastmilk with complementary foods is less problematic. Moreover, the early introduction of complementary foods shortens the duration of breastfeeding, interferes with the uptake of important nutrients found in breastmilk, such as iron and zinc, and reduces the efficiency of lactation in preventing new pregnancies.
More recently, the early introduction of complementary foods has been associated with the development of atopic diseases. Exclusive breastfeeding minimizes the risk of asthma and this protective effect seems to persist for at least during the first decade of life, which is particularly evident in children with a family history of atopic diseases.
Exclusive breastfeeding also seems to protect against the development of type 1 diabetes mellitus. It has been described that early exposure to cow’s milk (before the fourth month) can be an important determinant factor for this disease and that it can increase the risk for diabetes by 50%. It is estimated that 30% of the cases of type 1 diabetes mellitus could be avoided if 90% of the infants aged up to three months were not fed cow’s milk.
When infants exclusively breastfed for six months do not develop properly, before considering the introduction of complementary foods, a careful assessment should be made to verify whether they are not ingesting too little breastmilk due to a poor breastfeeding technique, which leads to improper emptying of the breasts and, consequently, to a low milk production. In these cases, the usual recommendation is that mothers receive instructions and support so that the baby can increase the intake of breastmilk and complementary feeding is not introduced unnecessarily. One should recall that the current growth curves are predominantly based on infants fed industrialized milk and that the growth of healthy breastfed infants aged between three and nine months often is smaller than that of non-breastfed infants
This, however, does not imply any functional disadvantage
Characteristics of proper complementary feeding
A proper complementary feeding consists of foods that are rich in energy and in micronutrients (especially iron, zinc, calcium, vitamin A, vitamin C and folates), free of contamination (pathogens, toxins or harmful chemicals), without much salt or spices, easy to eat and easily accepted by the infant, in an appropriate amount, easy to prepare from family foods, and at a cost that is acceptable by most families
How to introduce complementary foods
The recommendation is that new foods be gradually introduced, one at a time, every three to seven days. It is common for infants to reject new foods, but this should not be interpreted as permanent aversion to that food. On average, infants need to be exposed to a new food eight to 10 times until they accept it well. Breastfed infants tend to accept new foods more easily than non-breastfed ones, because via the breastmilk, they are exposed to different flavors and scents very early on, which vary according to the maternal diet. Thus, infants are introduced to the family eating habits from the moment of birth (probably during the intrauterine life too). Improper food consistency compromises the appropriate intake of nutrients by the infant. Therefore, at the beginning of complementary feeding, the foods should be especially prepared for the infant. The foods should be initially semi-solid and soft (in the form of a puree), and should be crushed, never sifted or blenderized. Soups and soft foods do not provide enough calories to meet energy requirements of infants and are therefore not recommended. Food consistency should be gradually improved, considering the infant’s eating skills. At eight months, the infant can be offered family foods, provided that they are crushed, shredded, chopped or cut into small pieces. At 10 months, the infant can eat grain foods, otherwise, he/she will be at greater risk for eating disorders at 15 months.
At 12 months, most infants can eat the same foods their family eats, provided that these foods have an appropriate energy content and consistency. After that, the offer of semi-solid foods should be restricted, and sharp foods and/or foods with a hard consistency should be avoided (e.g.: raw carrots, nuts, grapes), as they can make infants choke.
Complementary foods should be given using a spoon or glass, which are well accepted by infants. Baby bottles should be avoided because, in addition to being an important source of contamination for the infant, they interfere with oral dynamics and may cause “nipple confusion” especially during the establishment of breastfeeding, exposing the infant to a greater risk of early weaning. One should recall that the use of baby bottles is not necessary during the baby’s growth.