CHILD AND ADOLESCENT NUTRITION
A. Nutrition in the first year of life
This stage presents two major characteristics:
- Maximum growth and physical development. The weight of the newborn increases 2 x fold at 5 months of age and 5 x fold at 1 year of age, increasing body length in about 25-30 cm. This accelerated development gives rise to increased energy and nutrition needs which will gradually decrease over time as the child's grows.
- Immatury of food processes, that develop completely over the first two years of life (dentition, coordination in deglution, acid secretion into the stomach and pancreatic secretions).
Based on the above information, this period is considered to be the "breastfeeding period". The mother's milk is the ideal nutritional source because:
a) It satisfies the energy and nutritional needs of the infant (except for vitamin K and vitamin D that must be taken as supplements). It has a high content of essential amino acids, low salt content, and excellent bioavailability of calcium, phosphorous, magnesium and iron.
b) It provides immunoglobulin A, lactoferine and lysozyme from the mother, which confers the infant with protection against GI infections.
c) Lesser incidence of atopic dermatitis and allergy (sensitivity) to cow's milk.
d) It provides growth factors and gastrointestinal hormones that favour the maturation of the newborn's gastrointestinal tract.
e) It establishes an optima relationship between mother and infant with greater affective bonding.
When the mother's milk needs to be replaced, there are several artificial options (formulas made of cow proteins in healthy children) for feeding infants and follow-on formulas).
After the 6th month, the mother's milk or infant formulas do not completely satisfy the growing infant's nutritional needs. It is at this time, when the progressive introduction of solids foods, adequate for the infant's age, is introduced (either as pureed foods or grinded).
Nutritional supplements needed in the first year of life to meet RDAs include:
Vitamin D: Mother's milk does not cover the needs for this vitamin and thus a supplement of 10 mcg/day is recommended. After the 6 months of age, if there is adequate of exposure to sunlight, the supplement may be decreased.
Iron: Iron supplement can be given to exclusively breastfed infants during their first six months of life.
Fluoride: Dental calcification stars in the uterus. Due to the low content of fluoride in mother's milk, a supplement if 0.25 mg7day is suggested in exclusively breastfed children.
B. Nutrition between 1 and 3 years of age
This is a transition period between the breastfeeding period and stable development after the age of 3 years. The child starts to adopt the family's dietary habits with appearance of the first dislike for some foods.
The general indications are:
Food groups are similar to those needed in the first year. The intake of milk products should no less than 500 ml of milk or its equivalent in milk derivates. It is suggested to use follow-on formula or enriched formula. Meat and fish should be lean and cooked with a scanty amount of oil. It is important to control the intake of sweets and junk food.
If a varied diet is followed, supplements are not necessary, except for fluoride in the case of consumption of low-fluoridated water.
C. Nutrition after the age of 3 years
After the age of 3 years, the child enters a period of life divided into preschool period (4 to 6 years), school periods (7-14 years) and adolescence.
The nutritional needs corresponding to these age periods are:
a) Protein intake: 10-15% of the total calories
b) Carbohydrates: 50-55% of the total calories
c) Fiber: 8-25 g/day
d) Fat intake: 35%
Very low fat diets are not recommended because they can negatively affect our body and cause liposoluble vitamin deficiency (A, D, E and K). It is suggested not to introduce diets with an excessive content of salt.
After the age of 3 years, the diet must be supplemented with 0.25 mg fluoride up to 6 years, and then onwards with 0.50 mg until the child grows into an adult.
Foods must be distributed into 5 meals as follows: 25% at breakfast, 25-30% lunch and dinner and 15-20% as a snack. Good eating habits should be promoted both at home and at the school. This will prevent the development of obesity and associated diseases in the future and it will favour physical activity.