Complementary feeding

Why and when to introduce new foods

Expanding an infant's diet serves several physiological functions simultaneously. First, it provides nutritional compensation: a growing organism requires more proteins, fats, and micronutrients than milk alone can provide. Second, the child begins to receive carbohydrates, proteins, and fats of plant origin. Third, functional training takes place — transitioning to solid food develops the chewing apparatus and adapts the gastrointestinal tract to new loads.

According to World Health Organization recommendations, for healthy, term infants with normal weight (and in the absence of maternal nutritional deficiencies), the standard time for introduction is at 6 months of age.

However, there is a practice of early start (from 4 months), which is applied according to strict medical indications:

• intrauterine growth restriction (IUGR);
• infant malnutrition (hypotrophy);
• pronounced nutritional deficiencies in the mother.

How to choose the first complementary food

The main rule states that the food chosen for the first introduction to new foods must have a high energy density. There is no strict, universal sequence for all children, but kefir, cottage cheese, or fruit purees are not recommended as starting foods. For a healthy six-month-old infant exclusively breastfed, gluten-free porridge or single-ingredient vegetable puree is the optimal choice.

The choice between porridge and vegetables is based on two approaches.

Basic approach (depends on the type of feeding):

• In exclusive breastfeeding (EBF), the start begins with cereal grains (porridge).
• In formula feeding (FF), the first food is vegetables.

Individual approach (depends on the clinical picture):

• Indications to start with porridge: underweight, anemia (decreased hemoglobin levels), unstable stools (tendency toward diarrhea).
• Indications to start with vegetable puree: overweight (paratrophy) and a tendency toward constipation.

Chronology of diet expansion

The logic of introduction is based on a gradual transition from single-ingredient, hypoallergenic foods to multi-ingredient ones.

1. 4–6 months (Start): Begin with cereals (for EBF). First come gluten-free grains (rice, corn, buckwheat), followed by gluten-containing ones (wheat, oats). Porridges are diluted with breast milk or formula, bringing the volume up to 150–200 g/day. When preparing at home during this period, 2–5 g of butter or vegetable oil is added.
2. 5–7 months: Vegetable puree is introduced (the start for FF). Begin with a single type, gradually expanding the composition to 3–4 types of vegetables. The daily volume is brought to 150–200 g.
3. 6 months: Introduction to fruits. First, juices are offered to the child, and after 2–3 weeks of successful adaptation, fruit puree is added (60–100 g/day).
4. 6–7 months (Protein load): Cottage cheese (30–50 g/day) and egg yolk (from 1/4 to 1/2 part) are included in the diet. Meat is introduced in stages: starting with meat-vegetable canned foods (where the meat share is 10–20%), then moving on to purely meat ones (up to 60% meat). The volume of meat puree is smoothly increased from 30 to 70–90 g per day.
5. 7–8 months: Unadapted fermented milk products (e.g., kefir) and combined fruit-cereal purees are added.
6. 8–9 months: The introduction of fish begins. Fish puree (often combined with vegetables) is given 1–2 times a week, 30–60 g at a time. Important: on these days, fish must strictly replace the meat puree.

The danger of cow's milk

Whole cow's milk is not recommended for children in the first year of life; its use is permitted exclusively at 1–3 years of age.

The pathogenetic rationale for this restriction lies in the effect of cow's milk protein fractions on the infant's body. They exert a direct damaging (pathological) effect on the immature intestinal epithelial barrier. This triggers the development of microdiapedetic bleeding — occult blood loss through the gastrointestinal tract. As a result, the child loses iron, calcium, and fats, and the adequate absorption of essential trace elements (copper and zinc) is impaired.

Class and exam questions

What else to study on this topic

• Pathogenesis of microdiapedetic gastrointestinal bleeding in infants.
• Features of dietary correction for food allergies in infants.
• Principles of medical nutrition in lactase deficiency.
• Nutritional algorithms for functional gastrointestinal disorders.

Other topics in "Chapter 3. Adaptation, Early Childhood Nutrition, Rickets"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.