Numerous studies have shown the importance of breastfeeding in the prevention of childhood obesity.

The importance of the first 1000 days of life – starting from the first day of conception – for the child’s health is widely discussed, the processes of development and growth are intense for such a short period, which is why a balanced maternal diet during pregnancy together with exclusively natural feeding from the first moments of the newborn’s extrauterine life are essential criteria for a harmonious development⁽¹⁾.

According to the World Health Organization (WHO), exclusive breastfeeding in the first six months of life with a continuation until the age of 2 years old and after this age, if the mother and child wish, is associated with a low risk of childhood obesity⁽²⁾.

Epidemiology

According to the WHO and International Obesity Taskforce (IOTF), in 2010 there were over 200 million overweight or obese children worldwide, and 42 million were children under 5 years old⁽²⁾.

If each child were exclusively breastfed for the first 6 months, with a continuation of up to 2 years old, 800,000 children would be saved from death each year⁽³⁾.

In 2012, only 38% of infants under 6 months of age were exclusively breastfed worldwide⁽⁴⁾.

The aim of the World Health Organization is to increase the rate of exclusive breastfeeding to 50% until 2025.

The benefits of breastfeeding

Breastfeeding defines the feeding of the newborn with exclusively breast milk in the first six months of life, being the safest, most efficient, easiest and cheapest way to feed an infant.

The secretory immunoglobulin A contains specific antibodies against bacteria, viruses, fungi and protozoa, the exclusively natural diet giving the newborn an intake of 0.5-1 g of IgAs. Lactoferrin have a role in iron transport, being also an anti-infective agent. Lipids have antiviral, antimicrobial and antiprotozoal properties. Oligosaccharides, with protection against thermostable enterotoxins, favor the development of bifidobacteria⁽¹⁶⁾.

Immunomodulatory factors play a role in decreasing the risk of terminal ileitis, increasing tone and decreasing the pain response⁽¹⁷⁾.

The composition of breast milk

Human milk is a biological liquid with a unique complexity, consisting of 87% water, 7% carbohydrates, 4% lipids and 1% protein. The energy of human milk is 70 kcal/dL, being significantly associated with the amount of fat in milk. Lipids are the group of macronutrients with the highest variability in the composition of breast milk (50-55%). The amount of lipids is inversely proportional to the amount of milk in the breast, at the beginning of sucking, when the breast is full; the quantity of lipids is small, they increase with the decrease in the amount of milk, towards the end of sucking, 98% of lipids being represented by triglycerides, the rest being represented by cholesterol, free fatty acids, phospho­lipids and sphingolipids^(8-10). Cholesterol is found in higher amounts in breast milk than in cow’s milk. The amount of fatty acids in human milk is influenced by diet and maternal nutritional status, exclusively in the natural diet, the newborn benefiting from the presence of omega 3 and 6 acids^(14,15).

Casein is a protein present in about 40% in breast milk. It contains less phosphorus compared to cow’s milk and is easier to digest. The rest are whey proteins (60%); alpha-lactoglobulin predominates in breast milk and whey proteins are easy to digest, which leads to a rapid gastric emptying; for this reason, naturally breastfed babies need, physiologically, more meals than those who receive artificial feeding^{(8,9,11,13-15)}.

Carbohydrates from natural food provide 35-40% of the total energy provided by breast milk. Lactulose is the main carbohydrate of human milk, being associated with the growth of the infant.

The amount of lactulose in breast milk is not influenced by the maternal diet and is the only source of galactose, with a major role in myelination and cerebroside synthesis, stimulating lactase synthesis, accelerating intestinal transit, having an antirotting and fermentative role, and promoting phosphor-calcic metabolism^(11,13). Proteins and carbohydrates are increased in the beginning of sucking.

Breast milk has a role in the formation of colic flora specific to the breastfed child, oligosaccharides being sources of probiotics.

Breast milk is the most hypomineralized milk. Phosphorus and calcium are found in lower amounts than in cow’s milk, but the Ca/P ratio of 2.12 leads to a higher absorption than the absorption of calcium from cow’s milk. Due to the load of 80-98 mOsm/L, breast milk loads the kidney much less osmotically⁽¹⁶⁾.

The average energy value of breast milk is 670 kcal/L, with variations between 640 and 723 kcal/L, with 5-7% proteins, 35-40% carbohydrates and 50-55% lipids⁽¹³⁾.

Studies

The studies have shown a healthier eating behavior among those who were breastfed compared to those who were fed on formula⁽¹⁾.

The duration of breastfeeding was associated with a decrease in the risk of childhood obesity. Thus, a meta-analysis showed a significant reduction in those who were breastfed for more than seven months (AOR=0.79; 95% CI; 0.7-0.88), observing the decrease of obesity risk in relation to the increase of the number of months in which the child was breastfed⁽⁴⁾.

McCrory et al. showed that being breastfed for between 13 and 25 weeks was associated with a 38% reduction in the risk of obesity at 9 years of age, while being breastfed for 26 weeks or more was associated with a 51% reduction in the risk of obesity at 9 years old⁽⁵⁾. Harder et al. found that each additional month of breastfeeding reduced the risk of obesity by 4%⁽⁶⁾.

A higher prevalence of obesity was demonstrated in those who have never been breastfed or have been breastfed for less than six months compared to those who have been exclusively breastfed for six months or more than six months. A study also showed that the Mediterranean countries have the highest prevalence rates of obesity (more than 16%)⁽⁷⁾.

In a study conducted in Oregon, the authors followed for two years all children born in 2009 and showed that, for each additional week of breastfeeding, the probability of the child being obese at the age of 2 years old decreased by 0.82%⁽¹⁸⁾.

Conclusions

The concern of health experts is closely linked to the fact that most of those affected by this malnutrition are prone to obesity in adulthood, where the occurrence of noncommunicable chronic diseases and psychiatric disorders caused by obesity lead to huge costs to the health system.

Breast milk is the best food for the human species, perfectly adapted to the needs, always at hand, present at the ideal temperature, having antimicrobial, antitumor and antiobesity protection, being a growth factor and an emotional stabilizer, with nutritional balance. Therefore, breast milk is the gold standard of the newborn diet and for the infant, subsequently representing the completion of the small child.   

Conflict of interests: The authors declare no con­flict of interests.