Child obesity and early nutrition
Obesity is an excessive body fat accumulation that presents a risk to health. For children under 5 years old, overweight and obesity are defined as being 2 or 3 standard deviations above the median of the WHO growth standards. The incidence of overweight children under 5 years increased from 31 million in 1990 to 41 million in 2016.
The repercussions on health and quality of life are immediate and can have an impact along the whole lifespan. Children affected by obesity have lower educational attainment and more psychosocial problems like poor self-esteem, anxiety and depression. In addition, the likelihood of being obese as an adult is increased, as it is the risk of non-communicable diseases like type 2 diabetes, cardiovascular diseases, some types of cancer and musculoskeletal disorders.
Consumption of sweetened beverages, energy-dense diets and inadequate physical activity are determinant in the development of childhood obesity, but complex interactions between the child, the family and the community play also a central role. Young children depend on the food that is made available to them by their caregivers, and they mimic parental behaviours from very young age. In turn, family’s diet and physical activity are influenced by their community; for example, by the availability of healthy food vendors and sport facilities. Because of this, successful interventions to prevent childhood obesity must involve parents, schools and community.
Opportunities for obesity prevention by early life interventions
Early life factors can shape the risk of obesity and other non-communicable diseases. The developmental origins of health and disease hypothesis (DOHaD) postulates that experiences during critical periods of development have consequences on short and long-term health.
Epidemiological studies have established an ‘U’ shape relationship of obesity risk and birth weight, which is a proxy of nutrition during the intrauterine period. Low birth weight can be the result of maternal undernutrition, placental insufficiency, or other factors that limit the nutrients available to the developing foetus. On the other hand, maternal obesity, excessive weight gain during pregnancy or gestational diabetes can result in excessive nutrient transfer and high birth weight.
Besides its numerous benefits for infant and maternal health, breastfeeding has also been associated to decreased risk of obesity. Human milk composition adapts to the specific needs of the growing infant and contains bioactives that contribute to organ maturation and microbial colonization. In addition, breastfeeding may support the self-regulation of food intake.
Complementary feeding period
During the complementary feeding period, children have their first experiences with different foods and textures. Research has shown that food habits established during infancy can track into childhood and adolescence. Repeated exposure to a variety of nutritious foods including fruits and vegetables will maximize the likelihood of consuming them as part of a healthy diet later in life.
Interventions during early life have the potential to prevent childhood obesity. Efforts should be focused on optimizing nutrition and weight gain during pregnancy, early detection and management of gestational diabetes and promotion of breastfeeding. In addition, support must be given to parents to introduce a wide variety of healthy foods and promote regular physical activity.