Pediatric obesity-Long-term consequences and effect of weight loss

Abstract

Childhood obesity is, according to the WHO, one of the most serious challenges of the 21st century. More than 100 million children have obesity today. Already during childhood, almost all organs are at risk of being affected by obesity. In this review, we present the current knowledge about diseases associated with childhood obesity and how they are affected by weight loss. One major causative factor is obesity-induced low-grade chronic inflammation, which can be observed already in preschool children. This inflammation-together with endocrine, paracrine, and metabolic effects of obesity-increases the long-term risk for several severe diseases. Type 2 diabetes is increasingly prevalent in adolescents and young adults who have had obesity during childhood. When it is diagnosed in young individuals, the morbidity and mortality rate is higher than when it occurs later in life, and more dangerous than type 1 diabetes. Childhood obesity also increases the risk for several autoimmune diseases such as multiple sclerosis, Crohn's disease, arthritis, and type 1 diabetes and it is well established that childhood obesity also increases the risk for cardiovascular disease. Consequently, childhood obesity increases the risk for premature mortality, and the mortality rate is three times higher already before 30 years of age compared with the normal population. The risks associated with childhood obesity are modified by weight loss. However, the risk reduction is affected by the age at which weight loss occurs. In general, early weight loss-that is, before puberty-is more beneficial, but there are marked disease-specific differences.

Keywords: cardiometabolic disease; inflammation; obesity comorbidities; pediatric obesity; weight loss.

Fig. 1

Diseases and conditions caused or aggravated by obesity during childhood and adolescence. Childhood obesity is a systemic disease and almost all organs in the body are potentially affected.

Fig. 2

Many different factors contribute to the long‐term effects of childhood obesity. They interact in a complex pattern and it is difficult to identify one specific mechanism responsible for one long‐term consequence. The low‐intensity inflammation caused by obesity in young children already contributes to many obesity‐associated diseases.

Fig. 3

Effect of severe adolescent obesity and weight loss on lung volume, posture, and gynecomastia in adolescents. (Panel a) Adolescent before and 2 years after gastric bypass surgery and 40 kg of weight loss. The lung volume is markedly restored. (Panel b) One year with 30 kg weight loss as an effect of successful lifestyle support. The posture is normalized and the lipomastia is reduced but the gynecomastia remains despite weight loss. Written approval obtained from the patient to use the photos of him before and after weight loss presented in Fig. 3.