Obesity in Toddlers and Young Children: Causes and Consequences

The rapid rise in obesity in toddlers and young children (aged 0-5 years) is a major concern for public health globally. Understanding risk factors for obesity in the early years is therefore fundamental to help guide parents, educators, and health care professionals caring for young children and to develop preventative strategies. Most research has focused on biological risk factors, which can be broadly categorized as genetic predisposition, poor diet (and the behaviors that influence excessive food intake), insufficient physical activity, and the role of developmental factors in early life that influence long-term health. The latter includes establishment of dietary habits and dietary patterns in young (preschool) children and the effect of a high protein intake on the increasing risk of later obesity. Other risk factors particularly relevant to young children include inadequate sleep, high consumption of sugar-sweetened drinks, and large food portions. Understanding the causes of obesity in preschool children is particularly important in view of long-term detrimental consequences of obesity in this age group on the risk of obesity and cardiometabolic disease in adults. The present chapter reviews causes of obesity in preschool children and its consequences for long-term health, focusing particularly on modifiable nutritional risk factors.