Journal Issue: Childhood Obesity Volume 16 Number 1 Spring 2006
Introduction
The increase in childhood obesity has gained the full attention of health care professionals, health policy experts, children's advocates, and parents. All are concerned that today's overweight and obese children will turn into tomorrow's overweight and obese adults, destined to suffer from all the health problems and health care costs associated with obesity. In this essay, we document trends in children's obesity and examine the underlying causes of the obesity epidemic.
We begin by discussing definitions of overweight and obesity, noting some potential problems. We document trends in adult and childhood obesity, both worldwide and in the United States, over the past three decades, paying particular attention to the timing of the increase in obesity. We preface our analysis of obesity's causes with a brief review of research on children's energy intake and energy expenditure and on what affects children's “energy balance.” Research findings support the idea that children who eat more “empty calories” and expend fewer calories through physical activity are more likely to be obese than other children. Finally we examine how the environment in which children are raised might have changed over the past three decades and how these changes might have upset the energy balance equation. Have changes in the food market, in the built environment, in schools and child care settings, and in the role of parents contributed to increased obesity? In particular, we examine whether the timing of the changes in children's environments coincides with the timing of the increase in obesity, making it likely that those changes are driving the increase in children's obesity rates.
