ENERGY EXPENDITURE DURING RE-FEEDING AND ENERGY IMBALANCE

ENERGY EXPENDITURE DURING RE-FEEDING AND ENERGY IMBALANCE

 Perturbations in energy balance underlie the most common public health nutrition problems today. In the United States, 68% of adults and 35% of children are now overweight or obese. The prevalence of obesity is also increasing in developing countries, where under nutrition has traditionally been the primary nutrition challenge and remains prevalent. For example, the prevalence of obesity has increased recently in both Brazil and China, especially in urban areas but also in very low - income families such as those living in shanty towns. In addition to being associated with increased risks of type 2 diabetes, osteoarthritis, angina, and hypertension, obesity is also associated with premature death and increased health care costs. The estimated number of deaths attributable to obesity in the United States alone is ∼ 300,000 per year.  The excess weight gain that accumulates in obesity results from energy intake exceeding energy expenditure over a considerable period of time and has both genetic and environmental origins. This positive energy balance can occur because energy expenditure is low or energy intake is high, or a combination of these two factors. The importance of energy expenditure is suggested by several prospective studies showing that low energy expenditure is a risk factor for excess weight gain, and mechanistically may result from the effects of energy expenditure on both energy requirements and insulin sensitivity. In addition, the fact that excess energy intake is important, at least in the United States, is suggested by national survey statistics showing that per capital energy availability (adjusted for spoilage and waste) has increased over the past 20 years.