Submitted to: Trade Journal Publication
Publication Type: Abstract Only
Publication Acceptance Date: 6/14/2006
Publication Date: 8/28/2006
Citation: Butte, N., Christiansen, E., Sorensen, T. 2006. Energy imbalance underlying the development of childhood obesity in Hispanic children [abstract]. Obesity. 14:A68.
Technical Abstract: Childhood obesity arises from dysregulation of energy balance; however, the energetics for the development of childhood obesity are poorly delineated. We therefore developed a mathematical model based on empirical data and current understanding of energy balance to predict the total energy cost of weight gain and obligatory increase in energy intake associated with weight gain in children and adolescents. One-year changes in weight and body composition, and basal metabolic rate (BMR) were measured in 494 Hispanic children, ages 5-19 y. Fat-free mass (FFM) and fat mass (FM) were measured by DXA, BMR by respiration calorimetry, and sexual maturation by Tanner stages. Model specifications and constants included: body mass is equal to FFM plus FM, each of which has a specific energy content, cffm (1.07 kcal/g FFM) and cfm (9.25 kcal/g), and specific basal energy expenditure, kffm and kfm. The efficiency of converting energy is estimated for FFM (0.42, effm) and FM (0.85, efm). Total cost of weight gain is equal to energy storage, conversion energy for tissue synthesis plus energy expenditure associated with increased body mass at a physical activity factor equal to 1.75. Obligatory increase in energy intake is equal to total cost of weight gain, corrected for thermic effect of food (10%). Sex- and Tanner stage-specific values for kffm and kfm were indicated. Fraction of fat in added tissue (fr) was dependent of sex and Tanner stage, but not body mass. Rates of weight gain were significantly higher in overweight boys and girls (P=0.001). Total cost of weight gain and obligatory increase in energy intake are presented. Halting the development of childhood obesity in Hispanic children and adolescents will require a sizable decrease in energy intake or reciprocal increase in physical activity.