We have developed several simple mathematical models of human body composition change that help elucidate the factors that determine the proportion of body fat versus lean mass change with weight loss or weight gain. These simple models have been used to analyze data from several published weight loss studies and allowed us to quantitatively link the physiological properties of substrate utilization to the long-term regulation of body composition. Furthermore, we used our simple models to delineate the limited applicability one of the most pervasive weight loss rules: that a cumulative energy deficit of 3500 kcal is required to produce one pound of weight loss. ? ? We have also developed a more complex model of human macronutrient metabolism and have conducted several validation studies using a variety of published data on the metabolic responses to overfeeding, underfeeding, and isocaloric changes in dietary macronutrients. We have recently developed a model of ketogenesis that was incorporated in the whole-body model in order to simulate the effects of low carbohydrate diets. The model is beginning to be deployed as a clinical research tool in collaboration with NIH clinical investigators to help design prospective studies as well as plan and track clinical weight management programs.

Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
2007
Total Cost
$177,280
Indirect Cost
City
State
Country
United States
Zip Code
Lieffers, Jessica R; Mourtzakis, Marina; Hall, Kevin D et al. (2009) A viscerally driven cachexia syndrome in patients with advanced colorectal cancer: contributions of organ and tumor mass to whole-body energy demands. Am J Clin Nutr 89:1173-9
Hallgreen, C E; Hall, K D (2008) Allometric relationship between changes of visceral fat and total fat mass. Int J Obes (Lond) 32:845-52
Hall, K D (2008) What is the required energy deficit per unit weight loss? Int J Obes (Lond) 32:573-6
Hall, K D; Hallgreen, C E (2008) Increasing weight loss attenuates the preferential loss of visceral compared with subcutaneous fat: a predicted result of an allometric model. Int J Obes (Lond) 32:722
Jordan, Peter N; Hall, Kevin D (2008) Dynamic coordination of macronutrient balance during infant growth: insights from a mathematical model. Am J Clin Nutr 87:692-703
Chow, Carson C; Hall, Kevin D (2008) The dynamics of human body weight change. PLoS Comput Biol 4:e1000045
Hall, K D; Bain, H L; Chow, C C (2007) How adaptations of substrate utilization regulate body composition. Int J Obes (Lond) 31:1378-83
Hall, Kevin D (2007) Body fat and fat-free mass inter-relationships: Forbes's theory revisited. Br J Nutr 97:1059-63
Hall, Kevin D (2006) Computational model of in vivo human energy metabolism during semistarvation and refeeding. Am J Physiol Endocrinol Metab 291:E23-37