title: Metabolism of mice and men:  mathematical modeling of body weight dynamics.
abstract: OBJECTIVE
  Dynamic interrelationships between food intake, energy expenditure, energy partitioning, and metabolic fuel selection underlie changes in body weight and composition. A quantitative understanding of these interrelationships is becoming increasingly important given the rise of the worldwide obesity epidemic and the widespread interest in weight management. This review describes how mathematical models offer a quantitative framework for integrating dynamic physiological and behavioral data underlying body weight dynamics in both humans and mice.
  
  
  RESULTS
  Mathematical models have provided important insights regarding the drivers of the obesity epidemic, how metabolism adapts to different diets, the predicted magnitude and variability of weight change, and why mouse models have obesity phenotypes. Because mathematical models are constrained by conservation laws, they can also be used to infer physiological variables that are difficult to measure directly.
  
  
  CONCLUSIONS
  Mathematical models can help improve our understanding of the dynamic energy and macronutrient imbalances that give rise to changes in body weight and composition over time. The model development process can also highlight important knowledge gaps and model simulations can help design and predict the results of key new experiments to fill those gaps.
authors.affiliation: Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA. kevinh@niddk.nih.gov
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Hall
mesh_terms: D000818:Animals; D001823:Body Composition; D001835:Body Weight; D004032:Diet; D004734:Energy Metabolism; D006801:Humans; D008954:Models, Biological; D009765:Obesity; D010641:Phenotype