title: The growth of obesity and technological change.
abstract: This paper presents a dynamic theory of body weight and develops its implications. We argue that technological change has induced weight growth by making home- and market-production more sedentary and by lowering food prices through agricultural innovation. In addition, we illustrate that, while exercise and food intake are complements, reductions in exercise will always raise optimal body weight, as will increases in food intake. We also characterize how body weight varies with income, both within a country, and across countries. Within a country, income may have an inverted U-shaped relationship with body weight, due to the offsetting effects of the demand for food, and the demand for an ideal body weight. This can have important implications for the body weight impacts of public transfer programs. Across countries, however, mean weight is likely to be higher in richer countries. Finally, we present descriptive empirical evidence that illustrates the inverted U-shaped relationship between body weight and income in US males, and suggests the importance of secular trends in weight gain, which are consistent with the impacts of broad-based technological changes.
authors.affiliation: Schaeffer Center for Health Policy and Economicsa, and School of Policy, Planning, and Development, University of Southern California, 650 Childs Way, Los Angeles, CA 90089-0626, United States. Darius.Lakdawalla@usc.edu
authors.forename: Darius
authors.initials: D
authors.lastname: Lakdawalla
authors.forename: Tomas
authors.initials: T
authors.lastname: Philipson
mesh_terms: D000367:Age Factors; D001837:Body Weights and Measures; D003431:Cross-Cultural Comparison; D004032:Diet; D015444:Exercise; D005523:Food Supply / Q000191:economics*; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D009765:Obesity / Q000453:epidemiology*; D044469:Racial Groups; D012737:Sex Factors; D013672:Technology; D013997:Time Factors