The first chapter of this dissertation tests for addiction to food. This is the first empirical study using nationally representative data to do so. Data show that many common foods are addictive, suggesting that prices play a larger role in food consumption than previously thought. The finding of significant addiction also suggests that targeted food taxes may provide effective instruments for reducing the prevalence of overweight and obesity. The second chapter of this dissertation investigates the determinants of childhood obesity. This research improves upon previous economic research on the topic by incorporating controls for biological relationships of mothers and fathers and examining the entire child weight distribution using quantile regression. I find evidence of genetic weight transmission though the behavioral influence of mothers appears to be dominant. Furthermore, I find that the commonly cited influences on childhood weight do little to explain the most extreme weights. The third chapter of this dissertation studies the contract choice effect. Though frequently discussed, the impact of changes in insurance contract on utilization in response to a change in the expected cost of care has not been explicitly studied in an empirical setting. The analysis identifies a significantly negative contract choice effect, implying that individuals choose better insurance plans in response to increases in the expected cost of care. / text