Obesity and Nutritional Knowledge
- Presenter:
Mon June 5, 2006 9:30-10:45 Room Alumni Lounge
Rationale: Currently, obesity presents one of the biggest public health problems. From a public policy perceptive, it is important to know whether propagation of nutritional knowledge could be used as an effective public policy tool in reducing the prevalence of obesity.
Objective: The objective of this paper is to examine the relationship between nutritional knowledge and obesity.
Methodology: This study uses the 1999 wave of the Panel Study of Income Dynamics (PSID). PSID is a longitudinal study of a representative sample of U.S. individuals and the family units in which they reside. The 1999 wave of PSID used in this study contains questions on height, weight, nutritional knowledge and attitude toward importance of balanced diet of the respondents. The econometric technique used is ordered probit with known cut points, i.e. interval regression model.
Results: The main result is that there are two distinct patterns in the relationship between nutritional knowledge obesity. First, for individuals attaching greater importance to a balanced diet, greater nutritional knowledge corresponds to a lower probability of being obese. This pattern is consistent with the notion of preventive nutritional knowledge: persons who are aware of the connection between poor nutrition and certain health conditions have higher expected costs associated with obesity and are more likely to follow a balanced diet and avoid obesity. Second, for individuals who attach low importance to balanced diet, greater nutritional knowledge corresponds to greater probability of being obese. This pattern is consistent with the notion of reactive nutritional knowledge: obese persons, especially those with obesity-associated health conditions are more likely to be aware of health problems caused by dietary imbalances and obesity and would be more likely to possess greater nutritional knowledge due to his/her condition. Empirical analysis reveals that consistent with the pattern of preventive nutritional knowledge the negative effect of nutritional knowledge on the probability of being obese or overweight for women without obesity-related conditions is double that for women with such conditions. Likewise, consistent with the pattern of reactive nutritional knowledge the positive relationship between nutritional knowledge and the probability of being obese without obesity-related conditions is half that for men with such conditions.
Conclusion: The analysis shows that there are two distinctive patterns in the relationship between nutritional knowledge obesity. Nutritional knowledge could be preventive to obesity, in which case greater nutritional knowledge leads to lower probability of being obese. Nutritional knowledge could also be reactive to obesity, in which case obesity leads greater nutritional knowledge. Ignoring the reactive effect of nutritional knowledge, while estimating the size of its preventive effect on obesity, may lead to biased and insignificant estimates.
