The influence of individual choices and attitudes on adiposity.

Objective: To determine which dietary and lifestyle choices and which attitudes toward diet and health most contribute to adiposity and whether those factors differ by gender.

Methods: Multiple regression was used to estimate the effect of energy intake, energy expenditure, resources, demographics, and attitudes toward diet and health on self-reported body mass index (BMI) in a nationally representative sample of the US population.

Sample: This study used secondary data from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) and its telephone follow-up, the Diet and Health Knowledge Survey (DHKS). CSFII is a nationally representative survey of individuals which obtained 24 h recalls of all food intake on two nonconsecutive days. The DHKS data set obtained information on knowledge and attitudes toward dietary guidance and health from individuals 20 y of age and over, who participated in the CSFII. Our sample consisted of responses from 5512 individuals.

Results: We found that many of the variables previously found to or hypothesized to influence body weight do so. Our analysis shows that choices and attitudes do matter for adiposity. Moreover, the analysis shows that the choices males and females make often have quite different effects on BMI. For females all the variables we constructed to represent energy intake, energy expenditure, and financial and human resources are significant. Most of the variables that characterize attitudes toward diet and health are significant. For males, far fewer variables are significant. Our tests for gender-related differences show that whether or not males believe their weight is predetermined has no influence on BMI. In contrast, women who do not believe that their weight is predetermined have lower BMI values than those who believe weight is genetically determined.

Discussion: While our qualitative conclusion--choices and attitudes affect BMI--is unsurprising, the quantitative aspects are important. The analysis shows that factors affecting BMI differ systematically by gender. Understanding these systematic differences is critical to the design of information campaigns. Our analysis suggests that entirely different campaigns are necessary to communicate the importance of diet and lifestyle choices to men and to women.