Posted on August 6, 2012

In U.S., Being Middle-Aged Most Linked to Having Higher BMI

Frank Newport et al., Gallup, August 6, 2012

Being middle-aged or black is more closely linked to being overweight — defined as having a high Body Mass Index — than any of 25 other factors, including exercise and healthy eating, examined in a Gallup analysis of the correlates of weight in America today. The analysis of interviews with more than 850,000 Americans also finds that being a man, having a lower level of education, not smoking, and not exercising are also strongly related to being overweight. Conversely, being very young or very old, Asian, a woman, having a high education level, smoking, and exercising three or more days per week are linked to having a low BMI.

{snip} Gallup calculates respondents’ BMI using the standard formula based on their self-reported height and weight. In these data, the average BMI for U.S. adults was 27.0. {snip}

Average BMI Increases as Americans Enter Middle Age

Americans’ BMIs are lowest when they are quite young — an average of 24.9 among those aged 18 to 24 — but begin to rise as Americans age, peaking in the 55 to 59 age group at an average of 28.5. BMI begins to fall thereafter, particularly when Americans reach the age of 80. {snip}

Blacks and Asians at High and Low End of BMI Spectrum

The majority of Americans are non-Hispanic whites, so it is to be expected to find that whites’ average BMI (26.8) is close to the national average. Hispanics’ average BMI is also close to the national average. On the other hand, the two racial groups that stand out are blacks and Asians.

Blacks have the highest average BMI score (28.2) of any major race or ethnic group, while Asians have the lowest — 25.1. Given that these estimates are based on an analysis that controls for a list of demographic factors that are correlated with race and with weight, the results suggest that something about either the genetics or social and cultural environments of these racial groups may be responsible for their relative weight status.