Disparities in Prevalence

Between the second and third National Health and Nutrition Examination Surveys (NHANES II and III), the prevalence of overweight and obesity (BMI ≥ 25 for adults and ≥ the 95th percentile for age and gender in children) increased in both genders, across all races and ethnicities, and across all age groups.^15,30 Disparities in overweight and obesity prevalence exist in many segments of the population based on race and ethnicity, gender, age, and socioeconomic status. For example, overweight and obesity are particularly common among minority groups and those with a lower family income.

Race and Ethnicity, Gender, and Age

In general, the prevalence of overweight and obesity is higher in women who are members of racial and ethnic minority populations than in non-Hispanic white women. Among men, Mexican Americans have a higher prevalence of overweight and obesity than non-Hispanic whites or non-Hispanic blacks. For non-Hispanic men, the prevalence of overweight and obesity among whites is slightly greater than among blacks.³⁰

Within racial groups, gender disparities exist, although not always in the same direction. Based on NHANES III (1988–1994),³⁰ the proportion of non-Hispanic black women who were overweight or obese (BMI ≥ 25; 69 percent) was higher than the proportion of non-Hispanic black men (58 percent) (figure 6). For non-Hispanic whites, on the other hand, the proportion of men who were overweight or obese (BMI ≥ 25; 62 percent) exceeded the proportion of women (47 percent). However, when looking at obesity alone (BMI ≥ 30), the prevalence was slightly higher in non-Hispanic white women compared to non-Hispanic white men (23 percent and 21 percent, respectively).³⁰ The prevalence of overweight or obesity (BMI ≥ 25) was about the same in Mexican American men and women (69 percent and 70 percent, respectively).³⁰ Although smaller surveys indicate a higher prevalence of overweight and obesity in American Indians, Alaska Natives, and Pacific Islander Americans and a lower prevalence in Asian Americans compared to the general population, the number surveyed in NHANES III was too small to reliably report prevalence comparisons of overweight and obesity for these populations.³⁴

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Racial and ethnic disparities in overweight may also occur in children and adolescents. Data for youth from NHANES III showed a similar pattern to that seen among adults. Mexican American boys tended to have a higher prevalence of overweight than non- Hispanic black and non-Hispanic white boys. Non-Hispanic black girls tended to have a higher prevalence of overweight compared to non-Hispanic white and Mexican American girls.¹⁵ The National Heart, Lung, and Blood Institute Growth and Health Study on overweight in children found a higher mean BMI for black girls aged 9 and 10 years, compared to white girls of the same ages.³⁵ This racial difference in BMI widened and was even greater at age 19.³⁶

In addition to racial and ethnic and gender disparities, the prevalence of overweight and obesity also varies by age. Among both men and women, the prevalence of overweight and obesity increases with advancing age until the sixth decade, after which it starts to decline.³⁰

Socioeconomic Status

Disparities in the prevalence of overweight and obesity also exist based on socioeconomic status. For all racial and ethnic groups combined, women of lower socioeconomic status (income ≤ 130 percent of poverty threshold) are approximately 50 percent more likely to be obese than those with higher socioeconomic status (income > 130 percent of poverty threshold). Men are about equally likely to be obese whether they are in a low or high socioeconomic group.³⁷

Among children, the relationship between socioeconomic status and overweight in girls is weaker than it is in women; that is, girls from lower income families have not consistently been found to be overweight compared to girls from higher income families. Among Mexican American and non-Hispanic black children and adolescents, family income does not reliably predict overweight prevalence. However, non-Hispanic white adolescents from lower income families experience a greater prevalence of overweight than those from higher income families.¹⁵

Last revised: January 11, 2007