The Centers for Disease Control conducted a review of the literature on obesity in children over a 40-50 year period. In 1960, the percentage of adults with obesity was 13%. By 2010 it had reached 36%. When looking at children, obesity was sated to be 5% in the early 1970s and then reached 17% in 2010. Rates of obesity since 2020 are even higher and will be discussed in other reports. At least for this period, the rates of child obesity have tripled. Other studies in this section will show that a range of EDCs (Endocrine Disrupting Chemicals) can alter hormone signaling and increase the growth of fat cells (known as adipogenesis).
RESULTS
Between 1999–2002 and 2007–2010, the age-adjusted prevalence of obesity among adults aged ≥18 years increased from 26.5% to 33.0% among men and from 32.4% to 34.9% among women (Table 1). Controlling for age and race/ethnicity in regression models indicated that the increase in the prevalence of obesity over the study period was statistically significant among men but not among women.
The prevalence of obesity differed substantially across categories of various demographic characteristics (Table 1). Among men, there was little difference in the prevalence of obesity by race/ethnicity, but among women, the overall (1999–2010) prevalence among non-Hispanic blacks (51%) was 10 percentage points higher than that among Mexican-Americans and 20 percentage points higher than that among non-Hispanic white women.
Inverse associations were identified between the prevalence of obesity and educational attainment that were statistically significant among both men and women; differences were much greater among women (Table 1). These associations appeared to be nonlinear. For example, among men, the prevalence was lowest (25%) among college graduates but highest (35%) among those who had completed some college. Among women, the overall prevalence of obesity among those who had completed college was 13–16 percentage points lower than in other groups, but there was little difference in obesity prevalence between those who had not finished high school and those who had completed some college. The analysis of disability status of adults aged ≥60 years indicated that the overall prevalence of obesity among those who reported having difficulties with four or more activities was substantially higher than obesity prevalence among those without a disability (men: 16 percentage points higher; women: 27 percentage points higher).
In contrast to these differences, which were larger among women, the association of obesity with country of birth and language spoken at home was stronger among men (Table 1). Mexican-American men who were born in the United States had 13 percentage points higher overall prevalence of obesity than men born in Mexico (39% versus. 26%), but the equivalent difference among Mexican-American women was only 3 percentage points. Similarly, Mexican-American men who spoke mostly English at home had a 12 percentage points higher overall prevalence of obesity compared with those who spoke mostly Spanish at home (38% versus 26%), while there was no significant difference among Mexican-American women. As assessed by an interaction term (each characteristic x study period) in sex-specific regression models, there was no indication that disparities in obesity prevalence varied across the 12-year study period among either men or women.
Between 1999–2002 and 2007–2010, the prevalence of obesity among children and adolescents aged 2–17 years increased from 15.4% to 18.6% among boys and from 13.8% to 15.1% among girls (Table 2). After adjustment for age and race/ethnicity in regression models, the increase over the six 2-year study cycles was statistically significant among boys but not among girls.
Differences in the prevalence of obesity among children and adolescents over the 12-year study period across categories of the various characteristics were somewhat similar to those among adults (Tables 1 and 2). Substantial differences existed in the prevalence of obesity by race/ethnicity; among boys, prevalence was highest among Mexican-Americans (24%), whereas among girls, prevalence was highest among non-Hispanic blacks (22%). Educational attainment of the adult head of household was associated inversely with obesity among both boys and girls. Overall, the prevalence of obesity among children and adolescents whose adult head of household had completed college was approximately half that of prevalence among children whose adult head of household did not complete high school. In contrast to the differences among adults, the prevalence of obesity among Mexican-American children did not differ significantly according to either country of birth or language spoken at home.