Lower socioeconomic position (SEP) is associated with higher
adult BMI, suggests previous studies. But, whether those associations have changed over the past
decades was unclear.
Both childhood and adult socioeconomic position continue to be associated with adult body mass index (BMI) in Britain despite policies designed to reduce BMI inequalities, suggested to a study published in PLOS Medicine by David Bann, from the UCL Institute of Education, UK, and colleagues.
In the new study, researchers examined data on 22,810 people enrolled in three British birth cohort studies: the 1946 MRC National Survey of Health and Development, including people aged 20 to 64; the 1958 National Child Development Study, including people aged 23 to 50; and the 1970 British Birth Cohort Study, including people aged 26 to 42. Data were collected on each person's SEP as a child (based on father's occupation) and adult (based on own occupation), and on their BMI throughout adulthood.
For example, among those born in 1946, 42-43 year-old women in the lowest SEP group (unskilled occupations) had a BMI 2.0 kg/m2 higher than those in the highest SEP group (professional occupations); among those born in 1970 that difference had grown to 3.9 kg/m2.
"The persistence of inequalities in BMI throughout adulthood across different generations suggests that new and/or improved strategies are required to reduce them," the authors say. "Given our findings of progressively widening BMI inequalities across adulthood, and the fact that BMI tends to track across life, interventions may be most effective when initiated as early in life as possible."