Study links obesity across childhood with lower future education, employment and earnings – with differences in men and women

New research to be presented at this year’s European Congress on Obesity (ECO 2026, Istanbul, Turkey, 12-15 May) shows that living with obesity across childhood is associated with lower future levels of education, employment and earnings. The study is by Dr Lise Bjerregaard, Dr Elisabeth Andersen and research group leader Dr Jennifer Lyn Baker of the Center for Clinical Research and Prevention, Copenhagen University Hospital – Bispebjerg and Frederiksberg, Copenhagen, Denmark.

Evidence from longitudinal studies suggests that obesity in adolescence, but not earlier in childhood, is associated with school performance. However, studies examining obesity in childhood in relation to post-secondary educational attainment, income or labour force participation are limited and have yielded inconsistent results (see notes to editors for some published studies).

In this new study, the authors examined whether body mass index (BMI) development across childhood is associated with educational attainment, income and labour force participation in adulthood and if sex and parental education modified these associations.

The authors used data from 134,555 individuals (48% women) born 1951-1991 who were in the Copenhagen School Health Records Register. Weights and heights were measured regularly at school health examinations at ages 6-15 years. From this, the authors divided individuals into five childhood BMI trajectory groups: below-average, average, above-average, overweight, obesity. Socioeconomic information came from national registers (until 2022). Associations were estimated by sex and parental education (low/medium/high) using regression and advanced modeling methods.

Most boys and girls followed the average BMI trajectory and the fewest belonged to the obesity trajectory. Compared to girls with an average BMI pattern growing up, girls who had obesity during childhood tended to complete fewer years of education. On average, they had 3 fewer months of schooling if their parents had low education levels, 6 fewer months if their parents had medium education, and 13 fewer months if their parents had high education. For men the associations were similar (3, 6 and 12 fewer months of education, respectively). One potential explanation may be that the causes and social consequences of obesity differ by socioeconomic context such that obesity is more negatively perceived in certain social environments – the more educated the parents, the more negative the impact on the child’s education if they are living with obesity.

Females with the obesity BMI trajectory had annual incomes that were lower by -$360 and -$5720 among females with parents with low and high levels of education, respectively, compared with those with the average BMI trajectory. In males the corresponding estimates were -$4230 and -$9580.

In females, the obesity childhood BMI trajectory was associated with 34%, 71% and 90% excess risk of being outside the labour force at age 50 years across levels of parental education compared with the average BMI trajectory – In males, there was no statistically significant associations with this outcome.

Lead author Dr Bjerregaard says: “Obesity in childhood was associated with substantial long-term socioeconomic disadvantage. Among females and males, these effects of obesity across childhood were seen most in those with highly educated parents, as they had a markedly shorter education and lower adult income.”

Senior author Dr. Baker says: “Only among females with obesity in childhood was there a higher risk of being out of the labour force by midlife. In males, obesity in childhood did not seem to affect their chances of being in work at age 50 years. However, the impact on future pay was much higher in men who had lived with obesity as a child than women.”

She adds: “These findings suggest that the long-term consequences of obesity in childhood are shaped by parental educational context, suggesting there are additional social or structural mechanisms beyond obesity itself.”