Birth weight, climate at birth and the risk of obesity in adult life

OBJECTIVE: To determine whether obesity in adults is related to seasonal or climatic conditions around the time of birth. SUBJECTS: 1750 men and women born in Hertfordshire between 1920 and 1930, MEASUREMENTS: Height and weight measured in the home by trained fieldworker s. RESULTS: Body mass index (BMI) rose with increasing birth weight in men and women, In men, BMI and the prevalence of obesity (BMI greater than or equa l to 30 kg/m(2)) varied as a function of month of birth and was greater amo ng those born in January-June than among those born in July-December. The r elationship between birth weight and adult obesity was also stronger in tho se born in the first 6 months of the year or following cold winters than in those born in the last 6 months of the year or following mild winters. CONCLUSIONS: These findings suggest that adult obesity is linked both to hi gh birth weight and to early cold exposure, Consequently, exposures in earl y life may contribute to individual variation in susceptibility to obesity in adults.