Objective: To investigate the longitudinal relationship between body mass ind ex (BMI), a major vascular risk fac tor, and cerebral atrophy, a marker of neurodegeneration, in a population-b ased sample of middle-aged women. Methods: A representative sample of 290 wome n born in 1908, 1914, 1918, and 1922 was examined in 1968 to 1969, 1974 to 1975, 1980 to 1981, and 1992 to 1993 as part of the Population Study of Women in G teborg, Sweden. At each examination, women completed a survey on a variety of he alth and lifestyle factors and underwent anthropometric, clinical, and neuropsyc hiatric assessments and blood collection. Atrophy of the temporal, frontal, occi pital, and parietal lobes was measured on CT in 1992 when participants were age 70 to 84. Univariate and multivariate regression analyses were used to assess th e relationship between BMI and brain measures. Results: Women with atrophy of th e temporal lobe were, on average, 1.1 to 1.5 kg/m2 higher in BMI at all examinat ions than women without temporal atrophy (p < 0.05). Multivariate analyses showe d that age and BMI were the only significant predictors of temporal atrophy. Ris k of temporal atrophy increased 13 to 16% per 1.0-kg/m2 increase in BMI (p < 0.05). There were no associations between BMI and atrophy measured at three ot her brain locations. Conclusion: Overweight and obesity throughout adult life ma y contribute to the development of temporal atrophy in women. Objective: To investigate the longitudinal relationship between body mass ind ex (BMI), a major vascular risk fac tor, and cerebral atrophy, a marker of neurodegeneration, in a population-b ased sample of middle-aged women. Methods: A representative sample of 290 wome n born in 1908, 1914, 1918, and 1922 was examined in 1968 to 1969, 1974 to 1975, 1980 to 1981, and 1992 to 1993 as part of the Population Study of Women in G teborg, Sweden. At each examination, women completed a survey on a variety of he alth and lifestyle factors and underwent anthropometric, clinical, and neuropsyc hiatric assessments and blood collection. Atrophy of the temporal, frontal, occi pital, and parietal lobes was measured on CT in 1992 when participants were age 70 to 84. Univariate and multivariate regression analyzes were used to assess th e relationship between BMI and brain measures. Results: Women with atrophy of th e temporal lobe were, on average, 1.1 to 1.5 kg / m 2 higher in BMI at all examinat ions than women without temporal atrophy (p <0.05). Multivariate analyzes showe d that age and BMI were the only significant predictors of temporal atrophy. Ris k of temporal atrophy increased 13 to 16% per 1.0-kg / m2 increase in BMI (p < 0.05). There were no associations between BMI and atrophy measured at three ot her brain locations. Conclusion: Overweight and obesity throughout adult life ma y contribute to the development of temporal atrophy in women.