Body habitus changes among adult males from the normative aging study: relations to aging, smoking history and alcohol intake. Obes Res. 1995;3:435–446. The Normative Aging Study (NAS) recruited 2280 Boston area healthy males aged 21 to 80 in 1961 through 1970. Clinical exams have continued at 3‐ to 5‐year intervals. Obesity was not an exclusion criterion. Stability in weight and body habitus among 867 adult participants in the NAS was evaluated at 5‐and 15‐year follow‐ups. At study entry, age was linearly related to central adiposity [abdominal circumference (AC) and ratio of AC/Hip Breadth (HB)] throughout the entire age range (30 to 78 years) and linearly and quadratically related to weight (WT) and Body Mass Index (BMI) (kg/m²) with maximal values at age 50. Over 15 years, changes in adiposity were strongly related to age; the greatest increases were among those initially 30 to 44 years of age with decrements in several adiposity measures (BMI, AC) only among the oldest subjects (60+ at entry); significant quadratic effects of age for BMI (p<. 001), WT (p<. 02) and AC (p<. 01). There were major secular differences; men born later were heavier and fatter at the same ages as men born earlier. Men who gained (>1 BMI) were younger while men who lost (>1 BMI) had greater initial central adiposity than others. Smoking cessation was independently associated with increments in both central and peripheral adiposity. Moderate alcohol intake was associated with lower gains in AC/HB ratios at 15 years compared with little or high consumption. In general, aging was associated with trends towards central adiposity which tended to plateau or decrease at the oldest ages.