The Women's Healthy Lifestyle Project is a 5-year randomized clinical testing whether a behavioral intervention aimed at lifestyle changes in diet and physical activity can prevent the rise in weight and low-density lipoprotein cholesterol (LDL-c) observed during menopause. Cardiovascular risk factor and behavioral data from 489 participants (intervention group n = 236; control group n = 253) who attended baseline, 6-month, and 18-month clinical assessments were analyzed to determine how well initial improvements achieved at 6 months were maintained over the subsequent year of follow-up. Results indicated that the treatment effect persisted at 18 months for weight, body mass index, total cholesterol, LDL-c, systolic blood pressure (SBP), and glucose levels. Intervention participants maintained improvements in physical activity, caloric intake, dietary cholesterol, SBP, and glucose levels between 6 and 18 months, although weight, total cholesterol, and LDL-c began to rise during this period. Eighty percent of intervention participants compared to 45% of controls were at or under baseline weight at 18 months, suggesting that promoting modest weight loss may be an effective approach to preventing weight gain in these women.