This study was conducted to evaluate the effectiveness of short-term structured interventions on healthy lifestyle behaviors, dietary intake, anthropometric measures, blood pressure, fasting blood glucose, and serum lipid profile of middle-aged adults. Randomized controlled trial study. Overall, 300 individuals out of apparently healthy (non-patient) adults aged 40-60 yr living in Amirkola, Babol the north of Iran were enrolled in 2016-2017. The Persian translation of the Health Promoting Lifestyle Profile II (HPLP-II) and two days 24-h food recall questionnaires were used for data collection. Eligible participants were allocated randomly in three groups (high-intensive, low-intensive and the control). The follow-up examination has been conducted after 16 wk of intervention. The three study groups had no significant difference in age (P=0.888), sex (P=0.395), BMI (P=0.969), healthy lifestyle score (P=0.675) and total daily energy intake (P=0.612). After intervention, the mean scores of all the six subdomains of HPLP-II questionnaire had significant improvement (P<0.001). Mean weight loss was 1.5, 1.0 and 0.3 kg, in high-intensive, low-intensive and control groups, respectively. BMI although reduced, was still in the overweight range in two sexes. Mean of neck, arm, waist and buttock size, diastolic blood pressure, serum triglyceride, total cholesterol, and HDL levels have been changed to a better condition in comparison with the baseline values (P<0.001). Dietary intake had good changes in total daily energy (P<0.001), daily intake of carbohydrate, protein, and fat (P<0.001), and proportion of energy from carbohydrate (P=0.007) and fat (P=0.022) after the intervention. Our intervention program could have positive impact on healthy lifestyle behaviors, dietary intake and weight in addition to some other anthropometric variables and serum lipid profile of middle-aged adults.