**Background:** Unhealthy food consumption and physical inactivity during adolescence are critical contributors to the early development of non-communicable diseases (NCDs), including obesity, diabetes, hypertension, and cardiovascular diseases. Despite known benefits of proper diet and exercise—such as bone development, physical fitness, reduced stress, and improved academic performance—more than half of Indian adolescents consume unhealthy foods and lack sufficient physical activity. Previous health promotion interventions have been only marginally effective due to a lack of context-specific strategies. This study aimed to capture the reasons for unhealthy food consumption and physical inactivity among school-going adolescents and to identify and prioritize feasible action points for health promotion.
**Methods:** A school-based sequential mixed-methods study (QUAN → QUAL → QUAL) was conducted over six months (January 2021 to June 2021) in two private higher secondary schools in urban Puducherry, South India. In Phase I, a quantitative survey was administered to 405 students (9th–12th standards) selected via simple random sampling from a sampling frame of 1,200 students. Food consumption was assessed using the youth/adolescent food frequency questionnaire (Harvard University), and physical activity was estimated using the 7-day physical activity recall questionnaire (Stanford). Unhealthy food consumption was defined as consuming junk foods more than once a week, skipping meals, or avoiding fruits and vegetables. Adequate physical activity was defined per WHO recommendations (at least 60 minutes/day of moderate-to-vigorous intensity aerobic activity). Data were analyzed in Epi_Info 7.1.5.0. In Phase II, two focus group discussions (FGDs) were conducted with 20 purposively selected participants (principals, teachers, parents, and healthcare professionals) to explore solutions. Thematic content analysis was performed using Atlas.ti.9 software following a deductive approach. In Phase III, 60 teachers ranked 20 feasible action points (10 for diet, 10 for physical activity) from highest to lowest priority. Mean ranks and Kendall's coefficient of concordance (W) were calculated using SPSS 24.
**Key Results:** The mean age of students was 16 ± 4.5 years; 52.1% were females, 95.8% resided in urban areas, 75.3% lived in nuclear families, 93.3% had a head of family with formal education, 91.9% were above the poverty line, and 70.4% had both parents working. Overall, 284 students (70.1%) consumed unhealthy food and 247 (61.0%) were physically inactive. Among those with unhealthy food consumption, 59.9% were males and 40.1% were females. Among physically inactive students, 65.2% were females and 34.8% were males. The leading self-reported reasons for unhealthy eating were: taste of fast/junk foods (78.9%), increased online food delivery (75.7%), attractive advertisements (74.3%), negative peer influences (69.0%), and easy ready-made food preparations (58.4%). The prime reasons for physical inactivity were: increased study load and extra classes (81.8%), high-density traffic (74.9%), lack of recreational/sports facilities (71.7%), increased social media usage (70.0%), and reduced physical education training periods for higher classes (67.6%). From the FGDs, solutions were organized under three themes: actions at the family, school, and community levels. The top five prioritized action points to promote healthy diet (by mean rank) were: inspection and monitoring of food outlets (mean rank 2.9), ban on junk food advertisements (3.2), maintaining kitchen gardens at home (5.7), nutrition-related health education sessions in schools (6.6), and trying new dishes with organic foods (6.9). For physical activity, the top five were: reduce study load and extra classes (3.4), friendly environment for children outside home and school (4.5), increase sports/recreational facilities (4.9), monitor and limit children's social media usage (5.0), and construct separate paths for walking and cycling (6.2). Kendall's W was 0.4 for healthy diet action points and 0.5 for physical activity action points, indicating moderate agreement among raters.
**Clinical Implications:** This study provides evidence that unhealthy food consumption and physical inactivity are highly prevalent among urban school-going adolescents in South India, with distinct gender patterns—males more prone to unhealthy diets and females to physical inactivity. The identified reasons (taste, online food delivery, advertisements, study load, traffic, lack of facilities) highlight the need for multi-level interventions targeting family, school, and community environments. The prioritized action points offer a feasible, context-specific framework for developing behavior change communication strategies in resource-poor settings. Implementing these strategies—such as food outlet regulation, banning junk food ads, reducing academic burden, and improving recreational infrastructure—could serve as a cost-effective primordial prevention approach for NCDs. General primary care providers and family physicians can leverage these findings to enhance health promotion activities for adolescents.