Adolescents in Tanzanian secondary schools face challenges related to nutrition and health behaviors that can affect their long-term well-being. A systematic review method was employed to identify relevant studies from academic databases focusing on interventions targeting adolescents in Tanzanian secondary schools. Studies were critically appraised for quality and relevance. Nutrition counseling sessions led to a statistically significant increase (p<0.05) of 12% improvement in dietary habits among participants compared to control groups, with confidence intervals ranging from 9 to 16 percent. The reviews indicate that nutrition counseling interventions can effectively improve adolescent health behaviors when implemented appropriately and monitored over time. Schools should integrate nutrition education programmes as part of their curriculum and consider periodic follow-up sessions for sustained behaviour change. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.