Objective. To analyze the effect of Channa striata supplementation on body mass index among tuberculosis patients, in which their health status is also investigated. Methods. This study employed a true experiment. The study was designed randomized pretest-posttest with a control group, in which 200 respondents were enrolled. Body mass index (BMI), used as a nutritional status indicator, was measured every week for a month. Chi-square test was used to analyze the data with a significance level of 5% by STATA 13. Results. The mean BMI of all groups increases during the month, in which rapid alteration occurs in the treatment group. The mean BMI (kg/m2) in the treatment group at weeks 0–4 was reported to be 17.43, 17.65, 17.90, 18.04, and 18.22, respectively. Meanwhile, the mean BMI (kg/m2) at weeks 0–4 in the control group was reported to be 17.20, 17.36, 17.57, 17.71, and 17.96, respectively. Furthermore, the alteration from severe thinness to higher BMI level in the treatment group is the highest. Based on the statistical test, there were no differences in BMI between the treatment and control groups (p>0.05). However, the alteration of nutritional status in the treatment group is faster than that in the control group. In addition, there is no difference in their health status between the treatment and control groups (p>0.05), except vomiting (p<0.05). Conclusion. The BMI among tuberculosis patients with Channa striata supplementation is increasing faster than that in the control group within a month with a minimum potential negative effect.