I'm not able to regain a single gram of the 15 kg lost during last two years, diagnosed with Crohn's but it is has been treated and im still on meds?

Work with a . clinical nutritionist who understands your condition, and can recommend a good diet for your Chron's disease that's anti-inflammatory. Also get a Food Antigen Complement testing done to avoid eating foods that you're allergic to that's inflaming your gut lining. Since cytokines are active in your disease, stress management is key to your healing too.