Kratom abuse made my weight to drop quite significantly. It was during a period of stress though, and I didn't have the time to eat properly during the days. When I say properly, that doesn't mean I was eating fast/junk food, but stuff like carrots and fruits that I had in my shoulder bag. I was hiding my abuse from my surroundings, and I "blamed" my very obvious weight loss on the stress, the diet above and generally cutting out unhealthy food. My appetite was very suppressed by the kratom though, and that surely was the main reason for me losing all that weight.
After breaking the kratom habit I slowly began to gain some weight again. However, six months after quitting kratom, I began abusing tramadol, an episode lasting for about two years. Tramadol also suppressed my appetite and I was soon back to my "kratom weight". I ceased my use tramadol completely about ten days ago, and I estimate my appetite has tripled in the last few days. I already gained some weight surprisingly.
I should add that my diet is what many people would describe as “insanely healthy”, and my BMI is normal, but tipping towards the lower side of the scale. From an American perspective I guess I would be very thin, but coming from a lot less obese country, I’m considered quite slender but not unhealthy so.