A friend of mine who no longer takes drugs, he is in late 30's and he was telling me other day how about 10-15 years ago, he had to go the hospital for few days because he wasn't eating any solid foods for few weeks and his stomach got all knotted up and shrinked, he said he was in a lot of pain, and after the hospital scare, he quitted speed/meth ever since.
Take all the people's advice here, I seen some methheads getting their habits out of control and they get super paranoid. It's not a nice sight watching the people's lives going down the drain.
Quit meth, get some healthy meals and excercise instead.