I am losing weight and don't know why and don't need to be. i work as a cook and i smoke cigarettes and weed and drink occasionally ?

Need MD evaluation: You need to see your physician for a thorough evaluation. There are many causes; some are related to the foodstuffs that you handle, some can be related to infections caught at work, but many have nothing to do with your work. You need your physician to sort out all of these possibilities and give you the cause and the appropriate treatment