He is trying to gain weight , how are you going to gain weight if your only taking in 2k calories a day on a fast metabolism ? I speak from ALL experience . Needs to take in ATLEAST 4k calories MIN plus 1-1.5g protein per 1lb of body weight. Also needs to take in complex carbs as well . I have friends that compete in competition and body build and study nutrition . How and why would you starve your body and muscles from not eating? To the OP , gain the weight first , gaining weight comes with some fat but you will have muscle under that plus you need a little, and when time comes you can cycle onto a nice shredder or cutdown program