I started going to the gym what's the best diet for losing weight and gain muscle i don't want very hard diet because i have lots of study and exams

Eat healthy!: In general, there's no one guaranteed diet or way to eat. Taking the long view, DASH, Mediterranean & vegetarian diets have all been demonstrated to produce positive health outcomes years down the road. But if you're set on putting on muscle now, plan on consuming upwards of 0.7-1gm/d protein for each pound you weigh: http://goo.gl/srbiHE & http://goo.gl/CdUyxx. Some will advocate 2gm/d.