yes guys its absolutely true doing only gym exercises without following diet is a waste of time and the thing is when your body is subjected to heavy exercises the muscles will get destroyed but they need some time to regain their originality but for that your body needs so much rest .
When you do exercises your muscle gets damaged and when you sleep it will get stronger so that it can bear the occurred damaged so by this way you can get shredded by following so mush of diet .
if you are so skinny you need to get a protein of at least 220gms per day so that your muscle can adsorb them to get stronger
for easier growth please take high proteins after the workout so that your body can adsorb more proteins and grow fasterthe guys who are fat need to control their diet by completely cutting the carbs and fat contents in their body so that they can become fit this can be accomplished by taking green vegetables and green salads. and oats fat less milk etc
guys muscle bodies are nothing but the best version you can take out from you and for building you should be very conscious about diet