Gaining muscle mass without diet is tough, perhaps impossible
I'm using my friend as a case study here. We'll call him Richard because that is his name. Rich will ask me about muscle mass because while we do not work out together because I hate working out with other people, he does ask me questions because I have muscle mass and he is kind of wirey. He is thin and tall, so this is two good things working out for him but he plays football a couple times a week, goes to the gym 3 times a week and goes on runs as well. However, he doesn't gain any muscle mass and I have tried over and over to tell him that if he ever wants to accomplish this, he is going to have to alter his diet.
Because I know that he works out hard, perhaps even harder than I do, I have asked him multiple times what his diet consists of. He has a typical American diet of mostly carbohydrate stuff like pasta, sandwiches, pizza, and the like. He doesn't necessarily eat an unhealthy diet, but there is one thing that is definitely missing from his program: Protein.
You can ask anyone in the fitness game that is into bodybuilding or most combat sports and everyone will tell you the same thing: You have to get a certain amount of protein in your diet if you ever hope to gain muscle mass.
Will you get stronger without the protein? yeah, of course. However, if your objective is to get bigger you have to give your body the fuel that it needs in order to do that. You see, when you do exercise and end up a bit sore afterwards, especially during a weight-lifting session, this is because the muscle tissue in your body has been damaged a bit and this is normal. Our bodies have an incredible ability to self-heal and if you continually "damage" your muscle fibers your body will automatically attempt to make those muscle fibers stronger as a method of self-defense. When someone gets really muscular, it is because of the fact that they have kind of tricked their body into over-compensating for presumed future "damage."
These don't sound like professional terms but if you care to look into the scientific side of things there are tons of articles that show how protein is an absolutely essential part of building mass and especially muscle-mass. this is a good one that is written by a professional nutritionist and is peer-reviewed by a Chief Medical Officer who is an actual doctor. It's not just some mumbo jumbo that people like me who like to go to the gym to get bigger made up so that we can sell whey protein powder.
As I have mentioned many times before, whey protein is one of the ONLY supplements that is advertised to athletes and bodybuilders that I actually believe in. This of course is only necessary if you are having difficulty meeting your protein needs from normal food. Obviously, regular food is always the best choice but when you consider that you need around 1.2-2 grams of protein per day per kg of existing body-weight, it can be a bit difficult to manage to get that much protein in your diet without meal planning and purchasing a lot of meats.
When I spoke to Rich about his diet he told me that he has just been eating more calories and honestly, this is the wrong approach. If you are attempting to build muscle mass, it isn't really the amount of calories that are important, it is the KIND of calories you are taking in. If Rich is eating 4000 calories of pizza and pasta every day but only getting a tiny bit of protein, he simply isn't going to be capable of building muscle mass. This is true for literally everyone else as well.
I have recommended that Rich start drinking 2 protein shakes a day because this will get him up to 55 grams of protein just on their own. They also contain very little in the way of calories and this is by design. With Rich's current approach of working out with a ton of calories he stands a much better chance of getting fat than he does of gaining muscle. He is in his late 30's and still has an amazing metabolism, so the "turning of the metabolism corner" hasn't happened for him yet. When he gets to that point, if he doesn't adjust his diet, he is going to be in big trouble and probably end up depressed because of it.
They always say that you "can't out exercise a bad diet" and almost any nutritionist or personal trainer will tell you that changing your body is 80% diet and only 20% exercise. Many people focus entirely too much on the 20% when it is the other thing that they should be looking at.
Rich has recently taken my advice and gotten a hold of some whey protein. I hope he sticks with it because it still takes some time before you are going to notice anything that you can really see in the mirror. It really does work and if you can afford it, it is perfectly ok to ONLY get your protein from protein shakes. It might be a boring way of getting it but it does the trick!
My information doesn't come from going to school, it has come from living it. I went from skinny athlete in my 20's, to a fat ass in my 30's, and to the strongest and most muscular that I have ever been in my life in my 40's. If I can do it, I think almost anyone else can as well