Why might someone be gaining muscle but not losing weight if they're eating right and exercising?

The biggest issue is the definition of eating, and people may not be doing it correctly. This could be why someone is gaining muscle but not losing weight. There are a lot of variables involved, so there is not one simple answer.
 
Transcript: "So there are there are a lot of variables associated with individuals nutrition and exercising. So why someone might be gaining muscle but not be losing weight. Can be directly related to what the person is really doing the bigger issue. Unfortunately, is a lot of times think they're people think they're doing one thing correctly when in actuality, they're not necessarily doing it correctly. The biggest problem is the definition of eating, right? And you can ask five different people and you'll get five different answers on what it means to eat, right? Everybody has their own Theory, their own belief, as I have my own and I don't often agree with nutritionist or dietitian and as far as exercising, what type of exercises version do, and if they're doing primarily resistance training than sure, they're going to gain muscle but of course, if the Eating right. Hang upon what it is that they're eating? They may not be actually losing body fat. So that's there's a lot of variables involved and to give a very specific answer as to why a person is doing one thing versus the other. It's not in such a simple answer."