Catching Elephant is a theme by Andy Taylor
For as far as I understand it depends on what you eat. If you want to work on actually building more muscle tissue, you will probably need protein above all else. On top of that it depends on your metabolic system how easily you gain muscle and/or lose weight, it can vary wildly from person to person.
In general though, cardio is never a bad idea for losing weight, and if you’re on a weight loss plan just cut down on the junk food, the simple carbs, the saturated fatty acids, etc. While if you’re trying to bulk up, up your protein intake.
In both cases, drink plenty of water and eat healthy, can’t go wrong there. ;)