You know the circus performer who spins the plates in the air you know, and he'll spin six or seven plates in the air? Acting sometimes is kind of that guy spinning all those plates in the air but in your head and in your body. ↗
Sometimes your body language is enough for an actor to know that you're not happy. And you don't really need to say it out loud if you deal with actors you know very well. And I don't think you really need to be explicit. ↗
While weight loss is important, what's more important is the quality of food you put in your body - food is information that quickly changes your metabolism and genes. ↗