From my general knowledge (which I’ll admit is quite limited) I think it’s mainly to do with two things. Firstly, you’re trying out a lot of new things to replace the animal products. You only have to watch her vlogs to realise she’s kinda obsessed with chicken and relies on the fact that it’s low calorie and high protein at the same time. As someone who spends a lot of time in the gym, getting the same levels of protein is probably hard for her and she’s probably had to resort to extra tofu, nuts, quinoa etc, all of which are comparatively higher calorie.