I'm already maintaining a low BMI/BF% and from reading Stephan's latest posts on carbohydrates, I've decided a low-fat diet might not be so bad, and to try it. I have no issues with carbohydrates e.g. wheat and not diabetic.
I want to cut down on protein costs, so it seems that if I buy a low-fat protein powder in bulk, e.g. Isopure, then I could save on the cost per gram protein. I'm not allergic to dairy, and whey protein seems to have some beneficial qualities.
What might be the long-term consequences of replacing the usual protein with whey/casein protein powder instead? How would you know if you're deficient in something, what health markers or lab results would you look at? Do you think a protein powder-based diet is unsustainable?
I've maintained my diet and marginally reduced my weight since I asked this. It was a nice experiment. Works for me but not everyone. Interesting nobody could answer my second question.