Firstly, Durianrider has zero credibility. Just watch one of his youtube rambling rants. The brain is made up mostly of fats, and it's now proven that dietary fats are necessary to prevent Alzheimer's Disease. Secondly, I am a CrossFitter and the entire diet is clean. So don't throw that random crap about a very few CrossFitters. Let's look at the majority.
Do competitive sports have problems with performance enhancing drugs? Yes, but MOST CrossFitters are not taking steroids. My point is the diet. It is norefined carb, Sugar free, gluten free, dairy free, no processed foods. Does everyone follow it? Of course not. We hold to the 80% rule, which is to try to follow it 80% of the time. My point is also that these people are not malnourished for being low carb.