"Bulletproof Coffee"(TM) is snake oil stuff. It's based on the assumption that all other coffee on the market has mycotoxins, yet literally none of the brands in first world countries have them anyway. This was confirmed by tests.
He started off by selling high-fat coffee creamer and sugar-free hot chocolate, which are reasonable. It's only later he's gone on to try to convince everyone coffee and wine are full of secret mold toxins.
Maybe your weight loss rate accelerated because you started watching what you eat more carefully, knowing that you want to provide the most sanitary input to your program. Anyway this is impressive for a n=1 study. Glad it worked for you.
Also, OP, what materials would you recommend for a machine learning newbie?