TA never sent you a formula because he himself doesn't have one. He's full of shit.
He is busy doing research, that's why he doesn't stay in touch with you via PM's or otherwise? Yeah, you believe that I have a bridge to sell you!!! If you are his research "guinea pig," then you should be in constant contact with him. PM's, phone, texting, whatever. This is of benefit to him as well as you. He should make sure you are staying on your diet and not cheating as to give his "principles" more credit. You should be getting the info from him, this so-called formula and whatever information that you being his subject SHOULD be privy to.
He took you hook line and sinker. But, at least you lost weight and got benefit from the project in some way.