I can relate so much. My parents were on a strange version of SBD after I lost so much wieght. The live a few states away, so I was coaching my mom through the beginings of it, sending her emails. Talking with her on the phone practically everyday trying to help her plan her meals. They both lost a ton of weight, for awhile.
I went to visit them about 6 months later and found what they really were eating! OMG, my dad was eating a
big bowl of ice cream everynight along with cookies and chocolate candy. On top of the ricotta cream desserts, they were using the full fat dairy because the lf stuff was so expensive. And then my dad has the nerve to tell me "your diet was making me fat."
My dh for the longest time when people would tell him I looked good losing the weight would go on about ketosis and low carb eating. No matter how many times I told him that it wasn't a low carb diet.
Or the people who go on the beach for a week and then go off because they gain weight, when you ask them what they ate it was basically 100% fat because all they ate was eggs, cheese and nuts by the pound each day. Did you not read the book?
Don't you want to strangle people sometimes?
He has no idea. I have handed him the book. I have printed out the lists. He just doesn't know! I will continue to make acceptable meals, but I cannot support that he thinks he is actually following this diet. 
