Although I'm not sure I believe there's a therapist at all, if there is, she may not be lying.
Pause for you all to throw rotting eggs at me.
Fucking hell, who found a rotted ostrich egg...then hard-boiled it? Ow. Anyway, Big Al has any number of logical fallacies built into her thinking, from magical thinking to PHEPH fallacies to the big one, confirmation bias. We see it over and over, a specific statement that can be easily refuted, followed by "you can ask Krystle/Density/Becky" - she knows we can't and anyway, they'd just follow the party line.
CB is (TC rushes off to find definitions so she can pretend she knows something) hearing what you want to hear, having a fixed conclusion which you then lead all "evidence" towards. AL decided long ago she had BED and even if the the therapist only muttered "hmmm..." to the question, she'll hear what she wants; round acceptance. BED gives her an out, whereas we see enough to know she's just an old-fashioned glutton and even plans for binges. Therapy will be useless for her if she's not willing to drop all the fallacies and actually try to see things in a different light, but she has her excuses, her story and her conclusions firmly fixed.
Tl;dr Fucking idiot who is unable to think without falling into well-known potholes. There's a surprise.
Ps. Re: bloodwork - doesn't she claim to be phobic of needles or blood or somesuch? Rafe stabbed her with a tiny glucose check thingie and she screamed the fucking house down. Which is not really a genuine reaction of the truly phobic, but she may have some degree of dumb irrational fear and no balls to overcome it.