Welcome!
I too have PCOS, hypothyroid, and I also have diabetes.
This diet was actually suggested to me (strongly!) by my sister who is an RN and manages a cardiac rehab unit. (I also have heart issues).
I have one friend who does weight watchers...she's ALWAYS on weight watchers and loses 10 gains it back, loses 15, gains it back cycle. I have maintained my weight for 2 years after finally being able to take off about 30lbs and then tore a couple shoulder ligaments and couldn't work out any longer.
IP is my lifesaver!
That friend on WW... She very much poo-pooed the idea of IP because it's not natural, it's not healthy (what does she know, she's a lawyer, not a doctor!) and that there's NO WAY you can possibly eat so few calories for an extended period of time and not go crazy and jump off the speeding train into the land of eating everything you can get your hands on.
That was a conversation I had with her after 2 weeks on the diet.
I have not had an urge to jump off the train. In fact, after 25lb loss in 2 months, the first massive loss, and the easiest I might add, I've had in years of battling insulin resistance... No way am I EVER going to jump off the train until I either reach my goal, or the surgeon says it's time for surgery (heart)...and then as soon as I can, I'm back to finish off the weight loss!
I have only told my friends and family I'm on the diet. Most are very supportive. My WW friend has actually come around now that she sees my progress.
If you're not ready to argue your point, then I just wouldn't say anything. I don't. I just really like the un-asked-for compliments when they come, and then I say, "Yes, I've lost a few pounds. Thanks!"