Let me just say that potatoes are amazing! One medium Russet provides over 50% RDA vitamin C, as well as almost 100mg of magnesium. They have a good amount of protein too. They are a powerhouse veggie, one of the only ones that you could actually completely live on if worse came to worse. It's sad they've gotten such a bad reputation, but its mostly due to what people cook them in etc (like hydrogenated vegetable oils).
For almost 2 years I adhered to a strict very low carb Paleo diet and I kept getting worse and worse. I am allergic to almost every food as well, so eating has been a chore for me too as far as getting enough calories. BUT since I started eating potatoes (and carbs) again, as well as full fat dairy, I am healing at a very very fast rate. I no longer look like a concentration camp resident, I'm back at the gym twice a week. I don't have dandruff anymore, my hands and feet are warm again, and my hair has stopped falling out. I can stay outside in the 90 degree Florida sunshine for a few hours and not feel like passing out anymore. I also have ENERGY. Low carb completely tanked my thyroid and left me starving. Following the advice of all these wacky candida and AF "experts" put me on my deathbed. I'm still working on healing, but it's a far cry from where I was just 3 months ago.
Natway does make sense calorically speaking, but I agree with Mikey about how his approach (like all fruitarians and vegans) needs to change if he wants anyone to hear him out. But I don't have room to talk, I was once one of those preachy vegans :) I'm 5'10 and I'm holding steady at about 145 lbs. I eat about 1500-1800 calories a day now.
Oh, and I eat about 15 pounds of potatoes a week, including crisps which don't bother my gut at all. My gut got so irritated from salicylates that I went into anaphylaxis after a high dose of sals from some tumeric seasoning and couldn't eat anything for almost a month. Crisps were the first thing my body accepted again :) I now follow the Failsafe diet and feel better than I've felt in years