I forgot to mention sweet potatoes. As for new or the little red potatotes, my gastrointestinal doctor gave me a a list to follow as for what foods to eat which is a low-carb list of foods that don't break down into sugar as easily and digest more slowly. He said the new or little red potatoes didn't have the starch content (which breaks down into sugar) that the white potatoes have. I'll double check this with them and also do some research on my own. I know someone on here mentioned they go by the 40-30-30 diet; I got the book from this doctor (you can get it at a bookstore or online too).
Btw, Dave, if you are putting on weight by eating the little red potatoes, you are either eating too much of them or putting stuff (butter, margarine) high in calories/fat on them. I suggested olive oil to you (lightly drizzled). It is a better oil, like canola oil, than vegetable oil. But as with any oils or food for that matter, moderation is the key. Stay away from things that have partially hydrogenated or hydrogenated oil in them--not good for you. If you like peanut butter, use the natural peanut butter(s).
My doc also suggested that if you have rice, pasta or potatoes or bread one day, skip having any the next day.