Concerning the 'pick of the month' vegetable with Weight Watchers...I don't think that potatoes are the best choice of vegetable to use while dieting, low carbing or not...
Yes, a potato is low in fat, but what happens to all that starch when it is digested? The body turns it into palmitic acid (a saturated fatty acid)...
That, I think, Illustrates the 'low saturated fat, high carbohydrate diet' oxymoron...