If you're counting Weight Watchers points, you want to use the 100 calorie Greek yogurt in this recipe to keep your calories and points down. If you're not worried about counting Weight Watchers points or calories, you can make these Weight Watchers muffins with Greek yogurt that is full-fat or full-calorie Greek yogurt. It will change the points of these WW Carrot Cake Muffins, though. I wouldn't use plain or non-Greek yogurt in this recipe. It doesn't work as well as using Greek yogurt does.