The 7 points I mentioned earlier came from a WW exercise points calculator.
Points are calculated using amount of fiber, grams of fat and the calorie content per serving of food. It's difficult to say how many calories a point amounts to since there are three variables in determining that.
If a WW point were 50 calories then anyone weighing 140 lbs or less would only be allowed to eat 1000 calories a day.
Stick with the sliding scale method and you'll be right on.