You may want to rethink the goal. You clearly like to have a measurable goal, but can you think of some outside of the pounds? Minutes/hours of daily exercise, walking speed/pace come to mind. Some weight loss would follow if you pursue those goals, but the goals themselves would be more attainable - weight loss is not always an attainable goal, which is why so many people carry extra weight. If you are fit, your weight does not matter as much, but again, if you pursue fitness goals, some weight loss would follow. No more than X times a week eating fast food, with X approaching zero eventually, would be another goal.