Weight loss is more complicated than that. Your question is rather simplistic. For one thing, you can't live on ice cream. For another, there are many factors involved: the dieter's activity level; his or her metabolic rate. Not only how many calories you take in and how many you burn, but what kind of calories they are. You see, your body doesn't handle fat calories the same way it does protein or sugars or fiber or--? The human body is a curious, wonderful, and mysterious thing. Your best bet is a sane, healthy program like Weight Watchers. I love it. 75+ pounds worth!
Don't get on that Roller Coaster. It's too hard to get off. And there's not enough time in your busy day to keep up the amount of exercise to SAFELY lose the calories!!! Right now you plan to exercise it off; next week you'll try to take diet pills to get it off!! See where I'm going? Eat everything in moderation and be happy! :-)