It's not necessary to exercise to lose weight, in fact some research shows that exercising too much works against you in two ways.
1. It makes you hungry if you exercise too much (glucose level drops)
2. Many feel the need to 'reward with food' after hard exercise, and over do the food intake or food type. 'I just ran for an hour, surely I deserve an ice cream treat' (most of the calories in ice cream come from fat).
Truth is you can jog for an hour (about 500-600 calories) and do it 7 days a week and only lose a pound (500x7=3500) of -fat- (you might lose more "weight").
But if you cut back 500 calories (two sandwiches) per day, you can lose the same.
I'd say do some kind of movement until you start to lightly sweat (maybe 30 min brisk walking) something you can keep up day after day, and cut back slowly on white carbs, or substitute less fatty meats, and you'll fairly easily drop 1lb/week.