Unfortunately sport is necessary to loose weight in a healthy way. Diet as such can only support this process but moving your body is essential. Try a sports you really like so it is easy to keep yourself motivated. Dedication is the most important part when it comes to weight loss.
For me...
Those posts are really good for my motivation, thanks! I really am in bad phase at the moment. I cant do lots of sports at the moment because i have an injury on my knee. Maybe playing this sport game will lose me some calories, too :(