I'm bumping this up again because I just answered another question that boiled down to "calculate your BMR and focus on reducing calorie intake instead of increasing exercise". Do we have a standard question to designate as duplicate, maybe?
Lately, we've been getting a lot of questions along the lines of "I want to lose weight and I do some exercise (examples of moderate exercise) but I'm not losing weight anymore". My understanding is that the state of the art is that exercise by itself does very little for weight loss and that caloric restriction combined with at least moderate exercise is really the key to losing weight for most people. Simply put, without more extreme exercise, the calories burnt are small compared to dietary intake, particularly if people are just eating when they're hungry, which has been shown to lead to people eating more calories than they burned if they're exercising. However, exercise is good for your health in general, and there's evidence that it aids in digestion, particularly if people aren't eating a diet high in all of the varied nutrients needed.
So, long story short, the best possible answer seems to be "do some moderate exercise, but really, let's talk about tracking caloric intake", which seems counter to the focus of this site, but focusing on the exercise seems like it's focusing on the wrong thing for the sake of policy.