I think we basically agree, it's very easy to miss high calorie foods that can totally throw your calculations out.
And you shouldn't use a slow metabolism as an excuse for accepting a certain state, maybe that's easy for you and me to say as we both seem to be lucky enough to be healthy.
But since you can alter your metabolism it can be a useful tool as part of weight loss. Do weights, increase muscle mass, increase metabolism, lose weight. In terms of time spent weights are very effective as well - 3-5 workouts of 45mins per week is plenty.
Actually, and that is my point entirely, luck isn't the word. I have shitty genetics (I think on both sides, for the last 2-3 generations my family has been overweight/obese). Heck, during my wife's pregnancy there were complications, and due to stress + bad food + no exercise I ballooned up 9 kilos (20 pounds) in about 2.5 months. If I don't take care of myself, I gain weight quite easily.
And not to try to be the naysayer, but the effect of muscle on calories burned at rest has been quite the myth floating around. Check the references at the bottom of http://www.lanimuelrath.com/blog/calories-burned-by-muscle-v... and you will see that 10 pounds of extra muscle will burn at most 60-70 more calories than fat at rest.
Apart from that, I agree, do weight training 3-5 days a week. move around, eat healthy. That should be enough to at least get you to the normal weight range.
And you shouldn't use a slow metabolism as an excuse for accepting a certain state, maybe that's easy for you and me to say as we both seem to be lucky enough to be healthy.
But since you can alter your metabolism it can be a useful tool as part of weight loss. Do weights, increase muscle mass, increase metabolism, lose weight. In terms of time spent weights are very effective as well - 3-5 workouts of 45mins per week is plenty.