Of course what you put into the body will have the major influence of all. May want to drop the carbs down to 300 grams the first weeks. The second week, down to 200 and the following week 100 grams a day. You want to start this process slowly, advoiding the crash diet disaster of doing things too quickly. After that 100 grams week is pasted than control the carb intake around the 40 gram mark for as long as you wish to stay on a weight lost plan. I would not suggest a zero carb diet at any time, though it has worked for some. Recommend a good vitimin/mineral/herb supplement daily along with a fish and/or flaxseed oil based cap. Drink lot's of water throughout the day. Your protein supple should be up quite high because of the increased fish, chicken & meat consumption. May also want to do some serious reading/research before undertaking any eating pattern that is 180 degress different from what your use to.
Running, threadmills, etc may not be the best choice at this point. At 41 and all that added weight, the feet, ankles, knees, lower back/hips may be given more stress than needed. Might consider short intreval cardio programs as the Tabata method or like training. Air-Dyne, Spinning, rowing and other forms of sitting/reclining machines offer good cardio workouts. Don't know if the Duncan YMCA in Chicago still offer's BB'ing/weight lost programs but I've been told by quite a few in the training field/profession (more expert than I'll ever be) that they are one of the best in the mid-west.
A book that I may suggest is Challenge Yourself by Clarence Bass. Quite a few Tri athletics around here (SD) follow a similar training style. Not that you want to become a Tri preformer but it has some very good weight loss/endurance/BB'ing advice for any age. It's not the low carb thing but a different angle of weight loss and muscle gain. Any BB'ing training plan can be converted into a cardio workout with less rest between set's and exercises and still build muscle mass. The old PHA and Circuit Training also come to mind.
I weighted 280 or so in college (senior year) when playing football at 6'2. I'm 33 now and weight 235. Thing is, my chest now is the same size as when I was 280 and the waist is a hard 36". Don't know what your playing weight was, but your first goal might be to drop down to your college weight as the first phase of your weight loss plan. Good Luck.