My blood pressure is 100/70 and I am now down to 223 pounds (from a high, in January of last year, of 300 lbs).
That's awesome! Way to go. How are you doing it?
I eat fewer calories, on average, then I expend. I often eat foods that are high calorie or otherwise bad for me (I've always loved McDonald's), but I eat less of it than I used to.
People act like losing weight is some gigantic time sink that's also really, really complicated. These people are wrong. It is not complicated. Figure out roughly how many calories your body expends, given your weight, gender, and activity level, and then eat fewer calories than that every day. I've hardly added any exercise at all to my lifestyle, either (save a walk for maybe 30 minutes or so most days of the week, but this is a fairly recent addition to my day).
(calories out > calories in) = weight loss.