I used the laziest way to get back in shape without dieting. I packed on 10 lbs of muscle in addition to dancing 3 days a week. I was a professional ballet dancer until 2000. I was already dancing that much before adopting the weight lifting program, but I still weighed 195 and wasn't dropping weight. My professional dancing weight was 155 in 2000.
I had refused to lift since the early 1990s because I didn't want too much bulk, but I wasn't losing weight. I knew that the secret weight loss without giving up food (not even junk food) was a higher metabolic rate, and the secret to a higher metabolic rate is muscle mass. A guy who is really muscular or athletic (think Michael Phelps who on some days eats 10000 calories) needs to eat 3500 to 4000 calories just to keep from losing weight. I didn't need to go that far and just 10 lbs of solid muscle boosted my daily caloric requirements to 2500 to 3000 calories. I actually started eating more after adopting a fitness program because I was more hungry, but I still ate less than 3000 calories. The result was that I initially gained 5 lbs but started dropping a consistent 2 lb average a month. Just over a year, I've dropped 22 lbs off the peak of 200 lbs down to 178 lbs. My pant waist size dropped from 34" to 30" and I'm probably around mid to high teens in body fat percentage. I'm still dropping a pound a month now so I'm hoping to get down to 160.
I played football in High School so I was familiar with the basics of weight lifting. All I did to put on 5-10 lbs of muscle was do some basics. That would be bench press, military press, pull-ups, and squats. If you have knee problems, make sure you warm it up and wear the right supports, and probably stick with lower weight, higher repetition, and don't go as deep. Machine lifts aren't nearly as good as free weights.
I broke that down to 4 days and each day I'd do 5 sets of 10 repetitions. Now it's important that you're lifting sufficient weight were you absolutely can't do another one by the 10th rep. You do this for about a month and you'll notice immediate results. You'll initially gain some weight but that's muscle, but you'll immediately notice your pants getting looser around the waste. There are other lifts you can do to work the finer muscles if you get serious about lifting, but the basics are what's important. The basics should take no more than 30 minute per session where you're lifting for 30 seconds and resting 4.5 minutes between lifts.
Note that I didn't do cardio for the first year, though I've adopted an 8-minute run on the 4 days I go to the gym on the treadmill to improve my cardiovascular fitness. That's really not that much and most people at the gym do more than that because they're not as lazy as I am, but 8 to 10 minutes produces some good results so that I'm not winded in any of my other activities. Personally, I think moderation is better for most people because it's easy to stick with. When you do something too strenuous, there's the risk of you giving up the program. Moderation produces some really good results.
So in summary, do 4 30-minute weight training sessions a week, 8+ minute runs, and some other activity you love that isn't as strenuous but spend at least an hour a day and 4 days a week on it. Note that the weight training is the most important aspect of losing fat if you hate doing hours of cardio a day and you hate dieting.