I'm not a fan of TV, so, maybe that is where we differ. I like movies and music, but, watching mind-numbing TV inside is painful to me.
I'm pretty familiar with training, recovery, and how different diets and regimens influence that - not an expert, but, as someone who has put the chaulk on my hands I've learned a few things from people who are better lifters than I am....and through lifters I've talked to my fair share of doctors, trainers, from all walks of sports.
Cardio is often confused with aerobic fitness or endurance. Aerobic/endurance fitness relates directly to the efficient of oxidative metabolism and is not the same as cardiorespiratory fitness (a healthy heart and lungs). Aerobic fitness like running burns calories, but it does for that time period. The advantage of lifting is the muscle gained lets you burn more ALL the time. As far as health, in the practical sense, when lifting weight, the cardiovascular system is stressed. One of the first is that the contracting muscles compress the blood vessels in those muscles and increase their reistance to flow. This increases blood pressure. This places load on the heart, which over time strengthens it like any other muscle, and it adapts by increasing the thickness of the muscular walls and the increased muscle mass of the heart makes it deliver blood more efficiently. It needs to, because as muscle mass increases.
Anyways...
My arguement isn't that running on a treadmil or something is bad, it's just that it is mentally and physically expensive for what the opportunity costs are (in my opinion). For a busy life, to burn 300 calories running every day gets to be inefficient. To train for an hour three times a week, using basic exercises that work the body as a system, gives you some calorie burning, but also the added strength and muscle mass that helps in regular life. For being more 'active,' doing (to use the venacular) cardio could be doing something fun like washing a car, having wild sex if possible, cleaning, tinkering, moving speakers, or whatever.
Eating 'decently' (shoot for a 40/40/20 diet, protein/carbs/fats ... good fats like natural peanut butter or roasted almonds, not bad fats), but normally (not fretting having a cheeseburger and a beer with your friends, just don't have a cheeseburger, cheesefries, 12 beers and a fudge sunday), and working out (HARD) three times a week for an hour (or whatever program you decide, just keep it simple - simple not to be confused with easy... simple in weightlifting is the hardest), and being active in normal life is, in my opinion, the best way.
For my buddy, I'd recommend starting with working on the low hanging fruit. Cut out garbage food, and starting making the obvious choices. Go for a walk, try to be more active, and see how it goes. As it was said earlier, this is going to be a lifestyle change. So no starving, no radical or not-maintainable ideas.