I lost weight over a year period. I am very close to being a vegetarian. No red meat fried foods. I eat lots of veggies chicken and fish. I have kept it off for over a year now. I do the treadmill 3 or 4 times a week walking jogging. 30 minutes at a time. Then I do a little weight lifting.
I'm not a big fan of treadmills however for two reasons: (1) you can't get aerobically fit by walking and (2) running bangs the h$ll out of the old legs. Biking on the other hand, whether outside or on a trainer inside, is a "no impact" exercise (unless you fall off) and there is no limit to how fit you can become.
A friend of mine down the street recently bought a bike (a couple of months ago) and rides for an hour a day three days a week at a pace that is comfortable...and he tells me he is astonished at the transformation in terms of fitness. He is 45 and never exercised previously and weights around 280. He says he has only lost 10 lbs, but he has lost inches and feels terrific.
With regard to weight training, I keep 20 lb handweights and a bench in my office (I work at home) and, whenever I get tired of sitting and working, I do a quick set of whatever comes next. I find this kind of workout gives me a much higher level of tone because I don't compress it into a specific period. Also, I have found that if your goal is muscle tone instead of bigness, you can work out every day instead of every other day. I only give myself a rest day if I feel soreness or if I feel a little tired. Otherwise, pump away.
Aerobic fitness on my bike is my real love. I had a trainer many years ago that told me to seek the sweet spot when biking. He described that as that level of exertion that is just hard enough to leave you feeling strong enough for a push or a hill and not so easy as to be boring. I always save enough energy back for a kick in the last 15 minutes of a ride.
For anyone just starting out biking, I would suggest that you take it easy and enjoy it. Slowly but surely you'll find you body will want to push it as you sock on the miles. There was an adage years ago about running that suggested the best way to run was "long slow distance." That worked for me when I was a runner and it works even better in the bike saddle.