Other people have covered the diet part pretty well. One thing I would add is that for many people eating smaller meals several times a day is helpful. I didn’t make any big changes to my diet. All I did was make better food choices, switch back to the same sort of eating I did in my high school athlete days, and cut portion size a bit. In high school, I ate at least 5 times a day, but I never ate huge amounts of anything at any one time. Switching back to that kind of diet helped me a lot since I was never really hungry. Yes, you never really feel full either, but your body doesn’t do the “feed me NOW” routine that you get if you do many traditional diets.
The portion size cuts were along the lines of cutting the fries from a large to a regular, i.e.: not much in the way of deprivation. Instead of telling myself that I couldn’t have something, I chose another healthier food, or simply cut it altogether. If there was something I truly craved, I’d eat it after a cooling off period, or I’d use it as a reward. Often I never claimed the reward. My problem wasn’t bad eating habits so much as lack of exercise.
Regular exercise is a must. Whenever you can, get back into it. The whole reason I even had to change my diet a bit and get serious about exercising again was because of injuries. After breaking both my wrists (long story) I got out of the habit of exercising, never got around to being my normal semi-athletic self again, and gained a lot of fat over the next two and a half years. When I finally resolved to lose the weight, it took me a couple of false starts and most of a year to lose the bulk of it.
At first, it will hurt a bit, and your mental image of what you can do will be much more ambitious than your physical reality can handle, but you need to get back into exercising again. If you can’t do anything high-impact, don’t do high-impact. Stick to biking, or the elliptical trainer at the gym, or something else that doesn’t strain your knee too much. You should ask your doctor about physical therapy exercises that are suited to regaining the muscle you lost from having your leg immobilized.
Weight training will help immensely with weight loss. My biggest fat losses happened when I switched from a light weight routine with aerobic training to heavy weight training and more moderate aerobic training. You need to do the light weights routine first to get in shape for heavy stuff. Slowly cycle to heavier weight and lower reps. After 1-2 months you should be ready to do relatively heavy stuff and that’s when the fun starts.
A lot of professional trainers and body builders go for 12 week cycles. Even pro athletes break training routines into chunks. The reason they do is so they don’t get bored and so their bodies don’t get too adapted to any one routine. Since you’re trying to establish a habit, you need to focus on a shorter timetable at first, but you’ll eventually be doing a 12 week cycle too. It’s a good time period, short enough to keep focus, long enough to get into a routine.
Start by getting in at least 1-2 days of exercise per week. Schedule time that is explicitly for that purpose. Make that your goal for the week. When you succeed with this modest step, increase it by a day. Keep focusing on that short-term goal until you’re doing at least 3-4 days of good exercise every single week for at least a month to 6 weeks. By the end of the first month, you’ll more than likely be used to the schedule and have a good routine established. Make it to two months and you’re probably going to be habituated; you’ll feel weird if you don’t do your exercise. After that, it takes minimal effort to keep on track.
Breaks are important, especially when you start lifting heavier weights. You shouldn’t work the same body part without at least a 2 day recovery for that body part. You should take at least one day off during the week. Two days are probably better, at least at first. At the end of 12 weeks, take a week off before starting your next cycle. Taking breaks does two things: 1) Keeps you from burning out mentally, 2) Keeps you from overworking. Exercising too much can be almost as bad as exercising too little. Paradoxically, your body will cannibalize muscle for the energy you need to work out if you don’t give it enough time off and enough calories (especially protein) to rebuild energy stores and make new muscle tissue.
Weight workouts should be less than an hour. Aerobic workouts should be short on weightlifting days (15-20 minutes or so) but can be longer on non-weight days. You should not weight train more than 4 days a week. You can do aerobics up to 6 days a week if you want, but if you do your sessions should be under an hour. Thirty minutes is just about right for most people. Any longer sessions than 1/2 hour should probably be limited to no more than 2 per week. Keep your heart rate at 60-80 percent of your max for straight aerobic, do intervals for your short aerobic workouts. If at all possible, separating your aerobic and weight workouts by at least 8 hours will help get better results. Skipping the complicated biochemistry explanation, doing the two kinds of exercise at different times helps you lose more fat, gain more muscle, and allows you to focus your energy and attention on one thing at a time.
This is distilled advice I’ve gleaned from lots of online reading and a couple of books. When I started, I was almost 90 kg (close to 200 lbs.) and had a big belly. Now, I’m down to 80 kg (176 lbs.) with nice visible muscles. I actually put on a couple of kilos from my lowest point when I started to bulk up. I’m semi-addicted to exercise now. I feel like I’m missing something if I don’t get my workout in. Just start out slow, set achievable goals, and keep varying your routine a little and you’ll get there.
It will be WORTH IT. I lost the bulk of my weight from swimming.