Again, if working all specifics out on your own seems difficult, there are high-quality programs available that help you specify meal composition, serving size, timing of meals and snacks, and even provide you with a shopping list. These programs can be helpful and convenient, but they are not absolutely necessary to achieve your weight loss goals.

Exercise

Exercise is a very important component of any well-balanced weight loss program. In its Guidelines for Healthy Aerobic Activity, American College of Sports Medicine recommends 30 to 45 minutes of moderate aerobic activity performed 3 to 5 times per week. This can be as simple as taking a brisk walk through your neighborhood.

With this as a “base” of aerobic activity, weight training can be an excellent way to burn more calories and encourage development of lean muscle tissue, which burns additional calories even when you’re sleeping! However, it’s important to get qualified instruction in how to perform weight training in order to ensure that you are performing exercises correctly, and not putting yourself at risk of injury.

Another key element in exercise equation is moderation. If you haven’t worked out in a year, you should not set a goal of running for an hour a day, five days a week. Begin moderately and allow your body to become accustomed to this new routine. When you’re used to walking briskly for 30 minutes three days per week, consider increasing to four days per week, and so forth.

Regardless of what specific kind of exercise you choose, if you perform it safely, moderately, and most important, regularly, you will be in a much better position to achieve your weight loss goals. Remember, goal is negative energy balance and exercise is another tool to get you there. If your daily goal is a 500 calorie negative energy balance, it can be much more pleasant to exercise 200 calories away, and only have to restrict your diet by 300 calories.

Conclusion

Successfully combining a healthy diet and exercise program is best way to achieve and sustain your weight-loss goals. A pound of fat represents approximately 3500 stored calories. Using above example of a 500 calorie negative energy balance, over course of a week you would lose approximately one pound, for a total of around 4 pounds per month. Experts agree that this is a healthy rate of weight loss. More importantly, by taking a gradual approach, you are teaching yourself something far more important, which is behavior modification.

Crash diets may promise that you will lose five pounds a week, but if you revert to same patterns of behavior that you were accustomed to before you started your diet, you’ll gain weight right back. No one becomes overweight overnight, so you shouldn’t expect to lose weight overnight either. Allow your body to become accustomed to healthy new habits, so you can sustain your success over long term.

Liz Smith writes about weight loss for thedietchannel.com

I've always been big on analogies, and here's a simple one that I personally use when I "fall off wagon" as far as diet and working out:

Instead of looking at a setback as a total car wreck, look at it as just a minor fender-bender.

You see, although body can be unforgiving, it also has memory, and if you get back to your regime you'll find that you will bounce back and reach your prior level of fitness/weight much faster than it took to get there first time.

So next time you backtrack and put on a couple of pounds, don't throw your hands up in dismay. Instead, do an "Indiana Jones": Put that hat back on, pull down that brim, get that determined look back in your eye and get back on track!