If you're keen to lose weight, then you can quite probably do it without needing to exercise. Modifying your diet and eating less are often very effective ways of losing weight. But if you plan to keep your new, trim body for the long term, exercise will need to become part of your life.

Studies have shown that people who exercise are far more effective at maintaining their weight loss levels. Around 90 percent of people who've kept their weight low have included exercise in their program. However, of those who don't exercise, around 90 percent put all their lost weight right back on again. Often they gain even more.

To keep your lost weight off for good, you need to find a healthy balance. Combine eating well with a regular exercise program, and you have a much better chance of keeping that excess weight off. Sometimes it doesn't take a lot - perhaps have one scoop of ice-cream instead of two, and make sure you go for a nice long walk as well.

Despite all the advertisements that try to sell us the idea that losing weight can be quick and easy, the reality for most of us is that it requires a lot of time and commitment to make a serious difference to our weight. This is even more the case once you’ve lost weight and want to keep it off. If your genetics are against you, then you need to work even harder.

So taking a 15 minutes stroll once or twice a week probably isn't going to be enough. Instead, you need to do between 30 and 45 minutes of aerobic exercise 3 to 5 days a week. It might sound good to just drink a healthy shake for breakfast and all your weight loss worries are over, but it's not reality for most of us.

Another thing to remember is that once you've lost the weight, stop dieting. Although there are plenty of diet plans that are great for losing a lot of weight quickly, if you try to continue the diet plan long term, you may well damage your overall health.

Also, choose a form of exercise that suits your level of fitness and health. Don't you just love those ads that tell you a particular treadmill will help you burn over 1,000 calories per hour? Have you ever tried to do that? Most of us would fall off in about 30 seconds flat, and probably need help from a paramedic to get back up again. Even the fittest person would struggle to actually workout at that level for an hour.

In the long term, keeping weight off is all about moderation. Find a sensible, balanced eating plan that provides all the nutrients you need without stacking up the calories. Develop an exercise program that incorporates activities you enjoy and make sure you do them most days of the week. If you stick to this plan, you will find it much easier to stay trim and healthy.