The simple answer is: yes, you can lose weight without exercising. However, what you must realize is that it isn't the fastest or the quickest way to lose weight. Nor will it help you to keep off the weight you lose long term.
When it comes right down to it, you gain weight when you eat more calories per day than your body burns. To lose weight, you either have to burn more calories than you eat through added exercise. Or you have to eat less calories than your body burns. Combining exercise and diet is actually much easier than just doing one of those two things.
Long term successful weight loss comes from altering both diet and the amount of physical exercise you do daily. Dieting alone can actually slow your metabolism, causing you to burn fewer calories. This is why so many dieters hit a weight loss plateau after a few weeks. This is a big reason to include exercise in your diet plan.
However, for many people this may seem either too difficult, or there is a reason they can't exercise regularly. Perhaps you have a health condition that prevents you from doing any strenuous exercise. Reducing your weight will definitely improve your health, so it is still worthwhile to set up a diet plan that will work for your situation. Here are 2 simple steps that will help you achieve weight loss without exercise:
Begin by finding out how many calories your body needs to maintain its normal functioning. It is fairly simple to work out how many calories you eat per day with one of the many available calorie counters online. Many of these sites also include charts to show you a close estimate of the number of calories your body needs per day according to your height and ideal weight. If you are eating many more calories than this, you will definitely have room to lose weight without exercise.
Now that you have worked out what your calorie maintenance level is you can do some simple math to figure out how to lose a specific amount of weight. On average there are around 3,500 calories to be found in 1 lb. of food. So if you were able to eat 3,500 calories less each week than you are currently eating, you would end up losing 1 lb. Over a week's time, you would need to eat 500 calories less per day.
However, be very sure that the amount of calories you eat per day is not less than the number of calories you need, as you found in Step 1. Don't cut calories below the recommended level, as that is not healthy for your body. Nor will you be able to maintain that type of diet for long. It is much better to lose your weight more slowly over a longer period of time. Extreme low calorie diets will slow down your metabolism, also slowing down your weight loss. They are counterproductive to what you are trying to achieve.
Yes, weight loss without exercise is possible, as we've seen, but it's not the most efficient way to lose weight. A combination of exercise along with a healthy diet will achieve much better results, and usually much faster!