Well, yes. You need to burn more calories than you are eating.
And the numbers have to pan out. 3500 calories=1 pound of fat. Shave that off your diet, or workout more and you will lose the pound. A combination of both works the best. If you only work with the diet portion, you are likely to lose muscle, lowering your basal metabolic rate. In the long run, when you begin to eat a maintenance amount, you will actually find you gain weight back...what a bummer. If you only exercise, you will find that the weight doesn't budge much, and there is just no way to exercise enough to compensate for a bad diet.
Now, we can get caught up in the minutia. Macro-nutrients and micro-nutrients, different dietary restrictions or fads, etc. But really, a well balanced diet with a good variety of different types of foods, many plant based, will work the best, and utilizing the numbers as a guideline, we can forge weight loss like a well-honed blade. Last week we learned that heavy amounts of meat and cheese are not likely to be healthy choices for longevity, and replacing one dinner a week with a meatless form of protein can be one way to mitigate the risk. Certainly common sense would tell us that too much sugar or salt would be counter productive.
Here's my suggestion: download and use www.myfitnesspal.com. This user friendly program can help you track, calories, fat, carbs, salt, sugar, protein and your daily exercise. Yes, I said DAILY exercise. Because that's really what it's going to take to get there. A well mixed program of daily exercise, some cardio days, some weight lifting days, and some restorative (yoga, pilates) is what is required to see the results you truly desire.