Apples and whole wheat bread generally contain only the body's necessary vitamins, water or fiber, if the calories are not supplemented, it will break down the body fat to produce calories, so from this point of view, you said this approach to weight loss is effective.

But I would say that this is not a scientific way to lose weight, much less a healthy one, and I personally don't recommend it at all. You're talking about dieting, but dieting not only breaks down fat, it also breaks down muscle, and there's even a risk of anorexia, so is that really what you're looking for?

If you want to lose weight, on the one hand, pay attention to diet, on the other hand, you also need to strengthen the exercise, so that the consumption of calories is greater than the intake of calories. As for diet, the human body must have protein, amino acids, vitamins, carbohydrates and minerals, etc. In order to ensure a balanced intake, you can choose the corresponding low-fat beef, soy products, fruits and so on. As for exercise, if you usually do not like sports, you can choose to run half an hour a day, which is the most convenient and simple aerobic exercise, when you develop such a habit, after a certain period of time to adhere to, will be able to reap the desired results, go!