It's not all the reasons you mentioned. The main reason is that when you first started to lose weight, you lost too much water and fat, so the effect will be more prominent. Later, with the increase of exercise, the muscles will become strong.

Another reason that can't be reduced is whether the exercise consumption is up to standard, such as time and amount of exercise. Generally, aerobic exercise lasts for 40 minutes and jogging for more than half an hour.

The same is true of diet, not only to eat less, but also to control high-calorie components and carbohydrates.