Sun suggested Amy to lose weight by improving basal metabolism through hot compress and weight loss. But simply improving basal metabolism can't keep fit for a long time, because the calories consumed by the human body are basically constant. If the intake of calories exceeds the daily needs, it will cause heat accumulation and lead to weight gain.
Therefore, if you want to maintain your ideal body shape, you need to comprehensively consider many factors such as diet, exercise and living habits. Sun advised Amy to lose weight, although it had some effect, but it could not replace a healthy lifestyle and eating habits.