Why doesn't weight loss cause weight loss, but waist circumference has decreased

During the weight loss process, it is normal for weight to remain unchanged but waist circumference to shrink, which is usually related to factors such as muscle growth, changes in water content, and alterations in fat distribution. The decrease in body fat percentage and visceral fat is the key reason for waist slimming, and weight scales cannot directly reflect these changes in body composition.

Muscle density is greater than fat density, and when losing weight through exercise, fat may be consumed while muscle mass may increase. Muscles of the same volume are much heavier than fat, which can result in less noticeable weight changes or even an increase, but the body shape will become tighter. The combination of strength training and aerobic exercise can easily cause changes in body composition, with waist and abdominal fat being more sensitive to exercise stimulation and often being consumed first. Some people may experience water retention during the early stages of weight loss, especially women who experience significant hormonal fluctuations before and after menstruation. A high salt diet or sudden increase in exercise intensity may also lead to an increase in water storage in the body, masking the weight loss caused by fat loss. Waist circumference, as a direct indicator of abdominal fat accumulation, can more sensitively reflect the reduction of visceral fat, and the health benefits of visceral fat reduction are much greater than subcutaneous fat.

It is recommended to use multiple methods such as body fat scale, skin fold thickness measurement, or regular photo comparison to monitor weight loss effectiveness and avoid relying solely on weight data. Maintaining a moderate calorie deficit, increasing protein intake to protect muscles, and combining with core muscle training can further optimize waist and abdominal lines. Measuring waist circumference once a week and recording trends can provide a more scientific assessment of weight loss progress than daily weighing.