Why do some people look thin but heavy

The situation of being overweight but underweight is usually related to high muscle mass, low body fat percentage, or high bone density. There are five main reasons for this: high muscle mass ratio, visceral fat accumulation, heavy bone weight, edematous constitution, and measurement errors.

1. High muscle to body ratio

Muscle density is significantly higher than fat, and muscle weight is about 1.2 times that of fat at the same volume. Frequent strength training or physical labor, with well-developed muscle tissue, can lead to an increase in weight, but visually appear lean. This group of people usually have a lower waist to hip ratio and tight limb lines, belonging to a typical "lean on clothes and fleshy off clothes" body shape.

2. Accumulation of visceral fat

Some people have less subcutaneous fat but excessive visceral fat, which is common in apple shaped bodies that sit for long periods of time. The distribution of visceral fat around organs, although not affecting appearance, can lead to weight gain and metabolic problems. This group of people often have waist circumference exceeding the health standard and require CT or bioelectrical impedance testing for accurate assessment.

3. People with high bone density have a bone weight of about 15-20% of their body weight, which is 3-5 kilograms higher than the average person. This situation is more common in adolescents, athletes, and those with inherited bone mass who frequently supplement calcium. People with thick bones usually have thicker wrist and ankle circumference, but their body fat measurement results are normal.

4. Edematous constitution

Poor lymphatic circulation or high salt diet will lead to fluid retention, which will increase the weight by 2-4 kg without obesity. Facial swelling in the morning and leg pain after prolonged sitting are typical manifestations. This type of weight fluctuation is temporary and can be effectively regulated by improving diet and exercise habits.

5. Measurement Error

There may be a difference of 1-3 kilograms in weight measurement at different time periods, and the measurement results may be higher after a full meal or before menstruation. Wearing heavy clothing and weighing immediately after meals can cause data bias. It is recommended to measure the fasting state in the morning and use a body fat scale to evaluate body composition from multiple dimensions.

It is recommended to confirm the true body fat percentage through professional body fat testing. Muscular physique does not require deliberate weight loss, but attention should be paid to maintaining a balanced diet. Individuals with excessive visceral fat should increase aerobic exercise and control intake of refined carbohydrates. People with edema need to reduce their sodium intake and supplement potassium in moderation. Regular monitoring of waist circumference, body fat percentage, and other indicators can better reflect health status than simply focusing on weight. If necessary, consult a nutritionist to develop personalized plans.