And you're tall.

There is a relationship between height and weight, which is called height and body mass index.

Its formula is body mass index = weight (kg) divided by the square of height (m).

The adult standard value is BMI 18.5-24.9 to calculate the standard weight. Above 25 is called fat, above 30 is called fat, and above 35 is called fat.

Your body mass index is 48÷1.73÷1.73 =16.03.

Below the lower limit of the standard index of 18.5.

There is also a simple calculation method.

Weight kg = height cm-105cm Your weight should be your height 173- 105 = 68kg.

Then calculate according to the height and body mass index.

68÷ 1.73÷ 1.73=22.72

Within the standard weight range.

So you still need to gain 68-48 = 20kg, which is 40kg.

Eat more.