Extended data:
Causes of skin relaxation:
Protein is decreasing due to aging.
There are two kinds of protein in the dermis of the skin: collagen and elastin, which support the skin and make it full and firm. After the age of 25, these two kinds of protein naturally decrease due to the aging process of human body, and the fibers between cells deteriorate with time, making the skin lose elasticity.
Decreased skin support
Fat and muscle are the biggest supporting forces of the skin, and the subcutaneous fat reduction and muscle relaxation caused by various reasons such as aging, weight loss, unbalanced nutrition and lack of exercise make the skin slack and droopy.
Other factors
Gravity, heredity, mental stress, exposure to sunlight and smoking can also change the skin structure, eventually making the skin lose its elasticity and cause relaxation.
References:
Baidu encyclopedia-lose weight