What are the different stages of malnutrition?

When it comes to weight loss, two degrees of severity must be distinguished: In the first stage (weight dropping below 80% of normal weight), there is a reversible reduction in adipose tissue and skeletal muscle mass. In the second stage (a decrease in body mass index to below 18^kg/m²), cachexia may develop, which is associated with further loss of muscle mass and a reduction in important fat stores. This second stage is irreversible and should be prevented through effective nutritional support.