What are two common diseases that result from protein deficiencies?

The answer is marasmus and kwashiorkor.

Marasmus refers to a kind of extreme protein malnutrition featured by a deficiency of energy. It can take place in any person with extreme malnutrition but generally takes place in children. A child with marasmus appears emaciated. The body weight gets reduced to less than 62 percent of the expected weight of the body for the age.

Kwashiorkor refers to a kind of extreme protein malnutrition featured by edema, and an inflamed liver with fatty infiltrates. Intake of enough calories, but with inadequate consumption of protein, differentiates it from marasmus.