Protein-energy malnutrition (PEM) is a serious medical condition that occurs when the body doesn't receive enough protein and energy to meet its needs. The condition can result in muscle wasting, weakness, and other health problems. Several synonyms for PEM include malnutrition, undernutrition, protein-calorie malnutrition, nutritional insufficiency, wasted (malnutrition), and marasmus. These synonyms are used interchangeably to describe a condition where the body is starved of essential nutrients, leading to serious health consequences. Although PEM is a common problem in developing countries, it can also affect people in developed countries, particularly those who have poor diets or who suffer from chronic illnesses. It's important to recognize the signs of PEM early and seek medical attention to prevent serious complications.