**Marasmus: Causes and Explanation**

**Introduction**
Marasmus is a severe form of malnutrition that primarily affects children. It is caused by a prolonged and severe deficiency in calories and essential nutrients. The condition is characterized by significant weight loss, muscle wasting, stunted growth, and overall depletion of body fat and muscle mass.

**Causes of Marasmus**
Marasmus is primarily caused by a diet insufficient in calories and essential nutrients. This deprivation results in the body not receiving adequate amounts of energy and essential nutrients required for proper growth and development. Among the essential nutrients, the deficiency of proteins, carbohydrates, and fats play a significant role in the development of marasmus.

**Insufficient Proteins**
Proteins are the building blocks of the body and are essential for growth, repair, and maintenance of tissues. Inadequate protein intake prevents the body from synthesizing and repairing tissues, leading to muscle wasting, weakened immune system, and impaired organ function. As a result, children with marasmus often exhibit severe muscle wasting and decreased strength.

**Insufficient Carbohydrates**
Carbohydrates are the primary source of energy for the body. Inadequate carbohydrate intake deprives the body of energy, leading to a state of constant energy deficit. This deficit hampers the normal functioning of various bodily systems and impairs growth and development. Lack of carbohydrates in the diet can contribute to the depletion of body fat stores and a decrease in overall body weight, which are characteristic features of marasmus.

**Insufficient Fats**
Fats are essential for the absorption of certain vitamins, hormone production, and insulation of the body. Inadequate fat intake leads to a deficiency of these vital functions. Furthermore, fat stores in the body act as a reserve source of energy. In the absence of sufficient fat intake, the body resorts to breaking down muscle tissue for energy, exacerbating the muscle wasting seen in marasmus.

**Conclusion**
In conclusion, marasmus is caused by a diet insufficient in proteins, carbohydrates, and fats. The deficiency of these essential nutrients leads to severe malnutrition, resulting in weight loss, muscle wasting, stunted growth, and overall depletion of body fat and muscle mass. It is important to address these dietary deficiencies and provide adequate nutrition to prevent and treat marasmus.

Correct is D.
Marsasmus is caused due to diet insufficient in proteins, carbohydrates and fats.