Which condition is characterized by a deficiency in essential nutrients?

The condition characterized by a deficiency in essential nutrients is malnutrition. Malnutrition occurs when an individual's diet does not provide adequate calories and nutrition, leading to negative health effects. This can involve not only a lack of food but also an insufficient intake of specific vitamins and minerals that are crucial for maintaining health.

Malnutrition can manifest in various forms, including undernutrition, which is the result of inadequate intake of energy and nutrients, and overnutrition, where excessive intake of certain nutrients occurs without a proper balance. It affects physical and mental development, immune function, and overall well-being.

Other conditions listed, such as obesity and diabetes, are associated more with an excess of certain nutrients or energy rather than a deficiency. Anemia specifically refers to a condition often caused by a deficiency in iron or other nutrients that affect the quality and quantity of red blood cells but is a narrower issue than the broader concept of malnutrition. Therefore, identifying malnutrition as the condition related to a deficiency in essential nutrients is accurate.