Malnutrition Malnutrition is a common and detrimental condition that must be addressed quickly and comprehensively. Registered dietitian nutritionists are working hard to improve the speed and accuracy of malnutrition diagnosis and nutrition interventions in health care. Malnutrition is a physical state of unbalanced nutrition. It can mean undernutrition or overnutrition. When most people think of malnutrition, they usually picture undernutrition, which can be caused by a lack of calories, protein or other nutrients. This occurs frequently in areas of the world without adequate access to food and clean drinking water. Overnutrition comes from eating too many calories. Someone can eat more calories than their body needs and be malnourished at the same time. They may not be eating enough nutritious foods such as fruits, vegetables, whole grains, lean protein, beans, low-fat dairy, nuts and seeds. This can result in vitamin, mineral or protein deficiencies. In the United States, this mo