While drowsiness relates to a need for sleep, fatigue refers to a general lack of energy and motivation. Fatigue is a normal response to physical exertion, emotional stress and inadequate rest, but persistent fatigue can indicate a need for improved nutrition, rest and a low-stress environment. Increasing your protein consumption as part of a balanced diet can help relieve feelings of fatigue and boost your energy level.
Physiology of Fatigue
Fatigue results from both neural stimulation and physical activity, and affects both cognitive and muscular function. While occasional fatigue is normal, persistent or chronic fatigue can be symptomatic of an underlying condition, such as depression, anemia and metabolic and sleep disorders, as well as more serious health concerns, such as diabetes, cancer, bacterial infection and kidney disease. Your level of energy relates directly to metabolism and your body's ability to obtain nutrients from food sources, as well as the efficient delivery of oxygen to all cells, tissues and organs.
Protein, Energy and Fatigue
Proteins are macronutrients made of amino acids required by your body for normal growth and healthy functioning. Proteins comprise the major structural component of all cells in your body, especially the muscles, and are also required for the formation of blood cells. Your body uses dietary protein first and foremost for maintaining and repairing body tissue. When you consume protein in excess of your body's requirements, it is used as a source of energy. Cardiovascular exercise and intense mental exertion both require greater levels of energy, which when not met through dietary sources can leave you feeling fatigued. Anemia, a condition in which your body does not produce enough red blood cells, is characterized by fatigue and weakness. A deficiency in dietary iron, which is obtained primarily through animal proteins, is one of the main causes of anemia and can be remedied by increasing your protein consumption.
Protein for Fatigue
Research indicates that athletes and people regularly engaging in cardiovascular exercise have greater protein requirements to meet their energy expenditure. A review article published in October 2000 in the "Journal of the American College of Nutrition" notes that scientific evidence highlights the need for greater protein consumption among people who exercise regularly. Additionally, a position statement released by the American Dietetic Association in March 2009 in the journal "Medicine and Science in Sports and Exercise" underscores the importance of proper protein intake for athletes. This association between exercise and protein energy has resulted in claims that increasing protein consumption helps heighten energy and dampen fatigue. However, there is insubstantial evidence to suggest that in the absence of protein deficiencies or greater macronutrient need that eating more protein will relieve fatigue. Nonetheless, eating the amount of protein appropriate to your body and energy needs serves to balance blood sugar and prevent fluctuations in energy.
Protein Sources
Your body's daily protein needs depend on your age, sex, health and activity level. Complete proteins contain all nine essential amino acids, and sources include fish, meat, poultry and dairy products. Incomplete proteins, such as legumes, seeds, nuts and grains, lack one or more of the essential amino acids but, when eaten in combination, can provide a complete macronutrient source. For instance, rice and beans when consumed together form a complete protein. To maintain your energy and prevent fatigue, your diet should include a healthful balance of carbohydrates and proteins, with an emphasis on foods low in saturated fat and cholesterol.
References
- Medline Plus: Fatigue
- Reference Biology: Fatigue Physiology
- Oklahoma Cooperative Extension Service: Protein and the Body
- National Heart, Lung and Blood Institute: Anemia
- "Journal of the American College of Nutrition"; Beyond the Zone: Protein Needs of Active Individuals; P.W. Lemon; October 2000
- "Medicine and Science in Sports and Exercise"; American College of Sports Medicine Position Stand. Nutrition and Athletic Performance; American Dietetic Association et al.; March 2009
