History

• Guidelines posted by the American Dietetic Association recommend that 45 to 65 percent of your total calories should be consumed in the form of carbohydrates. The American Dietetic Association noted that the amount should be at the high end of this range for endurance athletes, such as runners. The Mayo Clinic recommends that you get 10 to 35 percent of your total daily calories from protein.
  
  Despite these long-held guidelines, health authorities such as Dr. Atkins of the Atkins Diet, Dr. Sears of the Zone Diet, and Dr. Agatston of the South Beach Diet have questioned the benefits of high carbohydrate diets for health and performance. This has led to a host of diet plans centered on consuming high amounts of protein and low amounts of carbohydrates.
  
  

Advantages

• According to Caitlin Hosmer, M.S., R.D., L.D.N., of the Brigham and Women's Hospital, the major advantage of a high-protein/low-carbohydrate diet is that it severely restricts refined carbohydrates, such as white bread, white rice, sweets and jams. By restricting refined carbohydrates, you may better control your blood sugar and insulin levels, lose weight and reduce blood-triglyceride levels.
  
  

Disadvantages

• The disadvantages of low-carbohydrate/high-protein diets for a runner are numerous. According to Kimberly J. Mueller, M.S., R.D. and registered sports dietitian, low-carbohydrate/high-protein diets can leave runners mentally drained. This is because when you consume inadequate carbohydrates, your blood sugar drops and the lack of fuel being sent to your brain can cause dizziness, fatigue, headaches and sluggishness---commonly referred to among runners as "bonking." Mueller also notes that low-carbohydrate diets slow muscle recovery, increase the risk for muscle injury during training, trigger joint pain and compromise immune functioning.