Hair loss may occasionally be caused by lack of protein in the diet. Some people who go on crash diets that exclude protein or who have abnormal eating habits may develop protein malnutrition. When this happens, the body will help save protein by shifting growing hairs into the resting phase. Increased hair shedding can occur 2 to 3 months later.
This condition can be reversed and prevented by eating the proper amount of protein and, when dieting, maintaining adequate protein intake. For adults, this means 2 to 3 servings of protein a day. Protein is found in meat, chicken, fish, eggs, some cheeses, dried beans, tofu, grains, and nuts.