Your body requires protein to create and repair cells, and every cell in your body contains this macronutrient. Performing regular muscle-building workouts increases your protein requirements, but getting more protein than you need won't help you build muscle faster. Excess protein can contribute to problems that could undermine your health and athletic performance. To stay in top form, you'll need a sufficient, but not excessive, amount of protein in your diet.
Your Protein Requirements
By consuming 200 g of protein a day you'll get nearly four times more protein than the average non-athlete adult requires. Men ages 19 to 70 need 56 g protein daily, while boys ages 14 to 18 need 52 g daily, according to the Centers for Disease Control and Prevention, or CDC. Girls and women ages 14 to 70 require 46 g protein a day. You'll need more protein than this to build muscle. At most, however, you'll need 1.5 to 2 g protein per kilo of body weight. That means 200 g of protein a day is only appropriate if you weigh at least 100 kg, or 220 pounds, and regularly perform intense muscle-building workouts. If you weigh less or don't work out, this amount may be harmfully excessive.
Primary Effects of Excess Protein
While most people regularly consume some excess protein with no harmful effects, a large excess of protein can lead to health problems. When your body breaks down protein, it forms nitrogen and urea, a waste product that removes nitrogen. Your body needs water to flush out urea in your urine. More protein causes more water loss, which can lead to dehydration. If you're an athlete losing significant amounts of water through sweat, consuming large amounts of protein increases your risk of dehydration if you don't carefully monitor your water intake. Excess protein, particularly purified protein supplements, takes calcium from your bones, weakening your bones and increasing your risk for osteoporosis. Eating large amounts of animal products for protein increases saturated fat intake, potentially raising your risk for heart disease.
Excess Protein and Your Kidneys
Excess protein makes your kidneys work harder, but it won't damage healthy kidneys. If you already have a kidney condition, excess or even moderate protein intake may worsen it. Impaired kidneys can't remove the same amount of toxins healthy kidneys can. This means too much protein can lead to a build-up of nitrogen in your body. If you have a kidney condition, your health care provider can help you determine how much protein to consume.
Protein from Supplements and Food
Drinking protein shakes to get more protein than your daily requirement isn't necessary to build muscles, explains registered dietitian Andrea Rudser-Ruskin in an interview for Northwestern University's "Medill Reports." If you work out, it's important to get sufficient carbohydrates, your body's main source of energy. Rudser-Ruskin recommends a ratio of 4 g carbohydrates to 1 g protein. Ideally, your protein should come from foods like meat, milk, eggs, nuts and beans rather than protein supplements.
- Centers for Disease Control and Prevention; Nutrition for Everyone: Protein; February 2011
- Columbia University: Go Ask Alice!; Do Bodybuilders and Other Weightlifters Need More Protein?; May 1999
- National Institutes of Health: MedlinePlus; Diet--Chronic Kidney Disease; Parul Patel; October 2009
- Northwestern University: "Medill Reports"; Hold the Protein Shakes: A Balanced Diet is Key to Building Muscle; Kevin Jacobs; March 2010