Protein is an essential macronutrient. Not only is it important for muscle maintenance and for healthy tendons and ligaments, but protein also forms the structural component of cells and the enzyme that run chemical reactions your body needs to sustain life. In addition, proteins are used to make a variety of hormones you need to stay alive as well as antibodies that protect you against infection. Even oxygen is carried around your body on hemoglobin composed of protein.
Are you getting enough dietary protein to meet your protein requirements? The protein composition of the average person’s diet is between 13 and 15%. On the other hand, certain groups of people who can benefit from a diet that’s higher in protein. Do you fall into one of these groups?
You’re Over the Age of 55
Protein requirements increase after the age of 55. After 55, you need more dietary protein to maintain nitrogen balance. When you’re in nitrogen balance, you excrete about the same amount of protein as you take in. Protein catabolism or breakdown goes up as you age. Unless you compensate by consuming more dietary protein, you may end up in a negative nitrogen balance. Negative nitrogen balance leads to muscle loss and other problems including increased susceptibility to infection. Plus, once you reach your mid-fifties, muscle loss accelerates partially due to hormonal changes. As a result, you need more protein to maintain the muscle mass you already have. According to some studies, muscles become less responsive to a dietary protein with age and need more of this essential macronutrient to elicit an anabolic response.
You’re Trying to Lose Weight
A number of studies show increasing dietary protein helps with weight loss. How so? For one, protein is more satiating than carbohydrates or fats. When overweight or obese people increase the amount of protein in your diet, it leads to greater satiety. Carbohydrates may be more filling initially but protein has a more sustained effect on satiety. In one study, participants who ate eggs for breakfast ate fewer calories later in the day than those that ate a bagel. In addition, protein has greater thermogenic action. When you eat protein, your body has to use more energy to digest and process protein than it does carbohydrates or fats. By increasing the protein composition of your diet, it helps prevent loss of lean muscle mass when you’re consuming fewer calories. It’s fat you want to lose – not muscle, right?
You’re Physically Active
Whether athletes and people who resistance train need more than the recommended amount of protein (0.8 grams per kilogram of body weight) has been an area of controversy. Most research suggests you need more dietary protein if you resistance train, want to build lean body mass and if you do high-intensity workouts or endurance training. Research shows athletes who consume a little over twice that amount (1.7 to 1.8 grams of protein per kilogram of body weight) as part of a resistance training program experience greater muscle development than those that eat the amount recommended for the general population. Even athletes who participate in endurance sports need more protein in their diet than a sedentary person to help rebuild damaged muscle fibers and aid muscle recovery.
You Eat a Vegetarian or Vegan Diet
It’s possible to meet your protein requirements without consuming meat or dairy but it’s a little more challenging. If you don’t consume meat or dairy products, you may need 10% more plant-based protein above and beyond the current recommendations. Why more? Plant sources of protein aren’t as easy to absorb due to their high fiber content so your absorption rate may be lower.
It’s important to choose protein sources that are rich in lysine, an amino acid that some vegetarians and vegans don’t get enough of. Lysine is an essential amino acid that your body needs and can’t make. The best non-meat sources of lysine are beans, lentils, and nuts. If you follow a vegan or vegetarian diet, eat a diversity of plant-based proteins. With the exception of soy, most plant-based proteins lack one or more essential amino acids. You can make up for that by getting your protein from a number of different sources including whole grains, nuts, beans, lentils, and soy.
Meeting Your Protein Requirements
How can you be sure you’re consuming enough protein? Space your protein intake out across the day. Aim for 30 grams of protein at every meal and a protein and carb snack after resistance training to maximize the anabolic response. Of course, you need resistance training to build lean body mass. Resistance training is a “must do” for anyone over the age of 55 to slow down the age-related loss of muscle mass that leads to sarcopenia (age-related loss of muscle mass) and frailty. If you’re an athlete, you may need as much as twice the dietary protein a sedentary person does, about 1.6 grams per kilogram of body weight. It’s still not clear how much additional protein you should get if you’re over the age of 55. Some experts recommend consuming between 25 and 30% more but a clear consensus hasn’t been reached.
The Bottom Line?
Protein is an essential nutrient you may need more of if you fall into one of these groups. Keep that in mind when planning your diet so that you meet your daily protein requirements.
References:
Aging Well. Vol. 4 No. 3 P. 6.
J Am Coll Nutr. 2005;24(2):140S-145S.
Nutrition & Metabolism 2011, 8:68 doi:10.1186/1743-7075-8-68.
Am J Clin Nutr May 2008 vol. 87 no. 5 1558S-1561S.
J Am Coll Nutr. 2005 Dec;24(6):510-5.
Vanderbilt University. “How Much Protein Do Athletes Need?”
University of Maryland Medical Center. “Lysine”
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