Protein Needs Change with Age

Submitted by Amy Sercel MS RD CD

Edited by Marcia Bristow MS RDN CSSD CD

Starting at age 50, your muscle mass begins to decrease each year.  This age-related muscle loss is called sarcopenia.  It's normal and it happens to everyone to some degree.  However, extreme loss of muscle mass can lead to frailty, fatigue, falls, fatigue, and even insulin resistance, all of which can result in a loss of independence for the older adult.¹ Because of this, maintaining muscle mass is crucial for promoting health and longevity as you age.  One of the most important factors in slowing the rate of muscle loss is consuming enough protein on a day to day basis.^2,3

Dietitians used to believe that adults over the age of 18 only needed 0.8 grams of protein per kilogram of their body weight each day.  Recent research, however, suggests that adults over the age of 65 actually need between 1 and 1.3 grams of protein per kilogram of their body weight to support muscle maintenance.  In fact, one study found that adults’ muscle mass still decreased when they were meeting the general recommendation by eating 0.8 g protein per kilogram of their weight every day.³ In more practical terms, this means, once they reach the age of 65 …

·      An adult weighing 130 lb would need 60-76 g protein per day

·      An adult weighing 150 lb would need 68-88 g protein per day

·      An adult weighing 170 lb would need 77-100 g protein per day

·      An adult weighing 200 lb would need 90-118 g protein per day

In addition to getting enough protein on a daily basis, it is also important to be aware of the quality of protein you eat.  All protein molecules are made up of amino acids that link together and determine the protein’s final structure.  There are nine amino acids that your body can’t make, and have to be provided by the food you eat; these are considered essential amino acids.  The other amino acids are considered non-essential, and can be produced in your body.  High-quality sources of protein provide all of the essential amino acids, and some studies show that people don’t need to eat as much protein each day if all of their protein comes from high-quality sources.³

Animal products, such as meat, fish, eggs, and dairy products, provide all of the essential amino acids.  A few plant products, such as soy, quinoa, hemp seeds, buckwheat, and pumpkin seeds, also contain all of the essential amino acids.  You can also combine sources of whole grains with legumes or nuts to create meals that provide all of the essential amino acids.  People used to believe it was necessary to combine these foods within the same meal to absorb all of the amino acids.  Dietitians now know that this isn’t true, and as long as you eat a mix of these foods throughout the day you will meet your essential amino acid requirement.

Studies also suggest that spreading protein intake throughout the day will be most effective for preventing muscle breakdown and maintaining muscle mass. It appears that the ideal protein distribution is about 30 grams of protein at each meal; studies have shown that there is no additional increase in muscle growth when people eat much more than 30 grams of protein at once.^2–4 This means that many adults need to increase the amount of protein they eat at breakfast and lunch, and decrease the amount they eat at dinner.  For example, a day that includes 30 grams of protein per meal would be:

·      Breakfast sandwich with 2 scrambled eggs, 1 oz Cheddar cheese, spinach, and tomato on 2 slices whole grain bread, with an 8-oz glass of milk on the side

·      Lunch: green salad with 2 cups vegetables, 3 oz tuna canned in water, 1 cup canned white beans, and a 6-inch whole grain pita on the side

·      Dinner: stir fry with 1 cup cooked quinoa, ½ cup cooked lentils, 2 oz grilled chicken, and 1 cup mixed vegetables

Lastly, engaging in strength training exercise at least twice per week will also help you maintain a high muscle mass.³ If you aren’t already doing regular resistance exercise, start slowly and work your way up as you build your strength, and consider working with a trainer who will make sure you’re doing the exercises correctly.  This regular activity is crucial for stimulating your body to increase your muscle mass. 

If you're concerned that you aren’t eating enough protein each day or would like support to make sure you're distributing your protein evenly throughout the day, make an appointment with a Registered Dietitian who can determine your unique protein needs and help you create a plan that will fit with your lifestyle.  An ideal plan will allow you to maintain your muscle mass, strength and independence as you get older.

References:

1.         Walston JD. Sarcopenia in older adults. Curr Opin Rheumatol. 2012;24(6):623-627. doi:10.1097/BOR.0b013e328358d59b

2.         Nowson C, O’Connell S. Protein Requirements and Recommendations for Older People: A Review. Nutrients. 2015;7(8):6874-6899. doi:10.3390/nu7085311

3.         Baum JI, Kim I-Y, Wolfe RR. Protein Consumption and the Elderly: What Is the Optimal Level of Intake? Nutrients. 2016;8(6). doi:10.3390/nu8060359

4.         Protein for Fitness: Age Demands Greater Protein Needs. https://www.todaysdietitian.com/newarchives/040715p16.shtml. Accessed October 1, 2018.