Power of ProteinLast updated: Jun 01, 2013
Throughout your life, your protein needs will vary. For example, infants and adolescents need more protein to support their growth spurts than most adults need to maintain good health. But recent research shows that protein is important as you age.
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What is protein?
Proteins are molecules that are essential for the structure, function, and regulation of cells, tissue, and organs. Proteins make up the structural foundations of your blood, bones, hair, skin, and tissues. They are found in antibodies, enzymes, hormones, neurotransmitters, and DNA. Protein also is an important source of fuel for your body.
Proteins are comprised of smaller structures (or molecules) known as amino acids. The amino acids bind together in a formation much like that of a chain. The order of amino acids in the chain determines the protein’s structure and function.
Each cell in your body contains thousands of proteins that are required for cell function and many body functions. For example, proteins help form blood cells. They carry oxygen in the blood, and they also help transmit messages in the brain that trigger many body functions and coordinate body processes.
You must continue eating protein for good health; and although your body produces most of the amino acids you need, some of them must come from what you eat.
The US National Academy of Science Food and Nutrition Board recommends that most (98 percent of) healthy adults should get 0.8 kilograms of protein per pound of body weight each day to meet their nutrient requirements.1
But recent data suggest that eating more than the RDA-recommended amount of protein can help you maintain and increase muscle and strength as you age ― benefits that are essential for better overall function.2
Because having more muscle and being stronger helps with balance, flexibility, and agility as you age, it can help protect you against falls and muscle weakness that can lead to injuries. Having more muscle can help ensure that you manage daily activities such as lifting groceries, walking up and down stairs, as well as other tasks that help protect your independence. Researchers also have found that getting enough protein can help improve blood pressure, bone health, and boost the immune system.2
The Role of Protein in Weight Loss
Research published in International Journal of Obesity suggests that replacing some carbohydrates with protein can help with weight loss. In the study, participants who ate a high protein diet lost more weight and fat compared with participants who ate the RDA-recommended levels of protein.3
A May 2013 Journal of Nutrition article shows that a diet including 1.2 grams of protein per kilogram of body weight per day (g/kg/d) helped preserve muscle mass and lower blood pressure.4 Other research suggests that high-protein meals have additional benefits, including decreasing appetite.5 One researcher showed she that people who ate a high-protein breakfast felt less hungry and ate fewer calories throughout the day compared with people who ate a high-carbohydrate breakfast. In addition, eating high-protein snacks can help you eat a smaller evening meal.6
The US Department of Agriculture (USDA) recommends all meat, poultry, seafood, legumes (dried beans and peas such as lentils, peas, and garbanzo beans), eggs, tofu, tempeh, nuts, and seeds are excellent sources of protein. Milk, cheese, and yogurt also are good sources of protein. Soy milk and soy products as well as nut milks and rice milks can help boost your protein intake.7
The National Academy of Science recommends that adults eat 15 percent to 20 percent of calories from protein to preserve muscle mass, feel full longer, help with weight loss, and promote good health.1
Protein-packed foods that are ideal for meals and snacks include:
Food/amount/protein in grams7,8
Greek yogurt, 6 ounces = 11
Milk, 1cup = 8
Cheese, 1 ounce = 7
Chicken, meat, or seafood, 1 ounce = 7
Nut ¼ cup = 7
Tofu, 5 ounces = 12
Legumes ½ cup = 7
Egg, 1 = 7
For high-protein meals and snacks, try these options:
- Scrambled egg whites, whole grain toast, and fruit
- Peanut butter or almond butter stirred into plain oatmeal made with fat-free milk
- Greek yogurt topped with fruit and a sprinkle of nuts
- Turkey sandwich on whole grain bread with a glass of fat-free milk
- Lentil soup and a tossed salad with nuts and seeds
- Stir-fry with tofu, vegetables, and peanuts
- Grilled chicken and vegetables
- Salmon with boiled potatoes and a tossed salad
- ½ cup of low-fat cottage cheese with ½ cup of fruit
- Hummus with raw vegetables
- One slice of whole grain bread with 1 teaspoon of peanut butter
"It's important to balance your protein, carbohydrate, and other nutrient needs with a healthy number of calories each day," says Summit Medical Group registered dietitian Susan C. Canonico. "A nutritionist can develop a sensible eating plan that ensures you get the nutrients you need within calorie limits that help prevent you from gaining unwanted pounds as you age."
For more information about protein and other dietary needs,
call Summit Medical Group Nutrition Services today
1 Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (macronutrients). 2005. http://books.nap.edu/openbook.php?record_id=10490&page=589. Accessed June 1, 2013.
2. Wolfe RR, Miller SL, Miller KB. Optimal protein intake in the elderly. Clin Nutr. 2008;27(5):675-684.
3. AR Skov, S Toubro, B Rùnn, L Holm and A Astrup. Randomized trial on protein vs carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Inter J Obes. 1999;23:528±536.
4. Soenen S, et al. Normal protein intake is required for body weight loss and weight maintenance, and elevated protein intake for additional preservation of resting energy expenditure and fat free mass. 2013;143(5):59106.
5. Heather J. Leidy et al. The influence of higher protein intake and greater eating frequency on appetite control in overweight and obese men. Obesity. 2010; 18(9):1725–1732.
6. Leidy JH et al. Beneficial effects of a higher-protein breakfast on the appetitive, hormonal, and neural signals controlling energy intake regulation in overweight/obese, "breakfast-skipping," late-adolescent girls. Am J Clin Nutr. 2013;97(4):677-688.
7. Protein Foods. USDA choose my plate. http://www.choosemyplate.gov/food-groups/protein-foods-why.html. Accessed June 1, 2013.
8. Dairy: health benefits and nutrients. USDA choose my plate. http://www.choosemyplate.gov/food-groups/dairy-why.html. Accessed June 1, 2013.