Say the word “protein” and it likely conjures up everything from Paleo and Atkins diets for weight loss to soy protein for heart health and whey protein for muscle building. At the other end of the protein spectrum are claims that too much can harm your kidneys or that the key to good health is to avoid animal protein and focus on eating only plant protein. The science behind how much and what type of protein your body needs is really complicated. But the tide seems to be shifting as more and more researchers suggest one simple fact: For most of us, protein needs are greater than called for by current dietary recommendations.
Protein Points to Remember
- You need more high-quality protein as you get older.
- Protein should be divided among meals.
- Aim for 25–40 grams of high-quality protein
per meal; less than 15 grams won’t benefit bone or muscle.
- Get plenty of calcium (1,000 – 1,200 milligrams/day) along with protein.
- Use caution with high-protein diets if you have kidney disease. While a high protein intake won’t cause kidney disease, it can be harmful if the kidneys aren’t functioning properly.
Recommended Dietary Allowance for protein. The Recommended Dietary Allowances (RDA) say adults of all ages should have a protein intake of 0.8 grams (g)/kilogram (kg) body weight/day (to calculate protein needs, multiply .8 by your weight in pounds and divide by 2.2; that’s 55 g/day for a 150-pound person). This is based on the amount of protein required to avoid a deficiency. However, researchers now believe that diets that provide more protein than the RDA may improve health by helping to prevent obesity, osteoporosis, type 2 diabetes, and metabolic syndrome (Nutrition & Metabolism, 2009.)
“When we’re young, hormones help us use dietary protein very efficiently for growth; adults need more dietary protein to maintain healthy muscles and bones”—necessary for energy balance, blood sugar regulation and bone health—says protein researcher Donald Layman, Ph.D., Professor Emeritus in the Department of Food Science & Human Nutrition at the University of Illinois in Urbana.
Protein needs increase with age. While the current RDA for protein stays the same regardless of age, the amount of protein intake becomes even more important as we age. Calorie intake often decreases with age, but protein requirements do not. A recent report on the protein needs of older people concluded that to maintain physical function, healthy older people need more dietary protein than younger people—in the range of 1.0 g/kg to 1.2 g/kg/day. That translates into 68–81 g of protein/day for a 150-pound person (Journal of the American Medical Directors Association, 2013.) Older people who are acutely or chronically ill need even more—1.2 g/kg–1.5 g/kg/day (81–102 g of protein/per day for that same 150-pound per-son).
The bottom line? Protein needs are based on weight, not calorie intake, so even if calorie intake drops, protein intake should stay the same or increase as you age.
Potential benefits of more protein. Protein makes up about 50 percent of the volume of bone and one-third of its mass (American Journal of Clinical Nutrition, 2008.) While there has been a widely held belief that high-protein diets were bad for bones, causing calcium to leach out and leading to osteoporosis, research now suggests that calcium and protein intake interact to actually improve bone health. As part of the Framingham Offspring Study, researchers found that greater protein intake may benefit bone health in older women, especially those with lower calcium intakes (Public Health Nutrition, 2013.)
Researchers also are discovering that the way in which dietary protein is distributed throughout the day is important. To maximize the muscle-building and help prevent bone loss, daily calcium intake should be adequate (1,000 to 1,200 milligrams/day) and protein should be provided with each meal.
Getting more high-quality protein. If you’re trying to manage your weight or simply eating less than you used to, getting enough protein is even more important for your overall good health. Here are a few examples of high-quality proteins to include at each meal:
- Beans (7 g/½ cup)
- High-protein breakfast cereals
(up to 13 g/1 cup)
- Eggs (7 g/1 large)
- Skim milk (8 g/cup)
- Lean beef and pork (21–24 g/3 ounces)
- Nuts—peanuts, pistachios and almonds are highest (6–7 g/1 ounce)
- Veggie burgers (11–15 g each)
- 100% Whey protein powder added to smoothies and shakes (up to 24 g/1 ounce)
- Greek yogurt (12 g/5 ounces)
How much protein per meal? Researchers suggest about 25–40 g of high-quality protein (proteins that provides all the essential amino acids) at breakfast, lunch and dinner (Current Opinions in Clinical Nutrition and Metabolism Care, 2009.) Small meals that contain less than 15 g of protein, says Layman, provide no benefit to muscle health.
“Ideal protein intake doesn’t mean extra large serving sizes,” he says, “but 25 to 40 grams of protein at each meal. A balanced diet should provide proteins from a mixture of foods that may include milk, meats, eggs or beans.”