If you’re reading this, then you probably have questions about protein and protein supplements. Here are the answers to the most recent nutrition related questions from my friends at the Get Back Up Today Team. Who are the Get Back Up Today Team? They are the first national team composed of people who all live with foot drop. The team includes a triathlete, a marathoner, a teacher and a wounded veteran. Each member has a unique story and different cause of foot drop, including Charcot-Marie-Tooth disease, Multiple Sclerosis, FSHD Muscular Dystrophy and spinal injury.
What is protein and what does it do in the body?
When we eat dietary proteins, they are digested into amino acids. These amino acids form the amino acid pool that the body draws upon to synthesize specific proteins such as muscle, bone, digestive and other enzymes hormones etc. Proteins are a part of every cell in the human body. They can also be used for body fuel if other sources are not available to meet the demand. The body recycles proteins on a daily basis and it is important to eat adequate amounts of protein each day to make sure the amino acid pool is replenished.
How much protein do I need each day?
Recommended Dietary Allowance (RDA): The average daily dietary nutrient intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 percent) healthy individuals.
For most healthy adults the RDA for protein is 0.8 grams of protein per kilogram of body weight. (RDAs for protein in children are higher on a gram-per-body-weight basis than for adults. RDAs also are greater for women who are pregnant [1.1 g/kg/day] or lactating [1.3 g/kg/day]. To calculate your weight in kilograms, divide your weight in pounds by 2.2. Check out this handy DRI calculator for a math shortcut.
How do I get protein in my diet?
Most foods contain protein. Animal foods provide abundant protein but it is very possible to meet recommended protein needs even if you avoid all animal products.
Animal sources of protein:
|Food||Amount||Grams of Protein|
|Fresh Salmon||3 oz.||23|
|Canned Salmon||3 oz.||19|
|Canned Tuna||3 oz.||17|
|Milk (low-fat)||8 oz.||8|
|Cottage Cheese||½ cup||14|
|Greek Yogurt||3.5 oz.||10|
|Food||Amount||Grams of Protein|
|Tofu (soft)||½ cup||8|
|Tofu (extra firm)||3 oz.||11|
|Seitan, cooked||3 oz.||21|
|Soy Milk||8 oz.||8|
|Broccoli, cooked||1 cup||5|
|Spinach, cooked||1 cup||5|
|Quinoa, cooked||1 cup||8|
|Whole Wheat Bread||2 slices||7|
|Lima Beans, cooked||1 cup||15|
|Kidney Beans, cooked||1 cup||15|
|Lentils, cooked||1 cup||18|
|Chickpeas, cooked||1 cup||15|
|Baked Potato with skin||1 medium||5|
|Winter Squash, cooked||1 cup||5|
|Portabella Mushrooms, grilled||1 cup||4|
|Pumpkin Seeds||1 oz.||8|
|Nut Butter||2 TBS||7|
Is there a benefit to a high protein diet?
Not really. An upper limit for protein intake hasn’t been established but there is a limit to how much protein the body can process each day and any additional protein is inefficiently converted to energy or (just like other excess calories) could be stored as fat. Extremely high intake of protein may be hard on the liver and kidneys.
Do endurance athletes require or benefit from additional protein?
Yes and no. Endurance athletes require additional calories to support the increased energy burned in training. An increase in total calories will increases the grams per kilogram of protein without an increase in the percentage of calories from protein. Recommended protein intake for endurance athletes is between 1.2 and 1.4 g/kg/day. Example:
124 lb / 54.6 kg non athlete with intake of 1700 calories per day:
|65% Carbohydrate||12% Protein||23% Fat|
|1105 calories||204 calories||391 calories|
|276 g carb||51 g pro||43 g fat/day|
124 lb / 54.6 kg endurance athlete with intake of 2500 calories per day:
|65% Carbohydrate||12% Protein||23% Fat|
|1625 calories||300 calories||575 calories|
|406 g carb||75g pro||64g fat/day|
|7.2 g/kg/day||1.33 g/kg/day|
Is timing important for protein supplements and intake? Before exercise? After exercise?
Yes, timing matters. To get optimal utilization of protein it is best to spread protein consumption throughout the day as a general rule—to keep the amino acid pool replenished. High protein foods have a slower gastric emptying time so may not be a good choice immediately before or during exercise as GI upset could result. Including protein as part of a post exercise recovery meal along with carbohydrate may boost muscle protein synthesis and recovery.
Is it OK to supplement with protein shakes?
Protein shakes and supplements are intended to add to your overall intake in order to meet your needs. If you are eating enough calories for your activity level and consuming a variety of whole foods, you will likely get all the protein you need. And getting protein from whole food will provide other beneficial nutrients that supplements cannot provide. Protein powders are great for convenience, but it should not be assumed that they are necessary to meet protein needs, even for athletic performance.
How many shakes in a day would be too many? In other words, how much of the DRI should come from food and how much should come from protein supplements?
If you are unable to meet your protein needs with food for some reason and are considering a protein supplement than I would consider how much your intake is currently lacking and supplement accordingly. Nutrition powders and drinks can help provide some of these nutrients but they are not recommended as a total substitute for food, as they lack some of the vitamins, minerals, fiber and phytonutrients found in whole foods and sometimes fall short on fat and carbohydrates. I would encourage everyone to get protein and other nutrients from food so ideally 100% of the DRI should come from food.
What should I look for in a protein shake? What should I avoid?
Here are a few things to be mindful of when comparing the nutritional quality and cost of protein supplements:
- Many of the claims on food packages and supplements are unsubstantiated. Neither the U.S. Food and Drug Administration (FDA), nor any other federal or state agency, routinely tests nutrition powders and drinks for quality prior to sale. They may or may not contain the amount of active ingredient you are looking for (protein) and they may contain ingredients that you might not expect or want (sugar, non-nutritive sweeteners, saturated fat, caffeine, vitamins, minerals or herbs).
- Do the math. You can calculate the expected calories in a product, based on the protein, fat and carbohydrate contents on the label to see if the total calories match the calories actually listed on the label.
- Pay attention to serving sizes, it is not beneficial to meet 100% of their daily needs for protein in one serving. Suggested serving sizes vary widely, ranging from about 10 grams to more than 90 grams per serving among powders, and from about one cup (8 fluid ounces) to over two cups once mixed. Also be mindful of the nutrients provided by the beverage used to mix the powder (milk, juice, water).
What’s the difference between plant-based and other protein? Is one more effective than the other?
There are two common methods for determining protein quality:
1) Calculate the percentage of nitrogen retained or utilized—higher percentage = higher quality.
Percentage of Nitrogen Retained
|Whey Protein||96 %|
|Whole Wheat Flour||64%|
2) Compare to egg albumin, which is thought to have near perfect distribution of amino acids.
Protein Quality Compared to Whole Egg
|Whey Protein Concentrate||104|
I’ve heard that too much soy can be bad for you…is this true? If so, should I avoid soy-based protein powders?
Studies show that soy is a healthy and beneficial food. However if you have a history of hormone receptor positive breast cancer you should avoid isoflavone enriched protein powders, pills, bars and other and supplements. Up to two servings per day of whole soy foods like edamame, tempeh or tofu remain a healthy food choice (One serving averages about 7 grams of protein and 25 mg isoflavones).
One more thing about nutrition and athletes…
Get Back Up Athletes, like all athletes, may benefit from an individualized nutrition plan that takes into account the individual’s health history, the sport he or she participates in, weekly training regimens, time of competition, access to food, and travel schedules. Go here locate a dietitian who specializes in sports dietetics. Go here for a list of Board Certified Specialists in Sports Dietetics.
- American Institute for Cancer Research (AICR). Foods That Fight Cancer: Soy http://www.aicr.org/foods-that-fight-cancer/soy.html#research Accessed July 10, 2015
- ConsumerLab.com Accessed July 10, 2015
- Benardot, D. Advanced Sports Nutrition, Second Edition. Human Kinetics, Champaign Il. 2012.
- Clark, N. Nancy Clark’s Sports Nutrition Guidebook, Fifth Edition. Human Kinetics, Champaign Il. 2014.
- Mamerow MM, Mettler JA, English KL, et al. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. 2014 Jun;144(6):876-80. doi:10.3945/jn.113.185280. Epub 2014 Jan 29.
- Phillips SM. Dietary protein requirements and adaptive advantages in athletes. Br J Nutr. 2012;108(Suppl 2):S158-167.
- Poole C, Wilborn C, Taylor L, Kerksick C. The role of post-exercise nutrient administration on muscle protein synthesis and glycogen synthesis. J Sports Sci Med. 2010;9(3):354-363.
- Tarnopolsky M. Protein requirements for endurance athletes. Nutrition. 2004 Jul-Aug;20(7-8):662-8.
- US Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 27 (revised). Version Current: May 2015. http://www.ars.usda.gov/ba/bhnrc/ndl