As a trainer, you've heard it all when it comes to protein. There are myths galore about protein, from too much is damaging to your body to the idea that protein isn't important unless you're a serious lifter. Let's take a closer look at the function and role of protein, controversial myths, and offer some tips on protein intake. Then, you'll be able to answer the question, how much protein do I really need.
Protein is an essential nutrient that plays a huge role in helping to keep clients healthy. Further, it's essential to building muscle mass. While some clients might be quick to jump on a high protein diet, others might do the opposite due to preferences or belief in myths. Either way, dietary protein consists of amino acids that are responsible for everything. For example, our structure, hormones, enzymes, and immune chemicals all need protein.
Because there's such an ongoing functional need for amino acids, keeping a consistent pool of them is like keeping a sink full without a drain plug. They're constantly lost as they're broken down which means there's an ongoing need to consume a diet high in protein rich foods. This is especially the case in goals that involve muscle growth and weight loss. Our clients must realize protein supplies the building blocks of muscle and connective tissue (like ligaments and tendons). So, in the case of resistance training, the body is intentionally breaking down muscle tissue to force it to adapt and build bigger or stronger lean body mass. Therefore, achieving a specific protein intake each day is essential for health, fitness, and weight loss goals.
Oftentimes, clients looking for weight loss will consider a low-carb, high-protein diet. When successful, people sometimes think it's the absence of carbs from the daily calories that achieved the results. However, meeting the right protein requirements is beneficial in two ways. The first is that protein consumption reduces client's appetite. This is because calories from protein take longer to breakdown than most carbs and fats. Consequently, clients will feel fuller longer when eating a diet consisting of high-quality proteins. This result of appetite reduction is commonly called spontaneous reduction in calorie intake. All it means to your client is they'll be feeling fuller longer and therefore less likely to eat and snack at unnecessary times.
We already mentioned the need for protein to support the maintenance and growth of lean mass. Clients who have more muscle tissue have a higher resting metabolic rate because muscle burns more calories than fat to survive. A higher resting metabolic rate means more calories burned each day. Basic weight loss principles tell us more calories burned means more weight lost. So, this is the second reason why daily protein intake is important for body fat reduction.
You likely already know some of this, but you need to be able to convince your clients and people who ask you for fitness and nutrition advice. Tell them why getting enough high-quality protein is so important:
Protein builds muscle mass
Adequate protein benefits post-workout recovery
Protein in the diet supports fat loss
Protein is important for a healthy immune system and connective tissue
Insufficient protein skews body composition
So, we know protein is good and necessary, especially for active clients. But can there be too much of a good thing?
Sure, too much of anything is always possible, but with protein intake, that danger level is much higher than most clients realize.
Even though you know the benefits of protein intake, your clients still might resist. In fact, they might say they've heard that protein is damaging to both the kidneys and bones. You'll learn the facts about these two myths here.
Think of the kidneys as the body's water filter. They get rid of unneeded substances, metabolites, and other waste from the body. Yes, they play a crucial role in metabolizing and excreting the nitrogen byproducts from protein digestion. But, this doesn't mean that eating extra protein will overtax a client's kidneys.
One reason this myth has perpetuated is that research has shown a high-protein intake can increase how hard kidneys work—for people who already have chronic kidney disease and damaged kidney function.
Multiple studies concluded that healthy individuals will NOTdevelop kidney disease or impaired kidney function from increased protein intake. [2,4,]
To get into a little more detail, researchers found increased protein intake does change how your kidneys function, leading to hyperfiltration—but this isn't a bad thing. Hyperfiltration is evidence that the kidneys are adapting to higher protein levels in the diet. They are simply doing a better job of metabolizing increased amounts of protein.[1,2,4,]
Think about people who have donated a kidney. The one kidney left over suddenly must handle more protein. If higher levels of protein damaged healthy kidneys, we would see it in donors. But we don't. That one kidney just adapts and donors have no increased risk for kidney disease.
Further, researchers have found that bodybuilders and other athletes who consume high-protein diets are also not at a greater risk for kidney damage or disease. These people may consume more than 2 grams of protein per kilogram of bodyweight, much more than the average person eats per day.
The idea of protein leading to weaker bones comes from the fact that protein increases the acidity of the body, and that this causes calcium to leach from the bones to counteract it. Excess acidity can to lead to bone weakness, but protein is not the culprit. 
In fact, protein in the diet has the opposite effect: it strengthens bones. Increased protein in the diet leads to greater levels of insulin-like growth factor-1, better calcium absorption, and more vitamin D. All these effects act to strengthen the bones.
And that's not all. A diet high in protein-rich foods, combined with weight training increases muscle mass and strength. This is especially important as clients age and naturally start to lose muscle mass. Having more muscle is associated with greater bone density.
Now that you explained to the naysayers that more protein is better, how much should you recommend?
Currently the FDA recommendation for a daily protein intake is 50 grams for both men and women. This is a very general recommendation and isn't accurate for highly active clients.
For people who work out, for athletes and trainers, more protein is necessary to build muscle and aid in recovery.
At this point, there aren't any studies showing that 2 grams of protein per kilogram of body weight is harmful - although there's still ongoing research in this area.
For clients who are moderately to extremely active, 2 to 3 grams of protein per kilogram of bodyweight is a good general guideline.
This means that for an athlete who weighs 175 pounds (this is about 80 kilograms), protein in the range of 160 to 240 grams per day is reasonable, much more than the FDA recommendation.
While helping a client figure out how much protein to eat, it is important to keep in mind that too much protein can be harmful for anyone with kidney disease or kidney damage. For clients with kidney damage, a recommended intake is about 0.6 grams per kilogram. 
Unfortunately, chronic kidney disease is known as a "silent disease." Symptoms are hard to detect, but you can get some simple tests done at your doctor's office to find out if you have any issues with your kidneys.
A serum creatinine level test or a urinary dipstick test for proteinuria will tell your doctor if you have any kidney damage and whether you need to be careful about protein intake. For clients with kidney damage, recommend a daily protein intake of about 0.6 grams per kilogram . 
As with any part of a client's healthy diet, recommend unprocessed, whole foods, even for their protein sources.
Animal proteins are excellent sources of protein. Generally, animal proteins are complete proteins, meaning they containing all the necessary amounts of the essential amino acids a body needs. Clients can choose from an array of options in this group: poultry, red meat, eggs, fish, milk and more.
For plant-based protein, encourage your clients to try foods such as quinoa, buckwheat, or hempseed. While plant-based proteins are often incomplete proteins—lacking the optimal amount of amino acids—combining multiple sources can create a complete protein. For example, beans and rice—each one has the amino acids the other one is missing.
Protein supplements like protein shakes and protein powders can serve as backup options. Supplements, such a protein powder, can be helpful when clients don't have time to cook or the ability to access whole-food protein sources. This is particularly helpful for highly active clients, such as bodybuilders, who require larger amounts of protein to maintain and build muscle but don't have the time to make additional meals.
Now you have the myth-busting facts and additional tips to go help your clients, friends, and family make better choices about protein—go forth and change some minds. For ways to work the best amounts of protein into clients diets, check out ISSA's Nutrition Coach program.
By becoming an ISSA Nutritionist, you'll learn the foundations of how food fuels the body, plus step by step methods for implementing a healthy eating plan into clients' lifestyles.
Juraschek, S.P., L.J. Appel, C.A.M> Anderson, and E.R. Miller III. Effect of a high-protein diet on kidney function in healthy adults: results from the OmniHeart trial. Am. J. Kidney Dis.61(4): 547-54, 2013.
Landau, D. and R. Rabkin. Effect of nutritional status and changes in protein intake on renal function. In: Nutritional Management of Renal Disease (Third Edition),Chap. 13, J.D. Kopple (Ed.) Academic Press, 2013, pp. 197-207.
Levey, A.S., S. Adler, A.W. Caggiula, B.K. England, T. Greene, L.G. Hunsicker, J.W. Kusek, N.L. Rogers, and P.E. Teschan. Effects of dietary protein on the progression of moderate renal disease in the modification of diet in renal disease study. J Am. Soc. Nephrol.7(12): 2616-26, 1996.
Levey, A.S., S. Adler, A.W. Caggiula, B.K. England, T. Greene, L.G. Hunsicker, J.W. Kusek, N.L. Rogers, and P.E. Teschan. Effects of dietary protein on the progression of advanced renal disease in the modification of diet in renal disease study. Am. J. Kidney Dis.27(5): 652-63, 1996.