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How Much Protein Do I Really Need?

ISSA, International Sports Sciences Association, Certified Personal Trainer, Need, How Much Protein Do I Really Need?

Learn how to protect yourself AND your clients from the health risks of over-supplementation 

As a personal trainer, you already carry a TON of responsibility on your shoulders.

You're accountable for safely guiding your clients through the fitness and lifestyle protocols that will help them achieve the results they’re paying you good money for....

But what do you do, when despite your best efforts, clients continue to unknowingly sabotage their health and performance with an unstable and even dangerous diet...?

Worse - a diet they’ve been convinced by marketing hype IS the ideal one for them and their performance goals.

And finally, how do we as trainers arm ourselves with the facts needed to dismantle those myths and get our clients back on a path towards greater health and performance? 

The Hidden Dangers of Self-Supplementation

Left to their own devices, your clients will often (and dangerously) buy into the supplement marketing hype they’ve been pummeled with.

The siren cry is simply too tempting.

Who doesn’t want double the results in half the time just by guzzling down a few extra protein shakes or swallowing a handful of pills?

And on a certain level - we have to respect and even admire our clients’ determination to do “whatever it takes” to achieve their performance goals. After all, it’s that very same motivation that propelled them to take action and hire you as a trainer in the first place....

But if you look at the data, the outcome is bleak for amateur athletes and bodybuilders who take supplementation into their own hands without the proper guidance of an expert.

Look no further than the following 2015 case study, published by Gaurdia, Cavallaro and Cena. This study proved that excessive protein and vitamin/mineral supplementation may not only be unnecessary for bodybuilding and athletic gains, but lead to some serious health risks...

CASE STUDY: Excessive Protein Intake Puts Amateur Bodybuilder on the Sidelines

This case in question features a 33-year-old male bodybuilder weighing 189 pounds, with 20% body fat.

After years of intense training and a self-designed supplementation plan, the subject began experiencing severe gastrointestinal side effects including weakness, fatigue, stomach irritation and recurrent episodes of diarrhea. Symptoms got so severe that his compromised body actually prevented him from continuing his training program, with this result: he lost all the muscle gains he’d achieved during the previous six months of intense training.

How’s that for counterproductive?

The study noted that, during the previous 16 years, the subject’s daily caloric intake hovered around 3,000 calories with an average daily protein intake of 2.3 grams per kilogram of body weight (g/kg/day). He was also consuming 30 grams of whey protein in addition to his macronutrient serving of protein, while his fiber intake was capped at around 19 grams per day.

Here’s what that all looks like:ISSA, International Sports Sciences Association, Certified Personal Trainer, Need, How Much Protein Do I Really Need?

 Notice something off-putting about that? 

I’ll wait while you digest it. (pun intended)

See it yet?

His supplement intake WAS NOT very different from the average amateur athlete’s. Perhaps the most alarming thing about the statline is that it’s not so different from what many amateur athletes and bodybuilders typically consume. Maybe you, as a trainer and athlete, still consume protein and calories at around the same clip... 

What’s scary is how this over-consumption has become so normalized within the athletic / bodybuilding culture.

Compare it to the international dietary guidelines, which states that a balanced diet consists of:

  • A macronutrient ratio breakdown of 55% carbs, 30% fats and 15% protein.

  • Protein intake of 0.71 to 0.9g/kg/day for a moderate-level athlete, sliding up to 1.2 to 1.7 g/kg/day for high intensity or resistance athletes training 3 to 5 days a week.
  • Fiber intake between 20 to 30 grams per day to maintain proper gastrointestinal activity.

If You’ve Already Started Consuming Too Much Protein, Is Recovery Possible?

With his gains depleted and gastrointestinal health continuing to suffer, the subject of the study was put on a strict nutritional protocol designed to reverse the damage of his self-imposed diet. The carefully-constructed protocol took his resting energy expenditure and level of physical activity into full consideration.

Here’s what his diet looked like:

ISSA, International Sports Sciences Association, Certified Personal Trainer, Need, How Much Protein Do I Really Need?

The subject was also advised against any additional protein consumption and multivitamin / mineral supplementation for a period of 30 days. The only exception? A high-quality probiotic and Vitamin E supplement to help accelerate the recovery of his gastrointestinal system.

So what happened?

The proof is in the supplement-free pudding...

Following this strict protocol, the subject’s symptoms quickly subsided, allowing him to return to action with a healthier, more efficient and less-taxed gastrointestinal system.

The researchers also concluded that, in addition to excess protein, excess Vitamin A, Niacin, Zinc and Selenium also may have played a role in the subject’s gastrointestinal symptoms (Guardia et al., 2015).

So what exactly was it about this cocktail that led to such deleterious effects?

It’s suggested that high protein consumption may induce gastrointestinal discomfort and impair water absorption in the intestinal tract.

When this vitamin and mineral overconsumption is combined with excessive protein intake, the adverse side effects of gastrointestinal discomfort may be amplified even further as was the case in this study.

5 Ways We Can Put “Protein Supplementation Awareness” Into Practice For Our Clients

This is the low-pain path to a more balanced diet for your clients:

  1. Any nutrition advice you provide should take into consideration your client’s body fat percentage, daily activity level, and appropriate caloric ratio specific to their daily activity needs for protein, carbohydrates, and fat.

    Remember, resistance athletes require no more than 1.2 - 1.7 g of protein per kg of weight for muscle repair to go along with 8-10 kg/day of carbs.

  2. Insist that your clients seek proper advice from a nutritionist or physician before creating self-made diets.

  3. Warn them of the risks of over-supplementation - reminding them that in the medium to long-term they actually sabotage health and performance. Advise them to be cautious around marketing hype.

  4. As much as possible, encourage clients to receive their vitamins and mineral intake from whole foods instead of supplements.

  5. Suggest they keep a daily food journal to discover and track their eating habits in relation to their goals.

So…. how much protein does a person need?

Probably not as much as you think.

More is not always better. And those who pursue self-made diets should never overestimate the role of macronutrient intake while underestimating the potential side effects of micronutrient over-supplementation.

Christina Klein


Guardia, Lucio Della. Cavallaro, Mauricio. Cena, Hellas. “The risks of self-made diets: the case of an amateur bodybuilder.” Journal of the International Society of Sports Nutrition (2015) 12:16. Web. 01 April. 2015.

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