Protein - can you have too much of a good thing?
A story made headlines recently about an Australian woman who tragically died after consuming a very high protein diet in preparation for a bodybuilding competition, due to an undiagnosed metabolic disorder (full story here). According to results from the 2015 Canadian Community Health Survey, almost 50% of Canadians are using nutritional supplements and the daily percentage of energy intake from protein has increased for both children/teenagers and adults. Between these stories and several conversations we’ve had, we were inspired to write a blog post about protein - and if you actually can have too much of a good thing.
First, let’s get back to basics… what exactly is protein? What does it do? What are some food sources of protein?
Essentially, protein is broken down by the body into amino acids which are then used:
As structural building blocks (muscles, bones, hair, skin, nails, etc.)
To carry oxygen around the body
For tissue repair
To fight infections
As part of enzymes and hormones
As a source of energy
It is important to note that, unlike other macronutrients (carbohydrates and fat), the body does not store protein and therefore we need to consume adequate protein from food. If our diet is inadequate in protein, the body may turn to our muscles as a protein source which results in muscle breakdown and loss.
So what are some food sources of protein? Protein can be found in both plant and animal-based food, here are some examples:
Meat and poultry
75 g or ½ cup portion has ~21 g of protein
Fish and seafood
75 g or ½ cup portion has ~21 g of protein
2 large eggs have ~12 g of protein
Nuts and seeds (and their butters)
¼ cup of nuts or seeds has ~3-8 g of protein
2 tbsp of nut or seed butter has ~4 g of protein
Legumes (e.g. beans, peas, lentils)
¾ cup of dried legumes has ~12 g of protein
¾ cup of hummus has ~9 g of protein
Tofu, soy milk, and other soy products
150 g or ¾ cup of firm tofu has ~12 g of protein
1 cup of fortified soy milk has ~7-8 g of protein
Dairy products (e.g. milk, cheese, yogurt)
50 g of cheese has ~ 12 g of protein
1 cup of cow’s milk has ~9 g of protein
¾ cup of yogurt has ~7 g of protein (the same size portion of Greek yogurt has ~14 g of protein)
Okay, so now that we’ve got the basics, how much protein do we actually need?
The Institute of Medicine (IOM)’s Recommended Dietary Allowance for protein for the average, healthy adult is 0.8 grams per kilogram body weight. Many websites are promoting 0.8 grams per pound of body weight, however this calculates out to 1.76 g/kg which is too high and not supported by current evidence for average, healthy adults. Please note that children, pregnant and breastfeeding women, some athletes, and individuals with certain medical conditions have different protein requirements. If you fit into one of these categories, make an appointment with Alex or Stephanie today to discuss your individual protein needs.
an individual weighing 80 kg (176 lbs) needs around 64 g* protein per day
an individual weighing 65 kg (143 lbs) needs around 52 g* protein per day *you can compare these values to the food examples above
The IOM states that 10-35% of an average, healthy adult’s daily calories should come from protein. The easiest way to ensure you are getting enough protein is to include a source of protein at each meal and most snacks, or by following Canada’s Food Guide (the latest version is soon to be released).
Protein supplements or powders, such as whey protein, can be helpful for individuals who have a higher protein requirement or as an easy, convenient source of on-the-go protein. However, it is important to note that supplements are often lacking in other nutrients.
Focusing on whole food sources of protein (see examples above) ensures that you are not only meeting your protein requirements, but also consuming adequate amounts of other nutrients. For example, whey protein powder will add protein to your diet but not much of anything else - whereas a glass of milk is a source of protein as well as a source of carbohydrate, fat, calcium, vitamin D, and vitamin B12. It is also important to note that it can also be easy to “overdo it” with supplements like protein powders, resulting in excessive protein consumption.
Tips from your dietitians:
Eat a varied, balanced diet which includes food from all food groups
Include a source of protein at each meal and most snacks
Focus on whole foods first, before adding in supplements or powders
Choose plant-based proteins more often than animal-based ones
Oftentimes people think that if some is good, more must be better. However, current evidence shows that there are no benefits of protein intakes higher than 0.8 g/kg or10-35% of total calories for the average, healthy adult.
So here’s the million dollar question: are there any risks associated with high protein intake? The answer is that too much of anything can be risky.
A diet which is too high in protein may lack other nutrient-dense foods such as vegetables, fruit, whole grains, and healthy fats. Under consuming other food groups may increase your risk for nutrient deficiencies, such as fibre and calcium.
Remember, protein has calories! Excessive protein intake can add up to excessive calorie intake which may attribute to weight gain and an increase in adipose tissue (fat).
Lastly, for individuals with certain medical conditions, high protein diets can be dangerous, or even fatal - as was the case with the Australian woman in the story we first mentioned.
While there have been some concerns that high protein diets may result in bone density loss, increased risk of kidney stones, and increased incidence of developing kidney disease; the current evidence is showing that these connections may not be as clear as we once thought. More research is definitely needed to investigate the long-term health effects of high protein diets and/or excessive protein supplementation.
It is also important to note that low-protein foods such as vegetables, fruit, whole grains, and healthy fats are essential to reducing risk of chronic diseases such as cardiovascular disease, diabetes, and cancer.
At the end of the day, if a high protein diet confers no health benefit to the average adult… why risk it? Protein is an essential nutrient for life - but so are carbohydrates and fat. Instead of singling out protein, we should be focusing on a healthy, balanced diet that includes whole foods from a variety of food groups to meet our nutritional needs, maintain a healthy body weight, reduce risk of chronic diseases, and create sustainable, long-term healthy eating habits. Always remember that supplementation (of anything) is not benign and can be risky!
Alex and Stephanie are here to answer all your nutrition questions - including any questions you may have about protein and supplementation. Click here to book your appointment with us today!