bite my words

Dispelling nutrition myths, ranting, and occasionally, raving


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More on protein

I don’t know if it’s just me, but I have been seeing a bunch of infographics such as these lately:

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While the second one’s much better than the first (credit: Avery Muether Illustrations), it includes fairly accurate protein quantities (and some of these foods are reasonably high sources of protein), I still wanted to comment on them. I went through the foods included in the first infographic and looked up the protein in a serving of each. Here they are:

spirulina (1 tbsp dried) – 4g

goji berries (2 oz dried) – 8g

chia seeds (1 oz) – 4.4g

spinach (1 cup raw) – 0.9g

hemp seeds (2 tbsp) – 10g

barley grass (6g dried) – 1.5g

brazil nuts (1 oz) – 4g

broccoli (1 cup raw) – 3g

(bean) sprouts (1 oz) – 0.8g

figs (1 oz dried) – 0.9g

avocado (1 oz) – 3g

maca (1 tbsp powder) – 1g

kale (1 cup raw) – 2g

romaine lettuce (1 cup shredded) – 0.6g

For the most part, I wasn’t overwhelmed by the amount of protein in these foods. Considering that a single serving of protein is considered to be approximately 6-7g. Even if you consumed all of these foods in a day you would be consuming only 44.1g of protein in total. This is quite close to the needs for many women. Protein needs are generally 0.8g per kg of body weight. However, more protein may be needed in some cases such as for athletes, pregnancy, wound healing, childhood, elderly, etc. Even so, most of us handily exceed the daily requirements for protein.

There is something else beyond total protein to consider, however. We also need to look at protein quality. High quality proteins are those that contain ample amounts of all nine essential amino acids. I’m sure you already know this but just as a refresher… Amino acids are the building blocks of proteins. There are 20 (or 21 if you count cystine) amino acids, 9 of which are considered essential because our bodies cannot synthesize them and must, therefore, obtain them from food. Animal proteins (with the exception of gelatin) are considered to be high-quality as they contain all of the essential amino acids in ample quantities. Many plant proteins are considered to be low-quality as they are either low in, or lack, one or more of the essential amino acids. While it’s absolutely possible to obtain all of the amino acids we need from plant proteins it also takes more careful consideration than proteins obtained from animal sources. This is why we talk about complementary proteins. These are plant protein sources that, when combined, yield adequate amounts of all 9 amino acids. A few examples are: hummus and pita, rice and beans, veggies and polenta. Just to be clear, the complementary proteins needn’t be consumed together at the same meal (although they certainly can be) as long as they’re consumed throughout the day.

Generally speaking, aside from foods such as beans, nuts, and seeds, plant proteins are lower in total protein (not just essential amino acids) than animal proteins. Just a few examples: 3 oz of canned tuna has 21.6g of protein, 3 oz of chicken breast has 21.3 g, Greek yoghurt can contain up to 15-18g per serving.

Yes, it is possible to consume adequate protein without consuming animal products. It’s likely preferable if we do favour plant sources of protein over animal sources. However, it’s not as simple as those infographics make it seem. Most foods contain some quantity of protein. That second infographic especially irks me. Suggesting that romaine lettuce and figs are good sources of protein is ludicrous.


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Forget sugar. Protein is the new smoking.

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A recent study in Cell Metabolism prompted numerous headlines proclaiming that protein (specifically animal protein) may be just as bad as smoking for your health. Before we jump on the anti-protein bandwagon let’s take a look at the actual study.

The researchers used the results from the NHANES (National Health and Nutrition Examination Survey) in combination with mouse and cellular studies. There were over 6, 000 participants in the NHANES which is quite a robust sample. Right off the bat it makes me suspicious that the researchers would also need to incorporate mouse studies. We also know that using nutrition data from self-reported surveys is far from ideal: people tend to under-report food intake. In this case the researchers used 24-hour recall. The pro to this is that it’s one of the more accurate methods for collecting dietary data. The major con to this is that the researchers are assuming that food/nutrient intake from one day is representative of intake every day. That’s a huge assumption. I know that I might eat animal protein at a couple of meals on one day while eating none on another. That would mean I could fall into either the low or high protein intake group depending on the day data collection was undertaken. We also know that mice are not humans (duh) and that research conducted using mice may not be translatable to a human population. Okay, not enthusiastic about the methods, but let’s take a look at the results.

The researchers found no association between all cause, cardiovascular disease, nor cancer mortality and protein intake in all participants over the age of 50. They did find an increase in mortality in participants in the high protein (20% or more of total daily calories from protein) group who had diabetes. Naturally, they could not say with certainty if the high protein intake was the cause of diabetes mortality. However, when they broke the results down further (splitting the group into those aged 50-65 and 66 and up), they found a relationship between high protein intake and all-cause and cancer mortality in the 50-65 age group. They reached the conclusion that animal-based proteins were the cause of this increased mortality because when they controlled for animal protein the “association between total protein and all-cause or cancer mortality was eliminated or significantly reduced”. This was not seen when plant-based protein was controlled for. Interestingly, the opposite was found in the over 66 years age group (i.e. higher protein intakes reduced risk of mortality from cancer or cardiovascular disease).

It appears that the researchers didn’t control for all confounding variables when they were examining mortality and protein intake. There is no mention of controlling for physical fitness, economic status, or employment status. These are important factors to consider when investigating the effect of diet on mortality.

So, what can we conclude from this study? High animal protein intake may increase your risk of mortality if you’re between the ages of 50-65. After that, it may have a protective effect. This suggests that protein plays different roles at different ages and also means that we cannot extrapolate the results to those under the age of 50. We also can’t be certain that the results are accurate due to the limits when using dietary recall data as well as the lack of control for certain potential confounding variables. There may be some benefits to including more plant-based sources of protein in our diets; however, it may be premature for us all to go vegan.

After writing this post, I read the review of this study on Examine.com in which they address the mouse study. They also make some really good points about the protein-human study, including the fact that there’s no differentiation between protein sources beyond separating animal and plant proteins (can we really assume roast chicken is the same as beef jerky?). I highly recommend taking a look at their review.


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Grocery Store Lessons: Protein powder

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As with all foods/supplements, all protein powders are not created equal. Protein powder isn’t something that I consume much of. I find it’s often gritty and overly sweet and I’m confident that I can get adequate protein from consuming whole foods. However, for the sake of product knowledge, I do occasionally try a protein shake as part of my breakfast.

I always look at the protein content of each protein powder. As an aside, most tend to be about 24 grams per serving, although, some, such as hemp protein powder, can be considerably lower (8-15 g). Something I never considered looking at was the sodium content until one day I just happened to notice it on the package shown on the above left. I was shocked that a serving of protein powder would contain half a day’s worth of sodium. It is a “sport” protein so maybe that’s why; to replace electrolytes lost during an exceptionally sweaty workout. Still, I’m sure that most people wouldn’t expect to be getting so much sodium from a protein shake and I imagine that there are others out there like me who never even thought about looking at this information. I started looking at the nutrition information labels on other protein powders in the store. Most were similar to the much more reasonable 130 grams seen in the whey protein powder (pictured above right).

If you do consume protein powder regularly you might want to check the label to ensure that you’re not getting more sodium than you bargained for.


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Grocery store lessons: Greek yoghurt

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I’ve extolled the virtues of Greek yoghurt in the past. It’s a pretty great source of protein at up to 18 grams in 3/4 of a cup! Of course, once something gets popular you know that the knock-offs aren’t far behind. I think that nearly every brand of yoghurt now has their own line of Greeks on the market. Unfortunately, many of them aren’t actually Greek yoghurt.

True Greek yoghurt is made by straining regular yoghurt so that you’re left with a thick creamy yoghurt. This separation of the whey (that’s the watery stuff that’s strained out) leaves the Greek yoghurt rich in protein but also removes some of the calcium… It can’t all be good, right? While a serving of plain yoghurt has about 30% of your daily recommended calcium, a serving of Greek yoghurt only has about 15% of your daily recommended calcium. But I digress…

What’s wrong with the “knock-off” Greek yoghurts? Well, they’re not strained. Instead of just containing milk and bacterial culture they add thickeners like carrageenan, corn starch and pectin to achieve a thick Greek-style creaminess. They also add milk protein to bump up the protein content but from the ones I’ve seen that still only puts them at 8 grams of protein per serving. That’s actually less protein than you’ll find in many traditional plain yoghurts. Most of them also tend to be targeted at the “dieting” community so they’re sweetened with artificial sweeteners. And lest you think “at least I’m still getting the calcium I would from traditional yoghurt” you’re probably only getting about 10% of the Daily Value.

If protein and a thick creamy yoghurt are what you’re looking for make sure to check the ingredient panel as well as the Nutrition Facts Panel to ensure you’re getting exactly what you bargained for. When it comes to yoghurt ingredients, less is definitely more.

*The photo above shows the Nutrition Facts for a traditional Greek yoghurt and a “knock-off” Greek. Can you tell which is which?


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Grocery store lessons: Honey Bunches of Oats Greek Yogurt Honey Crunch

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I’ve noticed a proliferation of Greek yoghurt “product” on grocery store shelves recently. Capitalizing on the popularity of Greek yoghurt, the food industry is now making “Greek yoghurt” cereals and granola bars. But do these products provide you with the same benefits (i.e. protein and probiotics) as eating actual Greek yogurt does?

One of these products is Honey Bunches of Oats Greek Yogurt Honey Crunch. Essentially, this is a flake-type cereal with a smidgen of yoghurt flavouring. “Greek yogurt powder” is the 20th ingredient; not exactly prominent. It’s also important to note that it’s a powder. Even if this “yogurt” still contained any live probiotics (which is highly unlikely) the miniscule amount included in this product is not enough to provide you with any of the health benefits you would obtain from eating actual Greek yoghurt. The same goes for protein. There is only four grams of protein in a 3/4 cup serving of this cereal. In comparison to plain Greek yoghurt which can have as much as 18 grams of protein per serving, and even flavoured Greek yoghurt which generally has 8 grams of protein, this is not a whole lot of protein. To put this in perspective, Shredded Wheat (which consists solely of wheat) contains six grams of protein per serving.

Aside from the yoghurt factor, looking at the overall nutrition profile of the cereal, it’s still not a great choice. The second ingredient is sugar. Keeping aware that sugar is also included in other forms and ingredients further down the ingredient list, it may actually be the most abundant ingredient in this cereal. Honey Bunches of Oats Greek Yogurt Honey Crunch boasts that it’s a “source of fibre”. Um… 3 grams of fibre in a cereal is nothing to boast about.

My advice: don’t fall for these Greek yoghurt products. If you want to obtain the nutritional benefits of Greek yoghurt, eat actual Greek yoghurt.