Cutting through the protein hype.
Let's unpack the truths and misconceptions around protein intake.
On grocery store shelves, commercials, and all across social media, it’s everywhere: protein, protein, protein. As a nutritional scientist, I can’t help but cringe. “Protein” is one of those things that has become so massively overhyped in recent years and used to sell so much junk that is unhealthy for us. But, of course, it’s also a genuinely a really important nutrient and bad things can happen if you don’t get enough. The problem is that a lot of people just don’t quite understand how low “enough” actually is. But how should the average person know how much they actually need?
To help answer this question, I put the following article together to cut through the hype: what protein actually is and why we need it, how it’s become so overhyped in recent years, why that’s a problem, and what we can do about it.
This is Part 1 of my upcoming protein series; Part 2 will be a deep dive into alternative protein products coming out of the Food Technology space and Part 3 will try to answer the leading question of this series: what does the future taste like?
What is protein and why do we need it?
Of all the macronutrients we need to fuel our bodies—carbs, fats, and protein—protein is somewhat unusual. Fats and carbs are quite convenient forms of energy because the body can either use them straight away, or store to use them at a later time. But protein is different. During digestion, protein is broken down into small molecules called amino-acids. These amino-acids can be used right away or they are transformed into a storage medium called glycogen. But here’s the rub: glycogen cannot be turned back into amino-acids. What this means is that we need to be eating protein regularly to provide a steady stream of amino acids.
Amino acids from food are the building blocks of our body’s own human proteins. Protein is found in all kinds of food—meat, dairy, seafood, grains, legumes, fruits & vegetables—but in different amounts. Animal-based foods, like meat, are the most concentrated in protein, there are also plenty of plant-based sources of protein.
Although the body can produce some amino acids itself, we can only get other, so-called “essential” amino acids,from our diet. If we don’t, we’ll be in pretty bad shape. In order to make sure we stay healthy, our brain has ways of ensuring that we get the bare minimum of protein - which is around 5 to 14 percent of daily food and drink intake. If our protein intake makes up less than that, our brain triggers processes that make us ravenously hungry so that we increase our food intake—even if we have met our energy needs for the day. This is called protein leverage1 and it serves to protect us: if we don’t eat enough protein for a while, our body will get its amino acids from breaking down our muscles, and after some more time, protein deficiency sets in, which brings a whole host of nasty symptoms—ranging from joint swelling, brittle hair and nails, and less elastic skin to slower wound healing, mood swings and extreme fatigue, brittle hair and nails, skin losing its elasticity, wounds heal much more slowly, changes in mood and extreme fatigue.
While too little protein is bad, so is getting too much. It’s been documented that eating too much protein can strain our liver, kidneys and vascular systems. While the cut-off point isn’t exactly clear, experts today seem to agree that there is a sweet spot for protein consumption to keep us healthy, and that seems to be from around 0.8g of protein per kg of bodyweight, up to 2g of protein per kg of bodyweight2–5.*
Why is there a hype around protein?
In the developed world today, inadequate protein intake is almost non-existent (yes, even in strict vegans). But even so, we’re quite obsessed with protein. Some might say for good reason. Indeed, making sure we get optimal amounts of protein can help to build muscle and make us feel more full after a meal, points out Sandra Mikhail, Accredited Practising Dietitian and founder of Nutrition A-Z.
For already several decades, various diet gurus have been promoting protein as a magic nutrient that would keep you fuller for longer, and therefore allow you to lose weight and keep it off. The 20th century saw a boom in high-protein diets, with the food industry catering to people’s desire to lose weight, while keeping their muscle mass. This started with the Atkins diet, which uses the fullness-inducing effects of protein to help with eating less and losing weight6. There is some truth to that; ingesting protein causes specific hormones to be released in your gut that signal to the brain it’s time to stop eating6. That said, there are several other things beyond protein consumption that also help us feel full 7,8, although some evidence suggests that protein’s signal is stronger9. In general, this led to some diet “experts” recommending eating an abundance of protein-rich animal products. However, there are potential risks in eating too much protein, as we already discussed.
A renaissance of the high-protein craze came in the 21st century with the explosion of “ancestral” type diets, from paleo to carnivore, which are advertised as being high in animal protein (and in some cases, almost only consisting of meat)10. The pseudo-scientific argument goes that “eating meat made us human” and a high-meat diet is what we are “evolutionarily primed” to thrive on. While several studies have debunked this claim, it remains a popular excuse to indulge in a high-meat diet10–12.
Generally speaking, getting enough high-quality protein (i.e., all essential amino acids in a well-balanced diet) is not a problem in developed countries. As Sandra Mikhail puts it, “if you’re eating enough calories, you’re eating enough protein. We only see cases of too low protein intake in some clinical cases of eating disorders, where total calorie intake is inadequate.”
So what’s the problem?
Unfortunately, protein, and animal protein specifically, is a pretty expensive nutrient.
First, eating meat is quite costly for our health. Some popular protein sources, like red meat and processed meats, can increase the risk of cancer (and are considered to be Class 2A and Class 1 carcinogens, respectively13). The jury is still out about other forms of animal protein14, but some studies have shown that they may harm human health as well15, 16. Beyond the known carcinogenic effect of red and processed meat, we also know that high meat consumption is linked to poorer heart health. Studies have shown that meat-rich diets may lead to more atherosclerosis, heart attack and stroke.
On top of that, meat-heavy diets also often neglect some other nutrients that are important to our health; the Atkins diet, for instance, is pretty poor in fiber-rich foods like grains and starchy vegetables. Fiber is a type of carbohydrate, but humans can’t digest it. However, the trillions of gut microbes living in our guts thrive on it. In exchange for feeding them with fiber, our gut bacteria produces a wide variety of chemicals that are beneficial for our health18. Scientists have observed that those eating meat have less diverse and different microbes in their gut than people eating a plant-centric diet21,22. While we don’t exactly know what a healthy gut microbiome looks like, we do know that the more diverse the species of microbes we host, the better.
Secondly, making animal protein is expensive for our planet. Animal farming specifically is a major contributor to global warming and loss of biodiversity. Livestock farming and fish farming together make up 15% of global greenhouse-gas emissions19,20, although they only account for ⅓ of the global protein supply23. It’s also a very inefficient use of our crops, as it takes 9 kilocalories of plant-feed to create 1 kilocalorie of meat24. As Laura Sommer, an expert in food systems, puts it, “it takes a lot longer for meat to get into your stomach, so it needs more resources along the way.” Plants, on the other hand, “can grow and we can eat them directly from the field”.
On top of that, to plant crops for animal feed, massive areas of land are being cleared in the Amazon rainforest and other ecosystems that suck planet-warming carbon out of the air, jeopardizing our ability to mitigate global warming. 25–27. Tofu, a very popular plant-based protein in all sorts of dishes, on the other hand, doesn’t have this problem28. When thinking about sustainable sources of protein, Sommer points to two key factors to consider:
Firstly, how it was produced? Go for plant-based foods over animal-based products, and small local farms over factory farms.
Secondly, how much of it do you eat? Ideally, we shouldn’t be eating more than 300 grams per week of meat, according to the EAT-Lancet Commission on Food, Planet, and Health, an international scientific body tasked with establishing what composes a healthy diet within planetary boundaries29.
What are the solutions?
Considering the clear issues with overconsumption of meat, you might be wondering why we continue to eat so much when we know that plants can give us the protein we need. In the next article in the Future of Protein series, we will delve into the deep emotional and cultural ties we have with meat consumption, which might be one of the reasons we keep eating it despite the known downsides. Because we humans like to solve our problems using technology, we’ll also look at how emerging protein tech and food innovation may allow us to have it all: meat, health, and a thriving planet.
*Footnote:
Perhaps you are wondering why there is such a large range in what experts consider how much protein we can and should eat. In fact, there are many different variables that might affect how much daily protein is right for you. These include: your activity level, your biological sex, your muscle mass, whether or not you’re pregnant, your age, how well your gut can absorb protein, to name a few.
References:
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