Among the three macronutrients – protein, fat, and carbohydrates – protein is probably the least disparaged. While carbs and fat have shouldered most of the blame (generally unfairly), protein has maintained its place at the head table of “good” nutrients.
Although the actual landscape of nutrition is far more complicated than that, protein is the most essential of those three macronutrients and getting enough protein is indeed important. That being said, I do still get many questions from clients trying to parse out which protein-rich foods are best.
It’s important to know that most people don’t have a problem getting enough protein. Most do fine with 60-80 grams of protein per day, perhaps a little less or more depending on activity levels. For perspective, the average American male gets 100-105 grams of protein per day, while the average female comes in around 70 grams per day.
If the protein question is regarding quality rather than quantity, it’s a longer conversation. How can we measure the quality of protein? There are a few ways.
One strategy is to look at amino acids. Amino acids are the building blocks of proteins, arranged in different patterns to form unique proteins similarly to how the letters of the alphabet can be reorganized to form different words. There are around 20 types of amino acids in the proteins that we consume, and nine of them are considered “essential” – if we don’t eat them, there will be negative consequences for our body.
A protein source’s “biological value” is, in part, how well that food’s amino acid profile matches up with the array of amino acids required in the human body. Here are a few examples of how various foods score on biological value (a higher number is more “biologically valuable”):
Whey protein: 104
Whole egg: 100
Cow’s milk: 91
Generally speaking, animal proteins score higher than plant proteins in this chart. This makes sense, as most plant proteins are not “complete,” meaning they don’t contain all of the essential amino acids referenced above.
This means whey protein is the best protein, right? Based on biological value, sure. Of course, nutrition is never that simple.
An additional consideration for protein quality is the diversity of nutrients that come along with the protein source. With whey protein in isolation, there’s not much that comes with it. Plant proteins, however, rate really well in this area. Foods like beans, lentils, nuts, seeds, and whole grains offer not only protein but fiber and numerous essential vitamins and minerals. Most of us don’t eat enough whole plant foods, so these nutrients are especially important.
Additionally, combining plant foods together improves the biological value of their protein. Beans on their own score around 50, but combining them with some corn or rice can push that number up around 100. This is why protein variety is especially important for those following a vegan diet.
What about red meat? Beef is very rich in protein, offers lots of highly-absorbable iron, and vitamin B12. At the same time, it carries more saturated fat than most other protein foods and consuming large amounts of red meat on a daily basis is correlated with increased risk of colorectal cancer.
There are pros and cons of all protein foods, but the true answer here is balance. Featuring plant-based proteins in meals on a regular basis is a good idea for most people, and fish, eggs, and dairy are excellent complements to ensure adequate protein intake. Red and processed meats should be consumed less frequently, but you don’t have to eliminate them completely to reduce your health risks. If you choose to eliminate meat altogether for ethical or environmental reasons, make sure you’re eating a diverse set of protein-rich plant foods to cover your bases nutritionally.