Protein Deficiency on a Plant Based Diet?

A common misconception about the plant based/vegan diet is that it can lead to protein deficiency.

"But where do you get your protein??"

If you've ever heard that from someone who just found out you don't eat animal products, here's a good scholarly answer ;)

While protein needs may vary depending on your fitness goals, you don't actually need to consume animal proteins to get all the protein your body needs. A varied whole food plant based vegan diet is sufficient in protein. That is, as long as you are eating enough calories.

Amino acids are the building blocks of protein (is this ringing any biology class bells?). The protein in our food and body are composed of 20 amino acids - 11 of these we can create in our own bodies using nitrogen, the other 9 need to be consumed from food since we cannot make them.

An essential amino acid is one our bodies need but cannot make on its own, therefore we must consume and absorb them through our food. The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Non-essential amino acids are ones our bodies need, but make enough on their own. We don't need worry about consuming these in order to fulfill our bodies need for them. The 11 non-essential amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutemic acid, glutamine, glycine, proline, serine, and tyrosine.

All plant proteins have all the essential amino acids. Plant proteins are just as good and as complete as animal proteins. Although not all plant proteins contain the same amount and proportions of each amino acid, they are perfectly adequate in providing what our bodies need.

Many people believe we need meat for protein even though the idea of plant proteins being incomplete and inferior to animal proteins has been dismissed by the nutrition community decades ago. The American Heart Association has officially stated on their website that the protein found in plants is perfectly adequate and supplies all of the essential and non essential amino acids, and there is no need to combine protein sources in order to meet the needs of our bodies. (I had a link to the specific webpage, but it has since been removed, and I'm unable to find it again.)

As long as you're eating enough calories to meet your energy needs, you will not be protein deficient. In fact, it is nearly impossible to design a diet with a variety of whole plant foods that is sufficient in calories but deficient in protein, based on the way our bodies store and recycle protein for its specific needs. Our skeletal muscles keep a sizable storehouse in the intracellular spaces of free amino acids to regulate our protein levels. Every day, about 90g of protein is dumped into our intestines to be broken down and reassembled to whatever proportion of amino acids we need. We do not need to be concerned with the amount of protein we are consuming, or if we are getting all of the essential amino acids. Our bodies were designed to prevent this type of deficiency by storing and recombining the amino acids to be used as our body requires.

So don't worry about if you're getting enough protein, just eat enough calories with a variety of plant foods including whole grains, fruits, veggies, beans and legumes, nuts and seeds, leafy greens, etc. and you will have what your body needs.