But humans have been eating both plants and meat for thousands of years. In fact, many nutrients that are important for overall health can only be found in meat, fish and dairy products. As such, trying to obtain these nutrients when you're on a strictly plant-based diet can be very challenging, if not impossible.
Unless you take nutritional supplements, avoiding animal foods at all costs could lead to severe deficiencies in these seven important nutrients:
Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a key role in the development of red blood cells. Vitamin B12 is also known for supporting cognitive function.
Creatine is one of the most popular muscle-building supplements in the world. Studies show that short-term creatine supplementation can lead to greater gains in muscle mass and strength. It can also improve exercise performance. (Related: Performing aerobic exercises can improve overall endurance, even after a stroke.)
Creatine is not an essential nutrient since the liver can produce this organic acid. However, some studies have found that vegetarians tend to have lower levels of creatine in their muscles, where most of this substance is stored.
Creatine can be obtained from chicken, salmon, tuna, beef and venison.
Carnosine is strictly found in animal tissues. It plays a crucial role in regulating muscle function, boosting muscle recovery after a workout and improving exercise performance and endurance.
Carnosine is considered non-essential because the human body can produce it from two amino acids, namely histidine and beta-alanine. Nonetheless, recent studies have shown that vegetarians tend to have lower levels of carnosine in their muscles than meat eaters.
Vitamin D is a fat-soluble essential vitamin that appears in either one of two forms: ergocalciferol, or vitamin D2, and cholecalciferol, or vitamin D3.
Vitamin D3 is the more potent form of vitamin D since it can be readily absorbed by tissues. It can only be found in a few animal-based foods, such as fatty fish, egg yolks and cod liver oil.
Having high levels of absorbable vitamin D is crucial to maintaining strong bones and strengthening immune health for better protection against infection and disease.
DHA is one of three primary forms of heart-healthy omega-3 fatty acids. It is essential for healthy brain development and optimal cognitive function. DHA is typically found in fatty fish like salmon and tuna.
Heme iron is one of two types of dietary iron consumed by humans. As a component of hemoglobin -- the protein in red blood cells that carries oxygen to various organs -- heme iron can only be found in animal flesh, such as red meat, poultry and seafood. According to studies, the body absorbs heme iron better than non-heme iron from plant-based foods.
Taurine is a sulfur-containing amino acid known to support muscle function and bile salt formation. Taurine also helps strengthen the body's antioxidant defenses against oxidative stress, a known trigger of inflammation.
Taurine is found in pork, beef, chicken, fish, seafood and several dairy products. The body also produces very small amounts of taurine. Because of this, vegetarians have lower taurine levels than meat eaters.
There are many good reasons to go meat-free. But doing so could lead to severe deficiencies in some essential nutrients. To avoid the consequences of certain nutritional deficiencies, make sure to take the necessary supplements so you can meet your daily nutrient requirements while being on a vegan or vegetarian diet.