Vegetarian Nutrition

As long as a vegetarian diet consists of primarily, ya know, vegetables, then it's just about the healthiest diet possible. Harmful and useless saturated fats are low or nonexistent and vegetables are high in vitamins and minerals. Fish eaters might have an edge in the health race, even on vegans who cut out all animal products. But generally, just about anyone who can cut meat out of their diet, will likely notice real results, whether weight loss or vitality. However, there are some areas a vegetarian might want to watch out for.

Balanced protein diet

Let's address protein straight away. Rumors about protein deficiency are absurd. The typical moderately active human requires 35 kcal (Calories) and 0.8 g of protein per kilogram of body weight per day. In order to obtain sufficient protein without overeating, we need to consume at least 0.023 grams of protein per kcal (0.8/35). Let's take broccoli. 100g of broccoli has 2.82 g of protein and 34 kcal or 0.083 g/kcal. So broccoli has 3.6 times as much protein per kcal as required. Lettuce has 4.5 times as needed. Beans have over fives times as required. Even bell peppers, notoriously low in protein, contain 0.043 grams of protein per kcal, that's still almost twice the required amount.

Fruit, it should be noted, are typically low in protein. They may be high in fiber and other vitamins, but fruits are generally poor protein sources. Now let's look at an egg, often considered the ideal food, containing all the nutrients a baby chick needs to grow, including the chick herself. A typical egg contains 12.6 g of protein and 155 kcal. Let's do the math: 0.081 g/kcal. An egg has less than but almost as much protein per calorie as broccoli. Likewise, beef and beans are comparable to each other with about five times as much total protein per calorie as needed.

Essential Amino Acids

It is true that an egg, particularly the egg white, is loaded with various amino acids. Very few single foods can compete with eggs on amino acid variety. However our bodies create most types of amino acids from other proteins. There are only nine essential amino acids, that is amino acids that our bodies can not create. Many vegetable sources contain them all: soy, quinoa, hemp, amaranth, buckwheat, and funky stuff from the sea. If those sound exotic, rest assured a balanced diet contains all the protein you need, that's why it's called a balanced diet. Rice and beans, chips and salsa, beans and grain, hummus and pita, it's not hard. The exact suggested intake for each amino acid has changed over the years, but when last I checked, beef was not a complete protein source either. Whether carnivore or herbivore, we should all eat a wide range of foods to ensure optimal health.

So what should vegetarians watch out for? While a purely plant-based diet is quite high in vitamins and minerals, and low in saturated fats, it may be low in some essential nutrients. Namely, vitamins B12 and D, calcium, iron, zinc, vitamins A, and B2, a balance of omega 3 and 6 fatty acids, and often iodine.

Vitamin B12

Vitamin B12 is only synthesized by bacteria and is thus found in contaminated foods and soil; It can not be obtained from plant food. B12 is incredibly important as it is required for cell replication. B12 deficiency can lead to permanent neurological problems and deficiency can take years to become noticed though the damage may already have occurred. If not consuming any animal product, such as cheese or eggs, then the only proven bio-available source of B12 is supplement. The recommended daily intake of Vitamin B12 is 1-3 μg. That's incredibly tiny, though luckily our tolerance levels are incredibly high. Vitamin B12 is considered safe and non-toxic and B12 dietary supplements are often hundreds or thousands of times greater than we need. I'm not sure why, because our bodies can only absorb a bit at a time. Regardless, it is recommended to take B12 supplements daily or at least multiple times weekly. Don't mess around with this one on philosophical or hokus pokus beliefs. There's a lot of nonsense about natural sources, some new algae discoveries, or whatnot. Don't risk it. Some B12 analogues look like B12, test like B12, but are useless in our body.

Vitamin D

Vitamin D, the sunshine vitamin is not technically a vitamin, as our bodies can produce it with sufficient sun exposure. However, I live at high latitudes and do not get sufficient vitamin D in the winter. Furthermore, it is not clear how much our bodies produce, nor how much is required. We know that it is important for our bones. Few foods are naturally rich in Vitamin D. However, it is found in mushrooms, fish oil, fortified foods, and is produced in skin exposed to sunlight. If you live in a sunny land and are outside, vitamin D may not be a concern for you.

Minerals: Iron, Zinc and Calcium

Per gram, vegetables can not compete with meat as far as iron and zinc density. However, per calorie, some vegetables are superior iron sources. Fruits contain a lot of iron per calorie, but most of their weight is water. Dried fruits are thus excellent sources of iron. Excellent sources of iron and zinc include dark leafy greens, nuts, starchy veggies like potatoes and beans, soya in particular, mushrooms, and many grains. Also note that Vitamin C helps the body absorb iron. Many good sources of iron are also rich in calcium, such as broccoli and other dark leafy greens.

Essential fatty acids, omega 3

You've probably heard much of omega-3. It is not a specifically vegetarian concern, it's everyone's concern. In fact, after fish, the best sources of essential fatty acids come from vegetarian foods, seeds, sea plants and algae in particular. Omega-3 and omega-6 must be obtained from our food as our bodies can not generate it ourselves. From these two, other fatty acids are created, but there's a trick. Omega-3 and omega-6 compete with each other. If there is too much of one then it steals resources from the other and the other fatty acid can not perform its job. In the typical modern diet, whether vegetarian or carnivore, it is omega-3 that is loosing the battle. Flax seed and certain algae have an abundance of omega-3 over omega-6.

Vitamin A

Vitamin A is an important nutrient that is not found in abundance from many foods. However it is contained in high doses in orange veggies such as carrots and sweet potatoes.

Vitamin B2, aka Riboflavin

Vitamin B2 is also fairly rare in our food. However, B2 is abundant in yeast and nuts and to a lesser extent green leafy veggies, beans and whole grain.

Sources:
http://www.bloodindex.net/dietary_intakes_source.php
http://www.dnaindia.com/report.asp?newsid=1132188
http://www.cairodining.com/ShowPage.aspx?PageID=115
http://www.vegsoc.org/info/iron.html
http://www.vrg.org/nutrition/2009_ADA_position_paper.pdf
http://en.wikipedia.org/wiki/Asparagus
http://en.wikipedia.org/wiki/Banana
http://en.wikipedia.org/wiki/Broccoli#Nutrition
http://en.wikipedia.org/wiki/Essential_fatty_acid
http://en.wikipedia.org/wiki/Lentil
http://en.wikipedia.org/wiki/Riboflavin
http://en.wikipedia.org/wiki/Vitamin_A
http://en.wikipedia.org/wiki/Vitamin_D