The one thing that animal products have over a pure plant-based diet is that meat, poultry, fish, eggs and dairy products contain complete proteins. A complete protein is a protein that contains all of the essential amino acids (of which our body manufactures 10, and 10 we need to obtain from our diets ON A DAILY BASIS). Failure to obtain enough of even 1 of the 10 essential amino acids (the ones that we cannot make), results in degradation of the body's proteins, namely muscle, to obtain the one amino acid that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use so they must be in the food we eat every day for us to benefit from them.
Amino Acids Manufactured by our Body include: alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well.
Essential Amino Acids (that is, the amino acids required from our diets include: arginine (required for the young, but not for adults), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Only eggs, meat, milk and fish contain ALL of the essential amino acids.
The good news is if your vegetarian diet includes eggs and dairy products, you're definately able to get the proteins that you require. If however, you are on a strictly vegan diet, you can still get complete proteins from non-animal sources such as soybeans, spirulina, hemp seeds, amaranth, buckwheat, and quinoa. Another way that vegans and vegetarians can make sure they get all the proteins they require is through pairing foods together to make complete proteins. For example: Beans paired with nuts, whole grains or seeds will result in a complete protein. As long as these are consumed through the course of a day, your body will still recognise and utilise all the amino acids effectively. Old school thought used to insist that vegetarians consumed "complementary foods" at a meal, but studies have since shown that we have an amino acid pool where we cycle amino acids in the bloodstream and can store them. As long as you have a variety of grains, vegetables and nuts every day, the body will have the resources it needs to build healthy protein.
Another important point for vegetarians / vegans is that they often digest their foods more quickly than non vegetarians, meaning they need to eat more often to compensate for the higher energy needs of building muscle (and therefore losing fat) off their bodies. Remember, muscle takes up 30% of the space of fat, that's why we want it on our body! So where generally I advise five small meals a day, with vegetarians there is a possibility that the number of small meals a day could increase from five to say seven, or upwards!
As a personal trainer I still recommend meat consumption, for a number of reasons: caloric efficiency, blood sugar management being two of the main ones. It takes more calories to get adequate amounts of protein on a vegetarian diet. Living on beans and tofu increases the amounts of carbohydrates in ones diet significantly.
The main pitfall that most vegans / vegetarians fall into is that of consuming too many natural (that is, "healthy") fats when they are seeking to lose fat, gain muscle and become lean and fit-looking. For example, almond butter is loaded with fat, which means it's very caloric dense and harder to burn off. Fat is not particularly bad, in fact, we need healthy fats, but if you are trying to lose weight, hundreds of excess calories can add up if you are not aware of the amounts of fats, proteins and carbohydrates in your foods.
Below I have listed a number of protein sources (Animal and Vegan) and their percentages of carbohydrate / protein / fat per 100g serve. Personally I like to work in 100g serves as it is easier to round it to a percentage, and let's face it, most of us are much better at understanding something using percentages. I have prepared this table in order of protein content on some commonly used foods by non-vegetarians and and some vegan/vegetarian foods and supplements. I have highlighted those products with more than 10% fat, as these would be the products you would be looking to minimise in order to lose fat off your body.
| Type of protein | % protein | % carbohydrate | % sugars (including natural sugars) | % fat (including healthy fats) |
| Hemp protein powder | 49 | 1 | 0 | 2 |
| Nori / Sea vegetables | 42 | 42 | 0 | 0 |
| Lentils, red | 27 | 9 | 2 | 2 |
| Beef mince | 26 | 0 | 0 | 9 |
| Tuna, canned in water | 26 | 0 | 0 | 2 |
| Peanut Butter | 25 | 2 | 9 | 25 |
| Peanuts | 24 | 2 | 4 | 22 |
| Farmed salmon | 22 | 0 | 0 | 34 |
| Almonds | 21 | 2 | 4 | 22 |
| Seitan | 21 | 1 | 0 | 2 |
| Chicken breasts | 21 | 0 | 0 | 4 |
| Grass-fed meat | 20 | 0 | 0 | 15 |
| Tempeh | 18 | 5 | 0 | 17 |
| Cashews | 18 | 3 | 6 | 19 |
| Turkey | 17 | 1 | 3 | 1 |
| Tofu | 16 | 2 | 0 | 17 |
| Tahini paste | 16 | 1 | 1 | 12 |
| Hazelnuts | 15 | 1 | 4 | 13 |
| Quinoa | 14 | 36 | 0 | 16 |
| Barley | 13 | 45 | 1 | 7 |
| Edamame | 12 | 3 | 2 | 8 |
| Cottage cheese, low fat | 12 | 1 | 3 | 2 |
| Eggs, whole | 11 | 0 | 2 | 11 |
| Eggs, whites only | 11 | 0 | 1 | 0 |
| Whole grain bread | 9 | 7 | 7 | 2 |
| Chickpeas / Garbonzo beans | 9 | 15 | 5 | 7 |
| Macadamias | 7 | 1 | 4 | 32 |
| Black beans | 6 | 8 | 1 | 1 |
| Greek yoghurt, low fat | 6 | 0 | 0 | 12 |
| Regular Yoghurt | 5 | 0 | 0 | 1 |
| Kidney beans | 5 | 12 | 2 | 2 |
| Plain soy milk | 3 | 5 | 4 | 7 |
| Brown rice | 2 | 15 | 0 | 2 |
(Please note that the table above is an estimate and should be used as a guide only - it is best to judge each food from the ingredients label on the packet or using a calorie counter style tool)
As we can see from the above table, while there are a number of sources very high in protein available for consumption, it is important to be careful of the level of fats associated with such foods. For example, nuts. Keep in mind that in moderation a few nuts won't hurt us - but when you are looking to lose those last few kilos, even healthy fats matter. So whilst nuts are high in protein and ok to substitute for say, one of our sources of protein per day, we need to be very wary of their high fat content.
So how much protein does a person need to consume in an ideal environment for muscle growth / fat loss? The average adult should be consuming as a minimum 0.75g / kg bodyweight daily. So for a person weighing 70kg, they should be consuming 52.5g protein a day as a minimum. This equates to about 1 full cup of lentils, or a serving of 255g of seitan. For those serious about fat loss, I recommend to have protein equivalent to the size of your palm (hand), five times a day minimum. This should add up to the above recommendation.
So, would I recommend becoming a vegetarian or vegan purely on the basis of losing fat off your body? Absolutely not. But if you are a vegetarian or vegan already, I am hoping that this article will stimulate you to look carefully at your diet and analyse whether the sources of protein you are consuming are suitable for your fat loss goals. For those vegetarians out there wanting to keep in shape and considering becoming a vegan it is also important to realise the limitations this will place on your protein requirements, if you are looking to build muscle and lose fat.
It is important to note that many people, vegetarians and non-vegetarians, suffer from the same issue of eating too much fat in their diets. No matter what your standing on this matter, it is important to always look at whether you are consuming sufficient protein in your diet and that the sources of protein your are choosing are suitable to your needs. I support all vegetarians and vegans who monitor the protein in their diets and maintain an active and healthy lifestyle.
