Vegetarian diets explained
Vegan, flexitarian, lacto-vegetarian, all very popular terms nowadays. But what actually are the options if you want to consume a plant-based diet? And more importantly, what are the points of attention when following such a diet? In this blog post we explain the ins and outs of a vegetarian diet.
What does a vegetarian diet look like and what are the points of attention?
People that follow a vegetarian diet don’t consume meat. Besides that, there are no strict rules and it can differ per person what a vegetarian diet looks like. A person can choose to consume eggs and dairy, but no fish. This is called a lacto-ovo-vegetarian diet. Others might choose to consume both eggs and dairy products as well as fish. This is called a pescetarian diet.
Since vegetarians choose not to consume meat, it is of high importance to replace the essential nutrients that are naturally present in meat. These are protein, iron, and vitamin B1 and B12.
What is protein and what are important food sources?
Proteins are, like carbohydrates and fats, essential nutrients for the human body. Proteins are built of amino acids. Amino acids are important building blocks for our body. They are needed for the construction and maintenance of all of our body cells, including our muscles. Proteins can be either animal- or plant-based, and they are particularly abundant in meat, fish, egg, dairy, bread, grain products, legumes and nuts.
For vegetarians, a big part of their protein intake comes from plant-based sources. The amino acids in plant-based proteins are less optimal for the human body compared to animal-based proteins, and are sometimes harder to digest. A higher protein intake will solve this problem. An adult needs on average 0.83 grams protein per kilogram of bodyweight. However, a vegetarian has a protein requirement which is 1.2 times higher.
Table 1: Vegetarian protein sources
Food product | Portion size | Amount of protein |
Low-fat quark | 1 bowl (150 g) | 12,8 g |
Cheese | 1 pre-cut slice (30 g) | 9,6 g |
Low-fat yogurt | 1 bowl (150 g) | 6,3 g |
Chicken egg | 1 egg (50 g) | 6,2 g |
Unsalted nuts | 1 handful (25 g) | 5,4 g |
Lentils | 1 serving spoon (60 g) | 5,3 g |
Semi-skimmed milk | 1 glass (150 ml) | 5,1 g |
Kidney beans | 1 serving spoon (60 g) | 5,0 g |
Chickpeas | 1 serving spoon (60 g) | 4,6 g |
Whole grain bread | 1 slice (35 g) | 3,9 g |
Whole grain pasta | 1 serving spoon (60 g) | 3,4 g |
Oatmeal | 1 serving (20 g) | 2,6 g |
Broccoli | 1 serving spoon (50 g) | 2 g |
What is iron and what are important food sources?
Iron is an important mineral for the formation of hemoglobin, which is an essential element of red blood cells. Red blood cells transport oxygen through the body. Iron can be present in our diet in two forms: heme iron and non-heme iron. Heme iron is only found in animal products, whereas non-heme iron is found in both animal and plant products. The absorption of heme iron in our body is more efficient than the absorption of non-heme iron.
The absorption of non-heme iron can be improved by including products rich in vitamin C – like fruits and vegetables – in the meal. Well-known plant-based sources of iron include bread, whole grain products, legumes, nuts and leafy green vegetables. The recommended daily intake of iron is 11 mg per day for women over the age of 50, and for men. The recommended daily intake for women aged between 16 and 50 years is 16 mg per day.
Table 2: Vegetarian iron sources
Food product | Portion size | Amount of iron |
Unsalted nuts | 1 handful (25 g) | 1,7 mg |
Lentils | 1 serving spoon (60 g) | 1,7 mg |
Chicken egg | 1 egg (50 g) | 1,2 mg |
Spinach | 1 serving spoon (50 g) | 1,2 mg |
Kidney beans | 1 serving spoon (60 g) | 1,2 mg |
Chickpeas | 1 serving spoon (60 g) | 1,1 mg |
Whole grain pasta | 1 serving spoon (60 g) | 1,0 mg |
Oatmeal | 1 serving (20 g) | 0,8 mg |
Whole grain bread | 1 slice (35 g) | 0,7 mg |
Kale | 1 serving spoon (50 g) | 0,5 mg |
Potatoes | 1 serving spoon (100 g) | 0,5 mg |
What is vitamin B1 and what are important food sources?
Vitamin B1 (thiamine) plays an important role in the provision of energy of the body since it helps cells to change carbohydrates into energy. Besides, vitamin B1 is important for proper functioning of the heart muscle, nervous system and the brain. Vitamin B1 is particularly present in meat products, milk and milk products, bread, grain products, potatoes and vegetables. Adult men require between 0.9 and 1.2 mg vitamin B1 per day. Adult women are advised to have a daily intake between 0.7 and 0.8 mg vitamin B1.
Table 3: Vegetarian sources of vitamin B1
Food product | Portion size | Amount vit. B1 |
Potatoes | 1 serving spoon (100 g) | 0,06 mg |
Semi-skimmed milk | 1 glass (150 ml) | 0,06 mg |
Low-fat yogurt | 1 bowl (150 g) | 0,05 mg |
Whole grain pasta | 1 serving spoon (60 g) | 0,05 mg |
Whole grain bread | 1 slice (35 g) | 0,04 mg |
Vegetables, general | 1 serving spoon (50 g) | 0,03 mg |
How does a vegetarian meet the requirements for the intake of vitamin B12?
The human body needs vitamin B12 (cobalamin) for the formation of red blood cells and a proper functioning of the nervous system. Vitamin B12 is only found in animal products. Vegetarians are therefore dependent on the consumption of eggs, cheese and milk products for their intake of vitamin B12. Men and women aged above 14 years have a recommended daily intake for vitamin B12 of 2.8 mg per day.
Table 4: Vegetarian sources of vitamin B12
Food product | Portion size | Amount vit. B12 |
Low-fat quark | 1 bowl (150 g) | 1,1 mg |
Chicken egg | 1 egg (50 g) | 0,8 mg |
Cheese | 1 pre-cut slice (30 g) | 0,7 mg |
Semi-skimmed milk | 1 glass (150 ml) | 0,7 mg |
Low-fat yogurt | 1 bowl (150 g) | 0,6 mg |
Conclusion
Eating (more) plant-based is not the same for everyone. Different types of vegetarian diets exist in which the points of attention regarding nutrients differ as well. By choosing the right food products, eating (more) plant-based can be implemented in a responsible way without possible deficiencies.
References
- Postma-Smeets, A., & Van Dooren, C. (2018, November). Vegetarisch en veganistisch eten. Consulted on 31 March from Voedingscentrum: https://www.voedingscentrum.nl/Assets/Uploads/voedingscentrum/Documents/Ontwerp_Vegetarisch%20en%20veganistisch%20eten_defLR_2018.pdf
- Voedingscentrum. (nd). Vegetarisch, veganistisch en flexitarisch eten. Consulted on 31 March from Voedingscentrum: https://www.voedingscentrum.nl/encyclopedie/vegetarisme-veganisme.aspx
- Voedingscentrum. (nd). Eiwitten. Consulted on 31 March from Voedingscentrum: https://www.voedingscentrum.nl/encyclopedie/eiwitten.aspx
- Gezondheidsraad. (2021). Voedingsnormen voor eiwitten. Den Haag: Gezondheidsraad.
- Rijksinstituut voor Volksgezondheid en Milieu. (2019). Nederlands Voedingsstoffenbestand (NEVO). Consulted on 31 March from Nevo-online: https://nevo-online.rivm.nl/
- Rijksinstituut voor Volksgezondheid. (2020). Portie-online. Consulted on 31 March from Portie-online: https://portie-online.rivm.nl/
- Gezondheidsraad. (2018). Voedingsnormen voor vitamines en mineralen voor volwassenen. Consulted on 31 March from Gezondheidsraad: https://www.gezondheidsraad.nl/documenten/adviezen/2018/09/18/gezondheidsraad-herziet-voedingsnormen-voor-volwassenen
- Voedingscentrum. (nd). Thiamine (vitamine B1). Consulted on 31 March from Voedingscentrum: https://www.voedingscentrum.nl/encyclopedie/vitamine-b1.aspx#blok1
- Voedingscentrum. (nd). Vitamine B12 (cobalamine). Consulted on 31 March from Voedingscentrum: https://www.voedingscentrum.nl/encyclopedie/vitamine-b12.aspx