Can vegetarian diets be healthy?

HCPC Registered Dietitian Mei Wan covers all your frequently asked questions about vegetarian diets. 

Take home message... 

A vegetarian diet normally reduces or omits the intake of animal-based foods. With careful planning, (including sources of foods (and supplementation, if advised by a doctor,) that are rich in omega-3 fats, calcium, iron, zinc, iodine, and vitamin B12), a vegetarian diet may improve your health and reduce the risk of some chronic diseases.  

What is a vegetarian diet? 

A dietary intake that limits or avoids foods from animals is classed as a vegetarian diet.

There are a variety of reasons why someone chooses a vegetarian diet: 

• Health based, for example, cholesterol-lowering, weight management 
• Personal preferences and beliefs 
• Animal ethics 
• Religious beliefs and traditions 
• Environmental 
• Economic

Did you know, there are quite a few sub-categorisations of vegetarianism: 

• Lacto-ovo vegetariansim: includes dairy foods and eggs but no meat, poultry or seafood. 
• Ovo-vegetarianism: includes eggs but avoidance of all other animal foods, including dairy. 
• Lacto-vegetarianism: includes dairy foods but excludes eggs, meat, poultry and seafood.
• Pesco-vegetarianism: includes seafood, dairy foods and eggs but not meat or poultry.
• Veganism: excludes all animal products including honey, dairy and eggs.
• Semi-vegetarianism (or flexitarians): includes some meat, seafood, poultry, eggs and dairy
• Ento-veganism: follows a vegan diet but includes edible insects for nutritional and environmental reasons 

How can I ensure my vegetarian diet is healthy? 

Vegetarianism can be healthy and delicious as its foundation is predominately on beans, whole grains, vegetables, seeds, nuts, and fruit.

If you stick to whole foods, as with any chosen dietary preferences, it can provide all the nutrients required for overall health.

A vegetarian diet may also reduce the risk of cardiovascular diseases, hypertension, type 2 diabetes and some cancers as well as assist in weight management. 

Are there any nutritional risks that I should be aware of? 

Minimising or omitting animal-based foods does mean you need to be aware of a few nutrients to ensure your dietary intake is wholesome and healthy... 

• Protein: Ensure each meal contains a serving of protein-rich foods such as beans, chickpeas, lentils, soya products, eggs and dairy products (if you eat the latter two). Meat substitutes (for example, Quorn) are good sources of protein but be mindful of the salt and fat content by always reading the food labels. 
• Omega-3 fatty acids: If omitting fish from your diet, you need to ensure that you consume fats that are rich in omega-3 which are important for health. Essential fats in non-animal foods such as vegetable oils, chia seeds, linseeds, hemp seeds, flax seeds (and flaxseed oil), soybean products, green leafy vegetables and especially walnuts can be converted by the body.
  • The highest source of omega-3 fats are in oily fish like mackerel, salmon, sardines, pilchards, trout, whitebait, kipper, herring, and fresh tuna (not tinned tuna). There are also omega-3 fortified products such as eggs, spreads, milk, yoghurt, and dairy-free products. In the UK, there are currently no recommendations for the use of omega-3 supplements due to the lack of robust evidence.
  • Always speak to your GP if you think you could be at risk of low omega-3 fats intake. Rather than cod liver or fish liver oil, choose an omega-3 supplement that contains 450mg of EPA and DHA per daily adult dose. Ensure not to have more than 1.5mg of vitamin A (1500ug) daily from supplements and food as a high dose of vitamin A is toxic [1]. For a plant-based option, algae-based supplements are widely available.
• Vitamin B12: This is only found in animal foods, so you need to get this from fortified foods or as a supplement if you are avoiding all animal foods (always speak to your doctor before taking supplements).
  • Breakfast cereals, soya yoghurts, plant-based dairy alternatives and yeast extracts are the only reliable sources of vitamin B12.
  • Supplementation with greater than the Recommended Daily Allowance (RDA) of 1.5 micrograms is adequate as absorption and personal need vary a lot [2].
  • The Vegan Society suggests 1) eat fortified foods twice a day (3 micrograms of vitamin B12 a day or 2) take a vitamin B12 supplement to ensure 10 micrograms daily or a minimum of 2000 micrograms weekly.
• Vitamin D: Our body makes vitamin D from your skin’s exposure to the sun. Oily fish and some fortified foods contain vitamin D but in the winter months in the UK, as a population, vegetarian diet or not, we should all consider taking a supplement (from October to March [3]) – always speak to your GP about taking the correct dose. Adults should not exceed 10 micrograms a day [4]. 
• Calcium: If you are not eating dairy foods that are rich in calcium, ensure to include fortified foods, nuts, leafy green vegetables, red kidney beans, soya products and sesame seeds. Adults require 700mg a day [5]. 
• Iron: Animal foods contain a form of iron that is more easily absorbed compared to plant foods containing iron. You can still obtain iron from beans, seeds, lentils, green leafy vegetables, whole grains, peas and nuts. A top tip to increase iron absorption is to eat vegetables/fruit with it as they are rich in vitamin C. Plus, avoid drinking caffeine (tea or coffee) with a meal as this blocks the absorption of iron – instead, wait 1 hour to enjoy the hot drink. 
• Zinc: Like iron, the absorption of zinc is lower in non-animal foods. Alongside eggs and milk, nuts, seeds, beans, mushrooms and some fortified breakfast cereals.
• Iodine: If you exclude dairy products and seafood, you might be at risk of iodine deficiency [6]. You may wish to include seaweed or iodine-fortified foods, but an excess of iodine is also unhealthy. There are currently no official UK recommendations for adults so always speak to your doctor before starting (any) supplements. 

Some Final Thoughts     

In summary, vegetarian diets can be equally nutritious and balanced as animal-based diets. You just need to ensure that you carefully plan your meals to include all the essential nutrients (especially vitamin B12 and calcium).  

References

[1] Scientific Advisory Committee on Nutrition (2004), Advice on Fish Consumption: Benefits and Risk.

[2] Public Health England. Government recommendations for energy and nutrients for males and females aged 1 – 18 years and 19+ years (2016)

[3] NICE, PHE and SACN publish rapid COVID-19 guidance on vitamin D | News | News | NICE 

[4] Scientific Advisory Committee on Nutrition (2016), Vitamin D and Health.

[5] Nutrition_and_Bone_Health_-_with_particular_reference_to_calcium_and_vitamin_D (1998) 

[6] Scientific Advisory Committee on Nutrition (2016), Iodine and Health.

For further information 

• Vegetarian, vegan and plant-based diet | British Dietetic Association (BDA) 
• Omega-3 | British Dietetic Association (BDA) 
• The Vegan Society | 
• Vitamin D | British Dietetic Association (BDA) 
• Calcium | British Dietetic Association (BDA) 
• Iron | British Dietetic Association (BDA) 
• Iodine Food fact Sheet | British Dietetic Association (BDA)