The Flexitarian Diet

What is the flexitarian diet?

What are the benefits of the flexitarian diet, especially when compared with either a vegetarian or vegan diet?

Are there foods it would be good to avoid on a flexitarian diet?

Are all meats equal and valid choices on a flexitarian diet? Or would following a flexitarian diet be an opportunity to give up, for example, red meat, which has been linked to various health issues?

The flexitarian diet advises that we eat meat in moderation but doesn’t specify a type. There is, however, strong evidence around eating a lot of red meat, such as pork, beef, lamb and processed meat as causes for colorectal cancer. Examples of processed meat include bacon, spam and ham with the World Cancer Research Fund advising that you avoid processed meat completely [4].

We do, however, need protein in our diet for maintaining and repairing our muscles, but we currently eat more of it than we need to in the UK. We don’t need to eat meat every day and when we do, I advise eating less but better quality. Studies show that there are some differences in the nutritional composition of organic grass-fed vs grain fed beef. Organic grass-fed beef usually contains less saturated fats, more omega-3 fatty acids and contains more vitamin A, E and other nutrients like antioxidants [5]. Knowing where your meat comes from is also important for ethical and environmental reasons.

How can you ensure you’re getting all the nutrients you need on a flexitarian diet?

If well-planned, a flexitarian diet can be healthy, and you should be able to get most of your nutrition from food. There are some nutrient deficiencies to be aware of when you cut down on animal products. This includes the following:

Vitamin B12 – this is a vitamin that is important for normal function of the nervous system, blood cell formation, energy and mood. It is only found in animal products, so depending on how stringent you are when excluding animal products, you may need to take a supplement for this. Good food sources are fortified nutritional yeast, yeast extract, fortified cereals, such as brand flakes, or plant milks, such as soya milk. The UK Reference Intake advises that people should be having 1.5mcg per day.

Zinc – Zinc is needed for multiple processes in the body e.g. DNA synthesis and brain function, and we need a daily supply of it as it is not stored in our body. Good food sources are fortified nutritional yeast flakes, pumpkin seeds, cashew nuts, tempeh, quinoa and brown rice. Men are advised to take 9.5mg/day and women 7.5mg.

Calcium – Adults need 700mg a day for healthy bones, teeth, blood clotting and neurotransmission and dairy products are a rich source. Choose fortified plant milks, tofu, kale, sesames seeds or tempeh as a plant boost of calcium.

Iron – Iron is needed to make haemoglobin found in your red blood cells. Iron is found in plant foods but is more easily absorbed from animal products. Substances called phytates, found in some plant foods, reduce the amount of iron that is available to your body. When eating a rich source of iron, such as spinach, kale or legumes, combine the meals with a food high in vitamin C to aid absorption, such as oranges, peppers or a kiwi. Aim for 8.7mg for men and 14.8mg for women a day.

Iodine – Milk and dairy are a key source for iodine in our diets. Iodine is a crucial component of a thyroid hormone called thyroxine needed for a range of bodily processes and a healthy metabolism. If cutting down on milk foods, choose fortified dairy alternatives. The UK Reference Intake is 140mcg per day.

Omega-3 fatty acids – Flexitarians should be wary of getting enough omega-3 fatty acids in their diet if they are cutting down on fatty fish. Plant-based sources of omega-3 include alpha-linolenic acid (ALA) from walnuts, hemp seeds, chia seeds and flaxseeds.

Should you be taking supplements too or can you get all you need from food?

Ideally you should be able to get all you need from your diet if you plan your meals carefully. The truth is we all live busy lives and it may not always be possible to get enough of key vitamins or minerals from your food (such as B12 and omega-3) and you might need to choose a fortified food product or supplement to fill the gap. Be careful not to overdose on mega strength supplements or believe all the claims, as these can also be harmful, and the vitamin industry is not regulated. If you think you need some help with your diet, please go see your GP or a registered dietitian.

One vitamin we cannot get from our diet is vitamin D (it is produced in our skin when we are in the sun), so it is advised everyone takes a vitamin D supplement of 10mcg. Vitamin D helps regulate the amount of calcium and phosphate in the body, which is needed to keep bones, teeth and muscles healthy [6].

How close is the flexitarian diet to the ideal diet for most humans?

I think that a flexitarian diet, if it is rich in fruits, vegetables, legumes, whole grains, nuts and seeds, oily fish with moderate meat and dairy and low in processed, sugary and fatty foods, mirrors the Mediterranean Diet.

The Mediterranean diet is the most researched dietary pattern in the world and there is substantial, quality evidence to show that it can reduce the risk of having a heart attack or a stroke, is linked with less weight gain, a lower risk of type 2 diabetes, better gut health, improved mental health and healthier ageing.

At Field Doctor, our meals are based on the Mediterranean Diet because the evidence for it is so strong across different population groups (so a good benchmark for an ideal diet) and it is nutrient-dense, rich in antioxidants, good unsaturated fats and fibre.