6 Myths about plant-based diets, debunked by doctors

Let’s start where most people are when thinking about plant-based diets. They see a plant-based diet as restricting their food choices. At best, this is going to leave them feeling frustrated, hungry and bored with meals. At worst, they are going to experience weakness from a lack of protein and iron. Forget building muscle bulk and improving fitness. Surely a vegan struggles with having enough energy to perform even normal tasks, as over time the absence of a "complete" protein source in their diets will lead to emaciation?

Fortunately, we can report that this is far from the truth. The phrase "eat the rainbow" describes aiming to eat at least 30 different plants a week (there are over 20,000 edible ones, so you will find an explosion in your food choices once you start to look). If you are eating enough calories from this range of foods, you will be eating enough protein and iron, as all plants are a source of protein, and rich sources of iron are spinach, beans, nuts, and dried apricots. Even a large potato contains 8 grams of protein, whilst tasty super-sources are tofu, tempeh (fermented soya beans) and seitan (a mock meat made from wheat gluten), with around 20–30 grams a portion. Women need on average 45 grams and men 55 grams of protein a day, depending on your life stage and athletic ambition.

Sadly, all healthy diets come out as more expensive than simply consuming the cheapest 2,000 calories a day. The good news is that studies show a healthy whole-food plant-based diet—one based on fruits, vegetables, nuts, seeds, wholegrains and legumes—is more affordable than the omnivorous equivalent.

In simple terms, beans and lentils are cheaper than chicken and mince. There is no getting away from the fact that most people consume way too little fibre, and since there is no fibre in meat, chicken, fish or dairy, even a healthy omnivorous diet will need large portions of fruit and vegetables. Batch cooking with pressure or slow cookers to save energy, using canned beans and vegetables, and choosing in season fresh fruit and vegetables are all ways to put together delicious, cheap meals.

Ultra-processed meat replacement foods may not be the healthiest, as well as often pricier than their meat counterparts, but perhaps surprisingly they still pack in more health points than the red meat original. So they are great transition foods while you find new confidence in the kitchen.

A veggie sausage on a school menu is a healthy nutritious alternative to the pork one, and very likely acceptable in terms of taste and texture. So until we are bringing up our kids on bean stew, we’re glad plant-based sausages, lasagnes, and chick’n breasts are easy to find.

Yes, if you are eating 100 per cent plant-based we recommend you take a B12 supplement, because you won’t be consuming animals who are themselves supplemented with B12. A vitamin D supplement is also recommended, as it is for the majority of the population, since we all struggle to maintain vitamin D levels especially in winter due to the lack of sunlight.

Even amongst those eating meat, vitamin B12 deficiency is relatively common, not least because of the widespread use of medications which prevent absorption such as metformin (for diabetes) and proton pump inhibitors (for reflux). Taking an all round supplement which contains a safe amount of all these important nutrients is a small adjustment in a diet which has been shown to drastically reduce rates of cardiovascular disease, diabetes, and cancer.

This myth comes in many forms, from the fear that soya (which contains isoflavones, otherwise known as plant oestrogens) could cause breast cancer in women and impotence and breast development in men, to the idea that soya for the plant-based is leading to the destruction of rainforests.

In fact, its high protein content and isoflavones make soya a superfood, shown in numerous studies to be associated with reduced rates of breast cancer in women, and benefits for prostate health in men. Moreover, it’s not people eating more plants that’s driving the loss of wilderness; 93 per cent of soya is used for animal feed and biofuels.

While dairy is a source of calcium and vitamin D, these nutrients find their way into milk through, you’ve guessed it, cows eating plants. So you shouldn’t be surprised to learn that there are plenty of plant foods which are great sources of calcium including nuts and seeds, leafy greens, beans, and fruit.

But if you want to keep things easy, most plant milks and soya yoghurts are fortified to dairy-equivalent levels with calcium and vitamin D, meaning you can healthfully swap out cow’s milk for soya milk on your cereal.