Cutting back animal products completely could lead to nutritional deficiencies, warn nutrition experts

By Oliver Morrison

- Last updated on GMT

Cutting back animal products completely could lead to nutritional deficiencies, warn nutrition experts

Related tags British nutrition foundation Iron Iodine

Research from the British Nutrition Foundation, a charity that provides information on healthy eating, suggests there’s limited consumer demand for more healthy and sustainable diets owing to a lack of key nutrients such as iron and iodine in vegan and vegetarian diets.

Big food companies are doubling down on plans to champion plant-based food. Up to 30% of consumers are keen to transition to a ‘flexitarian’ diet with less or no meat, according to a global study conducted by Nestle in 2017. Unilever has an annual global sales target of €1 billion from plant-based meat and dairy alternatives, within the next five to seven years. Earlier this year JBS, the world's biggest meat processor, acquired Dutch plant-based meat maker Vivera in a €341 million deal. Most recently, Danone has just said it plans to continue to expand its high-growth plant-based beverage business​. 

But fresh research from the British Nutrition Foundation, a charity that provides information on healthy eating, suggests limited consumer demand for more healthy and sustainable diets. In a new review paper, the BNF said that government-backed healthy eating advice, such as the UK’s Eatwell Guide​, can deliver health and environmental benefits if followed at a population level.

The Eatwell Guide describes a diet that is rich in foods from plants including vegetables, fruit, wholegrains, beans and other pulses, nuts and seeds, and plant-based meat alternatives that provide essential nutrients and are lower in salt and saturated fat. Eatwell guidelines also include some meat, dairy, fish and eggs. A UK study​ found that following the Eatwell Guide’s recommendations more closely would lower the greenhouse gas emissions (GHGE) of current adult diets by 30%, and reduce water use by 4%, as well as reducing mortality risk by up to 7%.

However currently less than 1% of people are achieving all of the Eatwell Guide recommendations.

Nutritional deficiencies holding back plant-based

The charity added that a lack of key nutrients such as iron and iodine in vegan and vegetarian diets means they are unlikely to be embraced by the mass market. While vegetarian and vegan diets can deliver environmental benefits in terms of GHGE and land use associated with food production, the review highlighted that they are unlikely to be widely adopted based on current adherence rates and may reduce intakes and/or bioavailability of some essential nutrients found in foods such as meat, fish, milk and eggs, for example iron, zinc, calcium, iodine, and vitamin B12.

The BNF added that ready-prepared ‘plant-based’ foods have attracted a ‘health halo’ that is not always deserved. Some plant-based alternatives may not contain important vitamins and minerals found in animal-based equivalent products (such as the calcium and iodine provided by cow’s milk).  

Prof Judy Buttriss, Director General of the British Nutrition Foundation and co-author of the review said: “Looking at the available evidence we recommend that an obvious step is to work together with others in the field of nutrition and beyond to promote diets aligned with the UK’s Eatwell Guide. An advantage of this kind of plant-rich diet, which can still include some meat, fish, dairy products and eggs, is that it is based on dietary patterns already familiar in the UK and already being adopted to some extent by many of us. However, currently less than 1% of people are achieving all of the Eatwell Guide recommendations, and so there is room for improvement for almost all of us.”

Healthy eating advice already acknowledges the need to moderate consumption of red and processed meat and this was also a consistent finding in the studies reviewed by the BNF. However, evidence did not suggest the need to cut out meat or other animal-derived foods entirely in order to achieve a healthier and more sustainable diet. In the UK, intake of red and processed meat across the population has been falling and is already at an average of 56g per day amongst adults aged 19-64, within the limit suggested for health (less than 70 g/day on average across the week). However, around a third of people are still eating more red meat than recommended.

As highlighted in the recent National Food Strategy​ recommendations from Henry Dimbleby, if everyone in the UK complied with the current advice, this would reduce consumption of red and processed meat overall by about a quarter.

How to make diets healthier and more sustainable

While there is no ideal ‘one-size-fits-all’ solution, there are some actions that everyone can take now that are likely to benefit both their own health and the environment, said the BNF:

1.​        Follow the Eatwell Guide ​which shows the proportions of foods from the main food groups needed to achieve a varied and healthy diet. As well as reducing the environmental impact of diets in the UK on average by about a third, this style of diet will likely improve the health of the UK population by reducing the number of new cases of heart disease, stroke, cancer and type 2 diabetes, and helping ensure nutrient needs to support growth and wellbeing are met for all age groups.

2.​        Eat more fruit and vegetables​. Fruit and vegetables are a good source of important vitamins, minerals and fibre. Eating at least five portions (80g each) every day of a variety of fruit and vegetables can help to reduce the risk of heart disease, stroke and some types of cancer later in life. Fruit and vegetables also tend to have a lower environmental impact in terms of GHGE and land use than some other types of food.

3.​        Diversify and shift the balance of protein intake towards more plant-based sources of protein. ​Animal foods provide high-quality protein and essential vitamins and minerals, such as calcium, iron, zinc, iodine and vitamin B12 often in a form that is easier to absorb and use. However, we should also aim to expand our choice of protein-containing foods to include more plant-derived sources, such as beans and other pulses, nuts, seeds, and plant-based meat alternatives, for example those based on pulses such as soya or on mycoprotein, provided they are not high in saturated fat or salt.

4.​        Limit foods high in fat, salt or sugar. ​As well as being less healthy choices, foods such as cakes, biscuits, pies and pastries also contribute to GHGE associated with our diets, and other impacts on the environment such as water use. Limiting these foods in line with healthy eating guidance can reduce the environmental footprint of diets, especially if such foods are typically consumed in large amounts.

Don’t ditch the dairy

Although it is sometimes assumed that the ‘eat less’ message applies equally to all animal-derived foods, the evidence reviewed in the BNF paper did not consistently suggest the need to reduce consumption of milk and yogurt or eggs, possibly reflecting trade-offs between the high nutrient density of these foods relative to their more intermediate environmental impact.

Decisions about appropriate substitutes for animal-sourced foods all too often just focus on total protein, but the review emphasised that this is not enough. Increasing the variety of protein-containing foods we choose to eat, including more plant-derived proteins, is part of having a healthier, more sustainable diet. However, most people already eat more than enough protein, the BNF stated and ‘therefore we should consider the overall nutrient profile of foods’. “As well as protein we also need to consider delivery of the many other essential nutrients that animal-sourced foods provide, if we are to ensure that people’s nutrient intakes do not suffer as dietary patterns shift.”

Animal-sourced products currently provide over a quarter of iron, a third of vitamin A and about half the calcium, zinc, iodine and riboflavin in UK adult diets. Therefore, there needs to be careful consideration of how people will consume enough of these essential nutrients in a form that can be easily absorbed by the body if reducing their intakes of animal-derived foods, Buttriss concluded.

“While the evidence-base on sustainable food systems has grown significantly in recent years, all too often nutritional quality and delivery of essential nutrients is not considered in judgements about the environmental impact of foods and diets,”​ she said. “It’s vital that nutrition is central in discussions about transformation of food systems so that we don’t risk encouraging dietary changes that might benefit the environment but could be detrimental to people’s health.”

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