What is a healthy, sustainable diet?

We aim to give people access to reliable science-based information to support anyone on their journey towards a healthy, sustainable diet. In this section you can read about some general principles we can all follow to aim for a healthier and more sustainable diet.

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A healthier and more sustainable diet

How can we all eat a diet that is healthy, affordable and accessible for everyone, and also has a lower impact on the environment? How can we produce more food to feed a growing population at the same time as using fewer resources, such as land and water, and energy? These are some of the issues discussed in this article, which provides information on what is meant by a healthy and sustainable diet and includes some tips on how we can make more sustainable food and drink choices.

This article looks at:

How does the food we eat affect the environment?

The balance of foods that we consume is not only important for our own health, but also the health of our planet. At present, 1 in 5 deaths worldwide are linked to consuming a poor quality diet. Food production also has a big impact on the environment. At present, our global food system is responsible for:

  • between a fifth to one-third of all greenhouse gases (including methane and carbon dioxide) released by human activities, which contribute to climate change
  • over two-thirds of global freshwater use, and
  • over a third of global land area.

At the same time, we have a rising global population, which is expected to reach almost 10 billion people by 2050.

This will mean increased demand for food, especially animal-based foods like meat and milk, as populations become more prosperous. This higher demand for food will place extra pressure on our current food system, which is already being affected by climate change.

Finding solutions to address these changes is one of the biggest challenges facing us in the 21st century. To improve our health and to combat the effects of our current food system on the environment, we need to change the way we produce food and how we consume it. This will help ensure there is enough safe and nutritious food for everyone, produced in a sustainable way that protects our planet while improving human health.


A dish of chicken tomatoes and chickpeas

What do we mean by a healthier and more sustainable diet?

We all know that a healthy and balanced diet is important for good health. However, when it comes to defining a diet that is healthy and sustainable, there are lots of factors to consider. This includes good nutrition and a lower environmental impact, but also the right balance of foods (and drinks) that is affordable and acceptable, so that dietary changes are fair and equal for everyone. The need to balance all these factors makes it difficult to know for sure what a healthier and more sustainable diet looks like exactly.

Overall, it can be challenging for us to know what the environmental impact of a product is when we are deciding what to buy while shopping. Our understanding of which foods (and drinks) we should or should not include in a healthier and more sustainable diet is still developing, and there is new research coming out all the time. There is unlikely to be any ‘one-size-fits-all’ solution that applies to everyone. But the good news is that there are some changes we can make to our diet that are likely to benefit both our health and that of the planet.


What changes can I make to eat a healthier and more sustainable diet?

1. Eat a more 'plant-rich' diet

Research shows that eating an overall diet that is plant-rich can have benefits for our health and reduce the environmental impact of what we eat at the same time. In the UK, the Eatwell Guide provides a guide that everyone (over 2 years of age) can follow to eat a healthy, varied diet, which emphasises plant source foods, but can also include some meat, dairy, fish and eggs. It has been estimated that if everyone in the UK ate a diet in line with the Eatwell Guide, then this would reduce the environmental impact of our diets in the UK on average by about a third, including less land and water use, and lower emissions of greenhouse gases. This style of diet would also improve the health of the UK population by reducing the number of new cases of heart disease, stroke, cancer and type 2 diabetes.

Top of the list is to focus on variety in our diet. We should aim to choose a variety of foods from each of the groups shown in the Eatwell Guide to achieve a healthy and balanced diet. For most of us, this means finding ways to get more vegetables, fruit, beans and other pulses (such as lentils) and wholegrain foods into our diet, while limiting foods that are high in fat, salt and sugar, and rebalancing our choice of protein-providing foods towards plant sources. More advice on how to do this is provided below.


2. Get your 5 A DAY

Fruit and vegetables are a good source of important vitamins, minerals and fibre. Eating at least five portions (80g each) of a variety of fruit and vegetables a day is recommended to help reduce the risk of heart disease, stroke and some types of cancer.

Fruit and vegetables also tend to have a lower environmental impact in terms of greenhouse gases and land use than some other types of food. Only a third of UK adults currently meet the 5 A DAY recommendation on average. Here are a few ideas for ways to increase your fruit and vegetable intake:

  • Try having an apple, banana or satsuma (or other piece of seasonal fruit) as a mid-morning or mid-afternoon snack.
  • Add extra fresh, canned or frozen vegetables when cooking your favourite recipes, such as spaghetti bolognese, curries, soups or stews.
  • Sprinkle a handful of seasonal berries or chopped banana on your breakfast cereal or porridge in the morning.


3. Expand and shift the balance of your protein intake towards more plant-based sources

Meat is a good source of protein and provides essential vitamins and minerals, such as iron, zinc and vitamin B12, and evidence suggests that it is not necessary to cut out meat or other animal source foods from our diet entirely to be more sustainable, as true sustainability should consider not only the environment but also other important factors such as health, cost, accessibility and affordability. But we should also aim to expand our choice of protein options to include more plant-based sources in our diet. Try to vary your choice of protein-rich foods by eating more beans and other pulses (such as lentils), nuts, seeds and plant-based meat alternatives (such as soya- or mycoprotein-based alternatives, or tofu) that are not high in saturated fat or salt. Check the traffic light label on the front of packs and go for more greens and ambers and fewer reds. If the product does not display traffic light labelling, remember high in saturated fat is more than 5g per 100g (or more than 6g per portion) and high in salt is more than 1.5g per 100g (or more than 1.8g per portion).

Here are a few suggestions for how to increase your intake of plant-based protein foods:

  • Add a can of beans or chickpeas to replace some (or all) of the meat when cooking dishes such as chilli or curry. Canned pulses are an affordable and convenient protein source and also provide fibre and other essential nutrients.
  • Try a handful of unsalted nuts or seeds as a healthier snack.
  • Use plant-based protein such as tofu, tempah, soya mince or textured vegetable protein (TVP) or mycoprotein to make some of your favourite dishes, like stir fries or bolognese.


4. Limit foods high in fat, salt and sugar

We all know foods such as cakes, biscuits, pies and pastries are not healthy choices, but they can also contribute to the greenhouse gas emissions associated with our diets, as well as land and water use. Limiting these foods in our diet can be a good way to reduce our environmental footprint, especially if we tend to eat these foods often or in large amounts. Some ways we can do this include:

  • Be portion wise: If you occasionally enjoy snacks high in fat, salt or sugar, try to portion them out to avoid eating lots of calories in one go. For example, put a handful of crisps or nuts in a bowl and leave the rest for later. For more information on healthy portion sizes read our 'Get portion wise!' page.
  • Out of sight, out of mind: Avoid having snacks high in fat, salt or sugar easily at hand around the home, as this might mean you are more tempted by them. Try replacing these with healthier alternatives, for example by putting a bowl of fruit on the kitchen table or next to your computer at home or at work.
  • Plan ahead: Make a list of healthier snacks to buy before you go shopping. If you tend to have a mid-morning or mid-afternoon snack to fill a gap between meals, plan out healthier options you can have, such as a slice of wholegrain toast and peanut butter. Read our page on healthier snacking.


5. Choose sustainably sourced fish

Fish is a good source of protein, vitamins and minerals, and oily fish such as salmon, sardines and mackerel also contain omega-3 fats that are thought to be beneficial for heart health. Government advice in the UK is that we should eat at least two portions (140g each) of fish per week, one of which should be an oily fish.

Although the amount of fish we typically eat in the UK is about half this amount, demand for fish globally has more than doubled in the last 50 years. This huge increase in demand has meant that about a third of global fish stocks are now considered overfished. It is important that we ensure a more sustainable future for fish and other seafood by making more environmentally responsible choices when shopping. Here are a few tips:

  • Choose a wider variety of fish: There are a wide variety of seafood species available to buy in the UK, but we tend to buy only a small number, known as 'the big 5' (cod, haddock, tuna, salmon, and prawns). Try experimenting with other seafood species, for which stocks are thought to be more abundant, or those that are caught or farmed more responsibly, such as mussels, mackerel and European hake.
  • Check out the Marine Conservation Society Good Fish Guide or download the Good Fish Guide app to find more sustainable alternatives when shopping.
  • Look out for ecolabels on certified fish products: The blue Marine Stewardship Council (MSC) logo; the Soil Association (Organic) logo; Aquaculture Stewardship Council (ASC) certification; and RSPCA monitored logos (see below). These are certifications that provide assurance fish and seafood has come from more sustainable sources that set standards for managing stock levels and animal welfare.
A selection of sustainable logos found on food packaging

6. Waste less food

According to the Food and Agriculture Organisation (FAO) of the United Nations, around a third of the food that we produce globally is either lost in the supply chain or wasted by us as consumers. It has been estimated that food losses and waste contribute as much as 10% of greenhouse gases emissions. If food waste were a country, it would be the third largest emitter of greenhouse gases (behind China and the US). However, less than a third of us in the UK make a clear link between wasting food and climate change, even though 8 out of 10 of us are concerned about climate change as an issue. Reducing the amount of food that we waste is a key part of making our diets more sustainable, whatever type of diet we choose to eat.       

The good news is that, in the UK, we have reduced the amount of food we waste in recent years by 7% (between 2015 and 2018). While it may not sound like a lot, that is enough food waste to fill the Royal Albert Hall ten times! It is also estimated this has saved the UK public over £1 billion per year. So, finding ways to reduce food waste can help the environment and save you money – an obvious ‘win-win’. In 2021, the first ever UK Food Waste Action Week took place, aiming to raise awareness and promote activities that help reduce the amount of food wasted.

Below are some tips on ways to cut down on the amount of food you throw away:

  • Set your fridge to the correct temperature: The average fridge temperature in the UK is set at 7°C, which is higher than the recommended range of 0-5°C. This means that food is more likely to go off quickly - especially common items such as milk. Find out how to set your fridge correctly on the Love Food Hate Waste campaign website.
  • Know your date labels: Knowing the difference between ‘best before’ and ‘use by’ dates can help to prevent you wasting food. Foods that are past their best before date can still be safe to eat, but may not be of the same quality, while use by dates on food are about safety – food can be eaten until the use by date but not after. A lot of foods, including meat and milk, can be frozen before the use by date, so it is helpful to plan ahead. Find out more about date labels from the Food Standards Agency.
  • Store food correctly: Check food labels when you get your shopping home to help ensure food stays fresh for as long as possible. For more information on how to store many common food items read Love Food Hate Waste’s A-Z food storage guide.
  • Use your freezer: UK households waste 20 million slices of bread every day, but much of this waste could be prevented. Bread is one of many food items that are suitable for home freezing, and slices can be toasted straight from the freezer. This can be useful, especially if you have bought too much when shopping. Find out more information on freezing common foods from the Love Food Hate Waste website.
  • Plan your meals: Try to make a list before going shopping and only buy the items that you need. Choose foods with the longest ‘use by’ date if you are not sure when you will use them. If you cook more food than is needed when preparing a meal, see if you can portion this out and freeze it, giving you an easy meal for another time. Find a range of creative ideas for how to use leftover food on the Love Food Hate Waste website.

Did you know?

The equivalent of 3 million glasses of milk is poured down household sinks in the UK every single day! You can freeze milk at any time up until its ‘use by’ date in its original container or you can decant milk into ice cube trays if you only have a small amount left over. These can be used straight from the freezer when cooking, in dishes such as soups or sauces, or popped straight into a cup of tea.


Should I eat a 'plant-based' diet to be more sustainable?

The term ‘plant-based’ has become very popular in recent years and seems to be everywhere, but there appears to be confusion about what this really means. A survey of the British public conducted on behalf of the British Nutrition Foundation found that close to two-thirds of people thought that following a ‘plant-based’ diet meant being either vegetarian or vegan. However, aiming for a more ‘plant-based’ style of eating does not mean that we must cut out animal source foods completely from our diet.

The Eatwell Guide shows the amount of foods we should aim to eat from each of the food groups to achieve a healthy, varied diet (see above). The two largest groups in the Guide are ‘plant-based’ foods – the vegetables and fruit group, and the starchy foods group (e.g. pasta, rice, potatoes, breakfast cereals). Other plant-derived foods shown in the Eatwell Guide are pulses (beans, peas and lentils), nuts, and seeds. However, the Eatwell Guide also includes some lower-fat and lower-sugar dairy foods, as well as lean meat, eggs and fish, as part of an overall healthy diet. So, yes, we should all eat a diet rich in plants (and foods made from them) – for our health and for that of the planet - but this does not have to mean cutting out animal foods or becoming vegetarian or vegan. Research shows that a diet more in line with the Eatwell Guide is likely to have both environmental and health benefits, and so can help us to eat in a more sustainable way.


The UK government Eatwell Guide

What about meat and dairy foods?

The environmental impact of eating meat and dairy foods has attracted a lot of attention in the last few years. At a global level, farming livestock for meat, milk and eggs accounts for almost 15% of all greenhouse gases produced by human activities. This includes emissions released directly by animals (such as methane produced by cows), as well as emissions linked to producing animal feed, and for processing and transport of livestock products. It is generally agreed that meat and dairy products are associated with more greenhouse gas emissions and land use than other types of food. In particular, the meat from ruminants (cattle and sheep) has a higher environmental impact than chicken and pork because of the methane produced by ruminant animals as a part of their digestive processes. However, the environmental impact of meat and dairy can vary widely according to the type of farming practices used. For example, the greenhouse gas emissions for a kilogram of beef produced in the UK are about a third lower than the global average. So, it is important to distinguish between local and global figures where possible, when talking about the impact of animal products (as well as other food types) on the environment. 

Although meat and dairy products may score less well in terms of their environmental impact, these foods can make an important contribution to intakes of some essential vitamins and minerals. This is why they are included in the Eatwell Guide. For example, dairy foods provide about a third of UK adult intakes of calcium and iodine, on average, and meat is an important contributor to intakes of iron, zinc and selenium.

Studies tend to suggest that reducing our meat consumption in high-income countries, such as the UK, is needed to achieve a more sustainable dietary pattern. The suggested changes are less straightforward for dairy foods (such as milk), however, which may be because they are able to provide important nutrients at a lower environmental impact than for meat. Overall, research that has considered a range of factors, including nutrition, health, cost and cultural acceptability, shows that diets can include some meat and dairy foods while also having lower environmental impact.


Is a vegan diet better for my health and the planet?

Although interest in consuming vegan-friendly foods appears to be growing in the UK, only a small proportion of UK adults consider themselves to be completely vegetarian (4%) or vegan (1%).  Evidence suggests that a vegetarian or vegan diet can help to reduce the greenhouse gases and land use associated with our current diets but might not be as effective for reducing the amount of water that is needed. Studies show that vegetarian and vegan diets are associated with a lower risk of some diseases, such as heart disease, type 2 diabetes and cancer. However, this may be partly because vegetarians and vegans are healthier in other ways, such as drinking less alcohol or doing more exercise. It is also worth remembering that foods that are sold as ‘vegan’ or ‘plant-based’ are not automatically healthier. Some products or meals may contain a lot of saturated fat, sugar or salt, which we should all aim to limit in our diet. So, it is important to check the traffic light labels on the front of packs, and to choose those with more greens and ambers and fewer reds.

A well-planned and diverse vegetarian or vegan diet can readily provide most of the nutrients needed for good health. But there are a few nutrients that need particular attention if excluding animal source foods from the diet entirely, such as vitamin B12, iron, calcium and iodine. Vitamin B12 is not generally found naturally in plant foods, so it is important to have vitamin B12-fortified foods or vitamin B12 supplements if following a vegan diet. Some plant-based dairy alternatives, such as oat, soya and almond drinks, are now fortified with calcium and sometimes with other nutrients present in cows’ milk (such as iodine) but remember to check the label to see if products contain added vitamins or minerals.


Useful links for more information


Last reviewed June 2021. Next review due June 2024.

Healthier and more sustainable diets on a budget

Watch the video below to find out more about how to have a healthier and more sustainable diet on a budget.

Healthier and more sustainable diets on a budget

Hannah Molloy, Junior Nutritionist

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