Plant-based eating

Not all plant-based diets are equal: the focus should be on “healthy” plant foods. Dr Frank Hu and colleagues (Harvard School of Public Health) developed a plant-based diet index (PDI), using data from the prospective Nurses’ Health Study and Nurses’ Health Study II which examined the impact of diet, among other factors, on disease outcomes.(1) They assigned scores to plant foods based on their healthfulness:

1. A healthful PDI (hPDI) was allocated to whole grains, fruits, vegetables, nuts, soya, legumes and vegetable oils

2. An unhealthful PDI (uPDI), was allocated to sweetened soft drinks, refined grains, confectionary etc.

The team demonstrated that diets scoring highly for hPDI were more strongly associated with lower CHD risk, while diets with a high uPDI score were associated with an increased risk of CHD. This study highlights the consequences of over-generalising food patterns in research: it may downplay the benefits of diets centred on whole plant-based foods, while simultaneously providing false reassurance of health benefits to those following unhealthy plant-based diets.

There is a large body of evidence to demonstrate that the widespread adoption of healthy, plant-based diets with reduced amounts of animal-based products is linked to:

• Improved nutrient status. In particular, plant-based diets tend to be higher in fibre and lower in saturated fat and added sugars.(3-6)

• Improved weight management

• Cardiometabolic health

  • Cardiovascular(7-10)

  • Diabetes(11-13)

  • Hypertension(14,15)

  • Hypercholesterolemia(16-18)

Studies indicate that widespread adoption of a plant-based diet could prevent 8.1 million deaths every year as a result of reducing meat intake, increasing fruit and vegetable consumption and balancing energy intake to reduce obesity.(11)

High adherence to the EAT Lancet Planetary Health Diet, a plant-based diet with reduced amounts of animal proteins, is associated with 25% lower all-cause mortality, 24% lower cancer mortality and 32% cardiovascular mortality(3) Research from the American Heart Association also confirms that as healthful plant-based foods in the diet increase, cardiovascular disease decreases.(8)

As well as a reduction in animal-based products, the wide variety of nutrients found in plant-based foods are also thought to contribute to the health benefits associated with more plant-based eating.

Plant-based foods are typically:

• Lower in saturated fat

• Do not contain cholesterol

• Higher in heart-healthy unsaturated fats

• Higher in soluble and insoluble fibre

• High in micro-nutrients (vitamins, minerals, antioxidants)

More on plant-based eating and health:

• Plant-based eating and cardiometabolic health

• Plant-based eating and diabetes

• Plant-based eating and cholesterol

• Plant-based eating and healthy ageing

• Plant-based eating and non-alcoholic fatty liver disease

In addition to the health benefits of plant-based eating, there is an increasing body of evidence that confirms that dietary patterns with plant-based foods at the core have lower environmental impacts.(2,7)

Today our food systems are responsible for 34% of global greenhouse gas emissions (GHGe)(19) and 50% of habitable land use.

Despite only providing 37% of protein and 18% of the energy requirements, over half of GHGe and 83% of land is associated with producing animal-based foods.(20)

This includes livestock farming, producing animal feed and conversion of natural carbon sinks (forests and grasslands) into land for animal agriculture.

According to current research, a plant-based diet with lower amounts of animal-based foods is consistently associated with a lower environmental footprint.

Diets which reduce, but do not necessarily exclude, animal products offer environmental benefits including:

• Up to 70% lower carbon footprint(2,5,7,20,21)

• Up to 80% less land use(7,20)

• Up to 50% less freshwater consumption(7,20)

• Preservation of biodiversity(2)

• Improved nitrogen (N) and phosphorous (P) balance(2,22-24)

• Halved eutrophication and acidification of oceans(20)

More on plant-based eating and the environment

• Plant-based eating and environmental footprint

• Sustainable Diets for Better Human and Planetary Health

• EAT Lancet’s Planetary Health Diets: Plant-based food as part of the solution

• Reversing the nitrogen crisis

• Which dietary changes are critical to reduce our environmental burden?

• Sustainable dietary guidelines

  Many national food-based dietary guidelines if adhered to, can significantly reduce our environmental burden.

Important to note is that a more sustainable diet is not only achieved with a vegan eating pattern. Consuming more healthful plant foods and reducing intakes of animal products can bring about significant improvements for human and planet health.

Variety is key

• Use as many different types of grains, nuts, seeds, fruit and vegetables as they all provide different essential nutrients

• Fruit and vegetables. Think rainbow colours and always include red/orange, yellow and green

Partly or fully replace meat with healthy plant proteins and vegetables

• Reduce the quantity of meat in your favourite recipes

• Use plant proteins e.g., soya mince, tofu, beans, lentils & nuts and vegetables to bulk up meals

• If you do have meat, watch your portions, choose better quality and remove all visible fat

Mix it up and go 50/50 dairy and plant-based alternatives

• Start incorporating plant-based drinks and/or alternatives to yogurt as part of your daily repertoire. Varieties include soya, almond and oat

• Choose those fortified with calcium and vitamin B12

• Use in cooking, on your cereal, to make smoothies and in tea and coffee as you would use dairy

• Cheese: whether plant-based or dairy, cheese should be kept to a minimum as the majority are rich in saturated fat

More seasonal and local fruit and vegetables - avoid air-freight

• Avoid out of season local products which are most likely grown using heated greenhouses

• If out of season, choose frozen, canned or dried varieties – they’re as nutritious for you

• Keep it colourful: ensure you include, red/orange, yellow and green varieties

• We all need to eat more fruit and vegetables – ensure you include with every meal and snack

Go wholegrain wherever possible

• Wholegrains help to boost fibre intakes, fill you up quicker and provide essential minerals

Reduce food waste

• Did you know we throw away 30% of all food we buy? Not good for your finances or the environment. Fruit and vegetables are by far the most wasted food

Plan & shop smart

• Planning meals for the week and generating a shopping list will not only help reduce waste but could save money

• Buy fresh products especially fruit and vegetables with a short shelf-life in the exact quantities you need

• Make use of canned or frozen fruit and vegetables – they’re just as good as fresh

Food preparation

Preparing or cooking too much food accounts for over a quarter of food waste costs. Using leftovers saves you money and the planet

• Only prepare and cook the exact quantity of food you need – check portion guides

• If you do have leftover ingredients – freeze or use creatively e.g.,

  • Unused vegetables can be used to make soups or roasted and used as a side dish or in salads

  • Excess fruit can be made into smoothies, jams, chutneys, fruit crumbles or other desserts