Why you should eat a plant-based diet, but that doesn't mean being a vegetarian

Plant-based diets are often shown to be good for health. Yet Australians eat a lot of meat and are sometimes reluctant to completely cut meat from their diet. So it’s important to know that eating a plant-based diet doesn’t have to mean becoming a vegetarian.

Plant-based diets are high in vegetables, wholegrain bread and cereals, legumes and whole fruits, yet can still contain small amounts of lean meats and reduced-fat dairy products.

A survey of Australians found most (70%) thought a plant-based diet would prevent disease. But what does the literature say? And is meat really bad for you?

Health benefits of plants

Plants are rich sources of many nutrients that are important for good health, including unsaturated fats, vitamins (such as folate), minerals (such as potassium), fibre and protein.

Eating a plant-based diet has been linked to lower risk of obesity and many chronic diseases, such as heart disease, type 2 diabetes, inflammation and cancer.

A recent study that followed more than 200,000 US adults for more than 20 years found that eating a diet high in plant foods and low in animal foods was associated with a 20% lower risk of diabetes compared with individuals eating a diet low in plant foods.

Well known variations to plant-based diets include the Mediterranean diet and the Dietary Approaches to Stop Hypertension. These dietary approaches are known as dietary patterns as they focus on the overall diet rather than single foods. Rich in vegetables, fruits, legumes and reduced-fat dairy products, these dietary patterns have been linked to lower risk of obesity and chronic disease.

Is the processing of plant foods important?

Processing can remove many of the nutritious benefits of plant foods and can often result in the addition of salt and sugar. For example, whole foods, such as an orange and wholemeal bread, retain more beneficial fibre than processed alternatives, such as fruit juice and white bread.

But not all processing is necessarily bad. For example, frozen and canned vegetables can be useful additions to the diet, just check the labels to see what has been added during processing.

Is meat bad for you?

Meat is a rich source of beneficial nutrients, such as protein, B vitamins, iron and zinc. But red meat can also contain high amounts of saturated fat and processed meats can be high in sodium.

Eating red and processed meats, such as burgers and hotdogs, has been linked to higher risk of cancer, heart disease and death. In contrast, white meat intake, such as chicken and fish, has been linked to lower risk.

Cancer: Evidence is convincing for a link between red and processed meat and colorectal cancer. A review of available evidence, known as a meta-analysis, showed that colorectal cancer risk was 14% higher for every 100g of red and processed meat (about a large beef steak) eaten per day.

Heart disease and type 2 diabetes: Evidence mostly points towards higher risk of heart disease and type 2 diabetes with higher processed meat intake.

A meta-analysis showed that each 50g daily serving of processed meat (about one to two slices of deli meats or one hot dog) was linked with a 42% higher risk of heart disease and a 19% higher risk of type 2 diabetes. But, eating unprocessed red meat was not associated with risk of developing heart disease or diabetes.

Early death: Evidence generally points towards higher risk of death with higher red and processed meat intake. A recent study that followed more than 500,000 US adults over 16 years showed that risk of all-cause death was 26% higher with greater processed and unprocessed red meat intake. When red meat was substituted for unprocessed white meat, risk of all-cause death was 25% lower.

What should we be eating?

Eating a variety of unprocessed fruits, vegetables, wholegrains and legumes is key when it comes to maintaining a healthy, balanced diet.

Although high intakes of red and processed meats may increase risk of major diseases, a healthy, balanced, plant-based diet can still include small amounts of lean meat trimmed of visible fat (particularly unprocessed white meat) and reduced-fat dairy products.

Eating a plant-based diet is in line with the Australian Dietary Guidelines to promote health and well-being.

Australians are recommended to eat a wide variety of foods from the five core food groups (fruit, vegetables, cereals, lean meat and/or their alternatives and reduced-fat dairy products and/or their alternatives), to choose lean, reduced-fat meats and dairy products and to limit processed meats.

Top five tips for achieving a plant-based diet:

• try some meat-free meals each week - include alternatives such as eggs, beans and tofu.
• replace some of the meat with legumes - for example only add half the amount of beef and top up with chickpeas.
• choose wholegrain cereals more often than white varieties - such as wholemeal bread and pasta.
• eat a variety of colours of fresh vegetables and fruits and buy fresh produce in season.
• canned and frozen vegetables are nutritious too - choose options low in salt and sugar.

Katherine Livingstone receives funding from the Alfred Deakin Postdoctoral Research Fellowship.