Research has shown that the Mediterranean diet, which is having a bit of a revival lately, is actually also one of the best sustainable diets.
After that mad dash to bring together a storybook Christmas dinner, you might be wondering why so much food went to waste once again this year. There are only so many ways you can refashion leftover turkey, ham and most of the salads and vegies that probably ended up in the bin. ‘Special occasion’ food industry marketing – for Christmas, Easter, Australia Day and just about any long weekend – has us storming the supermarkets to buy up big, as though we were heading for some sort of natural disaster or famine. And many, many restaurants continue to dish up single-serve courses that could easily feed two or three diners. In all that noise and all the complex playing to our insecurities and aspirations that is the mainstay of food marketing – very few of us stop to think how food waste is linked to the environment. We worry about the impact of which electricity supplier we choose or which car will be most fuel-efficient in an attempt to reduce our carbon and water footprint, but we fail to realise that the food we choose to eat and the food we waste often have a much larger impact on our environment. The Food and Agricultural Organisation (FAO) reports that carbon emissions from food, not consumed and thrown out, amount to 3,300 million tonnes of greenhouse gas per year. That equals the annual emissions from every country on this planet except China and the USA. The Australian National Waste Report of 2010 showed that each Australian generates about 361kg of food waste a year per person. The average household wastes about $616 worth of food a year. And when you consider the costs further along the food chain, you remember it is not just the food itself that is wasted, but all the resources and energy that go into growing, transporting, processing and preparing that food. In 2013, the National Health and Medical Research Council released the revised and updated Australian Dietary Guidelines, which is a tool that can be used by the public to guide them in reducing the risk of developing chronic health conditions such as obesity, cardiovascular disease and cancer. However these guidelines provided no advice to the public on how to make healthy and sustainable choices. We are not alone. The latest Dietary Guidelines for the US also don’t address sustainable eating along with healthy eating. To date, only the Nordic countries and Brazil have addressed the impact of food choice on the environment in their national dietary guidelines.
Environmentally-conscious dietary changes
Research has shown that the Mediterranean diet, which is having a bit of a revival lately, is actually also one of the best sustainable diets. Characterised by a very low intake of red meat, moderate intake of white meat (chicken and fish) with a high intake of beans and legumes it is lighter on our environment. If more of us made just one change in our diet towards the Mediterranean diet model the savings to the environment would be considerable. Switching the type of meat you consume, from beef to pork, will reduce emissions of greenhouse gases (carbon dioxide, nitrous oxide and methane) from 30kg to 9.3kg CO2 per kilogram of food. Further reductions can be made if beef is swapped for soybeans, reducing emissions from 30kg to 0.92kg CO2 equivalents/kg of food – and there is the added nutritional benefit of beans being high in fibre, antioxidants and other phytonutrients. Even if you cannot bear to give up meat, cutting down to a few serves a week will make a difference. Worldwide campaigns like Veganuary and Meat Free Monday encourage people to not consume meat and replace it with beans and legumes. The important question is: can healthy eating also be sustainable? How do we make the right diet choices for our health and the health of the planet? The consumption of fish for the omega-3 fatty acids is widely recommended for heart, joint and brain health, but we must consider the impact on fish stocks too, which are increasingly limited. Along with Katie Wood and Dr Beverly Muhlhausler, University of Adelaide, the University of South Australia (UniSA) has been investigating the fat composition of background diets. Diets that are monounsaturated-based (using macadamia oil or olive oil) seem to allow a greater absorption of the omega-3 fats that are naturally in our diet. Therefore making a simple change to the types of oils we use can have an impact on our total omega-3 levels in our bodies, while reducing our reliance on fish.
Modelling better food sourcing
A group led by Dr James Ward from UniSA’s School of Natural and Built Environments is using optimisation modelling (called linear programming) to select the best range of foods to achieve a particular objective, while delivering a nutritionally balanced diet. The objectives range from minimising the overall land footprint (where we find the model tends to select diets with less meat) to reducing the amount of irrigation (which accounts for 70 percent of the world’s freshwater withdrawals). The model can be used to evaluate tradeoffs between different objectives, such as selecting foods that are water-effi cient versus those that are land-efficient. The same optimisation model has also been applied to urban agriculture, to fi nd the optimal blend of backyard crops to give the greatest impact on self-suffi ciency or dietary cost savings. Love Food Hate Waste has a website which provides tips and ideas about how to reduce food waste, as well as a serving-size calculator for organising food for functions, be it at home or the workplace. One tip I can share for more sustainable dining out is to consider choosing an entrée instead of a main course. You will often find it is just enough, and when I am with friends and we are sharing food, we order one less dish, reducing both food waste and the chance of extra centimetres on our waistlines. Dr Evangeline Mantzioris is an Accredited Practising Dietitian and Lecturer in the Bachelor of Nutrition and Food Science Program at the University of South Australia. Dr. Mantzioris will be particpating in a WOMADelaide Planet Talks workshop (How Sustainable is Your Diet?) on Saturday, March 7 at 12pm. For more information about the Planet Talks and the workshops visit unisa.edu.au/womad