Nutrition that’s kind to the planet is also a winner for healthy weight

Professor Jaacks, a distinguished academic nutritionist based in Edinburgh, reminded us that CO2 may be warming the planet but methane and nitrogen dioxide, two other copious by-products of agricultural production connected with animals and fertilisers were even worse for the climate, molecule-for-molecule. Whilst all other sources of climate-damaging gases were projected to decline over the next decades, agriculture and aviation are due to become the top emitters, pumping out the same level or more by 2050, despite a hoped-for 50% drop in that agricultural contribution derived from meat and animal products. Food produced in the UK might account for 11% of emissions, but that share rises to 35% if we factor in imports. We also waste a staggering 20% of food, not so much from over-supply, but junked especially after consumers buy it. For the planet, buying too much is just as damaging whether we eat too much or throw it away.

Worldwide, the portion of emissions attributable to meat and ruminant food production is around 50%; after that comes deforestation (11%) to create more growing space - for palm oil, coffee, tea and similar crops. Both of these sources put transport (food chain miles) and travel (consumer miles in trips to the shops) in the shade – their contribution totals 7%. So the pointers for priority action are not perhaps the familiar targets – fewer lorries and supermarkets shops would help, but the inducements of retailers to buy more than we need, and demands and disposal habits of consumers, cause the greatest impact. And composting or recycling the food we waste doesn’t compensate for the impact of over-buying in the first place.

What about eating local produce? – that would be good if it was more plant-based, but meat and dairy produce predominates, especially in Scotland. We could never look to UK farmers to feed us year-round in a sustainable way. A shift to buying local would achieve a drop in emissions, but only as much as one day per week of a vegetarian diet. We need to look elsewhere for cultural habits to change.

What is best for the planet and for our dietary health? In Professor Jaacks’ view, what is sustainable is a long way from where we currently are, and further than the current public debate we have been having on health balanced diets, cutting fat, sugar, salt and so on. One point she added was that we have to recognise that ultra-processed foods, which are increasingly linked to obesity, are attractive to consumers in a sustainable world as their shelf-life is longer than fresh produce. But they tend neither to be healthy nor sustainable as options. She also underlined that achieving major change has got to focus on the domestic consumer; eating out unbalances the diet but a sustainable future has to start at home and the everyday shop.

Professor Jaacks proposes a ‘plant-forward’ diet*, a varied blend of predominantly fruit, vegetables, nuts and wholegrains, also potatoes. Cut portions, and cut waste, so offer (if you are a retailer) and buy (if you are a consumer) an awful lot less to eat. And cut down too on meat and dairy, hotter-country crops such as palm oil, coffee and tea; pasta and pizzas made from refined grains.
The proposal for a sustainable diet gained many additional mentions from other speakers at the conference, as a key plank in any plan to tackle climate change.

These proposals are very much along the lines of a healthy diet with which we are familiar, but only in theory. How do we translate what’s good for human health and the planet into everyday shopping, helped by retailers that want to keep their customers well for the longer-term? Now that’s a challenge – a lot of OAS’s work offers practical groundwork, pointing us in the right direction. Being a key partner in the Scottish Food Coalition enables aligning of these ambitions. Let’s get broader acceptance for that vision, and build the will for change. But we don’t have time on our side – the prevailing climate of the conference was of urgency, and frustration with setbacks to progress.

Plant-forward diet *

What is a plant-based diet and why should you try it? - Harvard Health Katherine D. McManus
‘It doesn’t mean that you are vegetarian or vegan and never eat meat or dairy. Rather, you are proportionately choosing more of your foods from plant sources.’

Professor Jaacks is a distinguished nutritionist at the Global Academy of Agriculture and Food Systems at the University of Edinburgh; she works with a team of colleague nutritionists and a cross-disciplinary set of academics to solve complex problems along the food chain, including law, policy and markets.

Blog written by Dr Andrew Fraser, Chairperson at Obesity Action Scotland, and Dr Daphne Varveris, Obesity Action Scotland Steering Group Member and Consultant Anaesthetist NHS Greater Glasgow and Clyde