'˜We need an eco-friendly diet '“ but perhaps not with insects'

Cutting back on meat would help reduce carbon emissions, but other dietary factors '“ like health, affordability and cultural acceptability '“ are important too, writes Jennie Macdiarmid.

Insects have been suggested as an alternative to meat but people may have to be persuaded to eat them

Historically, the focus on how we reduce greenhouse gases has been on the energy sector, rather than the food we eat.

But changing our diet now has to be one of the priority areas for cutting emissions. Action across the food and agricultural sector has predominantly been around finding technological solutions and ways to decrease food waste.

Studies, however, have shown that technological solutions alone will not be sufficient to meet our targets. Adopting “low greenhouse-gas-emissions intensive foods” and changing diets to those that are “less resource-intense” are some of the mitigation actions proposed in the most recent report by the Intergovernmental Panel on Climate Change (IPCC).

The most greenhouse-gas-intensive foods are animal products because of the high emissions associated with livestock production. Scottish Government-funded research is being carried out by the Scottish Environment, Food and Agriculture Research Instiutes (Sefari) and others to find ways to reduce emissions in livestock production, including huge innovations in livestock management, breeding and on disease control.

Nevertheless, this does not get away from the need to look at our meat consumption. Interestingly, a number of countries, including the Netherlands, Sweden and Brazil, have revised their dietary guidelines to incorporate advice on reducing the environmental impact of diets – ie by reducing meat consumption.

It is understandable that this may be an unpalatable option for many in society – it has economic implications and goes against the tradition of having meat in the diet, as explored by Quality Meat Scotland, the National Farmers Union Scotland, and the National Sheep Association in their written submissions to a Climate Change Bill that will be discussed today by the Environment, Climate Change and Land Reform Committee.

Quality Meat Scotland states: “It is far too easy to forget that agriculture is about food production and that food production is a non-discretionary activity. It is also important to recognise the role of food production in sustaining employment in rural areas, and its contribution to the wider Scottish economy and balance of trade.

“The risk of landscape degradation that would accompany the end, or even the substantial reduction, of livestock production in Scotland similarly cannot be ignored.”

Knowing the environmental pressures and health implications, however, does not seem to be sufficient to convince a lot of people to eat less meat. Many people simply enjoy eating meat, but some also have a wider concern about the impact of eating less meat on their health, namely whether they would have enough protein in their diet. But empirical evidence shows there would not be insufficient protein in the diet as a result of eating less meat. Therefore, is there a misconception among the public and others about the need to find protein replacements for meat, whether plant-based foods or novel foods such as insects and laboratory-produced meat?

The fact is that people in the UK, including vegetarians, consume significantly more protein than they need. A recent study showed the quantity of protein available to eat in the UK is about double the amount required to meet the population’s dietary requirements, and even if all meat were removed the supply would still be about 120 per cent of requirements. This suggests that protein is the wrong nutrient on which to focus in terms of shifting to healthy and climate-friendly diets. In the UK, many people do not eat sufficient fibre and, therefore, replacing meat with plant-based and wholegrain foods would be beneficial for health as well as reducing emissions. Meat is a good source of iron and zinc and although these are also found in plant-based foods, should more attention be paid to these nutrients?

The proposal to eat insects as an alternative to meat is an interesting example of where this option has been considered from a narrow perspective. Insects have been described as a convenient, sustainable, economic and healthy alternative source of protein. While the impact of scaling up to commercialisation of insect production sounds to some like a viable alternative to livestock production, little is known about how much this would really reduce emissions since it would depend on the production system and the amount needed to feed the population. More importantly, insects are bio-accumulators and, depending on what they are fed, they can accumulate a range of heavy metals and contaminants, such as cadmium, lead and arsenic. The quantity in which insects would need to be eaten questions the health impact of potentially ingesting such toxins. People would also need to be persuaded to eat them. Any alternative needs to be looked at from multiple perspectives.

What we choose to eat can have multiple consequences and therefore there is the risk of unintended consequences if action is taken with only one driver in mind. A simple climate-compliant diet would miss all the other aspects of sustainable diets, such as health, affordability, accessibility, social and cultural acceptability and other environmental impacts (such as land use, water, biodiversity).

If the sole aim was to reduce emissions then a diet with energy intake predominantly from sugar would be effective since, relative to other commodities, its production has lower emissions. This may be acceptable to some people, but it is not something recommended for a healthy lifestyle. It is true that a healthy diet can be a low greenhouse-gas diet, but equally it could have high emissions. or a climate-friendly diet could be unhealthy.

So, there is no doubt that diets need to change but this can only be achieved if a holistic approach is taken. No one denies this will be challenging, especially reducing meat consumption, but doing nothing to change dietary intakes is not an option if our ambitious targets for reducing emissions are to be met.

Jennie Macdiarmid is a professor in sustainable nutrition and health at Aberdeen University