There is a very close link between diet and health — a link that also encompasses the health of the planet. The latest research now tells us this, and so do the pyramids.
To help everyone understand how much what we eat affects our health, it is important to make accessible what research has been telling us for several decades.
American nutritionists, led by Ancel Keys, realised as far back as the 1970s that the Mediterranean diet was good for you. But how could all that body of research, studies and epidemiological surveys be summarised in a readable and useful way?
The food pyramid is the most brilliant, simple and effective representation of a correct and balanced dietary lifestyle — one that coincides with the Mediterranean dietary model identified in the 1970s by Ancel Keys, at the conclusion of a wide-ranging study on the correlation between nutrition and mortality. It was the United States Department of Agriculture (USDA) that devised this scheme in 1992, placing foods to be eaten only occasionally at the apex and fundamental foods — those proven to have a positive effect on health, and therefore to be eaten every day — at the base. The aim — which was achieved — was to summarise the principles of the Mediterranean diet in a simple, clear and comprehensible graphic scheme.
Foods are divided into horizontal bands. Moving progressively from the base towards the apex, the recommended frequency of consumption for each food category decreases. At the base of the pyramid sit fruit and vegetables, typical of Mediterranean eating habits and rich in nutrients (vitamins, mineral salts, water) and protective substances (fibre and bioactive compounds of plant origin). Moving up the pyramid, one finds foods of increasing energy density — very heavily, indeed too heavily, present in the North American diet — which should be eaten in ever smaller quantities.
In 2005 the scheme was revised and updated with significant changes, including the distinction between healthy and unhealthy fats and the repositioning of red meat towards the least advisable foods. Yet, years on, the food pyramid based on the Mediterranean diet remains a reference model, one in which all the principal nutritional recommendations issued across the most diverse fields of medicine converge.
The impact of nutrition on health is a well-established concept in medicine and underpins prevention for many different conditions. In parallel, the study of diet is undergoing an expansion that extends from the strictly nutritional sphere into other areas of culture and science, including the social sciences, economics and — most interestingly — environmental sciences. A new awareness is emerging today: the dietary choices of individuals and communities have considerable repercussions for each of us, for society and for the environment, and can concretely influence the future of humanity on the planet.
A new and extremely useful tool for providing fresh motivation and steering people towards sound nutritional choices has been given to us by the Barilla Center for Food and Nutrition (Bcfn).
The approach that combines environmental awareness with consideration of the use of natural resources to obtain nutrients was inaugurated in June 2010, when experts gathered and summarised the first studies on the ecological impact of various foods.
By arranging them in descending order, researchers discovered that the categories of foods at the top of the Mediterranean food pyramid — that is, the least advisable ones — almost perfectly coincide with those that are most energy-intensive and harmful to the environment. The first edition of the double pyramid drew on 140 data points from 35 scientific sources; the latest edition (2015) drew on 1,222 data points from 385 sources. Today, the majority (71%) of the bibliographic sources used relate to the Carbon Footprint, followed by the Water Footprint and the Ecological Footprint. This is due to a combination of factors. The first is certainly the fact that the Carbon Footprint is the most widely used indicator among researchers and, above all, the one for which the most established and scientifically recognised calculation standards exist. The three environmental indicators, expressed per kilogram (or per litre) of food, were calculated as the arithmetic mean of the values made available by the research.
Carbon Footprint: represents the total greenhouse gases responsible for climate change caused directly or indirectly by human activities. It is measured in mass of CO2 equivalent.
Water Footprint: quantifies the consumption and patterns of use of water resources. It is measured in volume (litres) of fresh water consumed, evaporated or polluted during a product's lifecycle, and also takes into account the location where the water was abstracted.
Ecological Footprint: measures the area of biologically productive land required to produce the resources consumed by a household, a country or a single production process, and to absorb the related CO2 emissions. This index — expressed in square metres or global hectares — is standardised at an international level and is used, for example, by the European Commission to measure resource consumption at national level. It calculates the quantity of biologically productive land (or sea) needed to supply the resources and absorb the emissions associated with a production system.
By placing the food pyramid alongside the environmental pyramid, a correlation of considerable interest has emerged, capable of conveying a remarkable message: the foods for which greater consumption is recommended are generally also those that generate the smallest environmental impacts.
The importance of diet for health is now confirmed daily by new studies. Research in recent years has shown that the agri-food sector is one of the areas most responsible for greenhouse gas emissions and water consumption. The novelty communicated by the Barilla Center Food Nutrition's double pyramid is that the foods nutritionists recommend consuming most frequently are also those with the lowest environmental impact.
Conversely, the foods whose consumption is recommended to be kept low also have a greater impact on the environment.
In other words, this model merges the two fundamental objectives of protecting health and the environment into one.
It is truly interesting to discover the almost perfect correspondence between foods that are harmful to health, in the red band, and those that are harmful to the planet's ecological balance, and the parallel symmetry of foods that are beneficial to health, which are also the lightest on the environment.
The elaboration of the ecological footprint of foods was carried out using the life cycle analysis approach (Life Cycle Assessment, Lca), a methodology that consists in evaluating the energy and environmental burden associated with all its production phases. In the case of a food, this spans from the cultivation of raw materials through to distribution and any cooking, canning or refrigeration.
All of this confirms, on the basis of hundreds of studies, that the dietary choices of individuals and communities have considerable repercussions both on the individual and on society and the environment. Personal wellbeing and dietary choices are, in this model, integrated components of the global health of the ecosystem.
The proposition of the double food – nutritional pyramid updates and extends the original value and significance of Ancel Keys's food pyramid alone. The cultural and scientific implications of the new model have very broad potential, ranging from multidisciplinary research to the possibility of a daily application of the key message: the diet that is healthiest for the person is also the most sustainable for the planet.