“We are destroying civilisation; our food system has to change; and solutions do exist.” This is the message from renowned epidemiologist Walter Willett (Harvard Medical School), who gave us an interview.
Who is Walter Willett?
Walter C. Willett is Professor of Epidemiology and Nutrition at the Harvard T.H. Chan School of Public Health and Professor of Medicine at Harvard Medical School, Boston. He has conducted research on the link between diet and health for over 40 years and has over 1,700 scientific publications to his name. He co-chaired the EAT-Lancet Commission, which developed the planetary health plate capable of feeding the world’s 10 billion people by 2050.
Why are we talking about a food transition today and what are the challenges involved?
W.W. “In many countries, we are seeing a nutritional crisis due to an obesity epidemic that shows no sign of abating. At the same time, we are in the process of destroying civilisation as we know it due to climate change, and our food system is a significant contributor to this.”
In what ways is a more plant-based diet beneficial?
W.W. “There are significant health advantages to adopting a diet mainly based on healthy plant-based food, without necessarily being strictly vegan. Such a diet is richer in nutrients, healthy fats and phytochemicals than current Western diets, while limiting saturated fats and cholesterol. Such a ‘flexitarian’ or ‘plant-based’ diet would have major benefits for the planet in terms of reduced greenhouse gas emissions, land use and pollution. It cannot solve the problem of climate change by itself, but it is an essential element in avoiding disastrous global warming.”
Which nutrients were considered in the EAT-Lancet plate for feeding the world by 2050? Are there any nutrients that are more problematic?
W.W. “We considered all types of nutrients, and the EAT-Lancet Plate is nutritionally healthy. The plate includes around two portions of animal-based foods; if you decide to reduce your intake of these foods, it will be important to get enough vitamin B-12 through supplements or fortified foods.”
In concrete terms, which foods should we eat more or less of?
W.W. “Compared to current intakes in almost all countries, we need to eat more fruit, vegetables, whole grains, nuts, pulses, soy-based foods and fish. In high-income countries, we have to eat less red meat, poultry and, in some cases, eggs. In some parts of the world, consumption of these foods is already at or below our targets, so no reduction is needed.”
Can the planetary plate be achieved? What are the conditions for achieving this objective?
W.W. “It is a realistic goal; this dietary model is in line with the traditional Mediterranean diet and the traditional diets of many regions of the world. It can be made up of foods and flavours from almost any country. However, much remains to be done to achieve this, including widespread education and awareness raising, and policies that make this diet affordable and accessible to all.”
Do you have any advice on how to easily plan this diet?
W.W. “A simple way to plan this diet is to think 1 + 1 for animal protein: about one portion of dairy products per day and one portion per day of other animal-based foods (including red meat once a week). Add to this, nuts, pulses and soy foods, plenty of fruit and vegetables, whole grains and healthy fats. It’s quite simple, and it offers a wide variety of wonderful flavours. This way of eating has to become a new standard, because it is good for our health and for the health of the planet… and it can be enjoyable.”