The Planetary Health Diet (PHD) is a global reference diet rooted in the best available science. It is a dietary pattern that aims to support optimal health outcomes while being adaptable to different populations and contexts worldwide, respecting cultural and regional variations. This flexitarian diet, rich in plants, emphasizes whole grains, fruits, vegetables, nuts, and legumes, with moderate to small amounts of fish, dairy, and meat.
Understanding the Planetary Health Diet
The Planetary Health Diet (PHD) is more than just a personal dietary choice; it addresses the global consequences of our food systems. The PHD is based on the direct effects of different diets on human health. Today's food systems are failing, with millions facing hunger and others suffering from preventable chronic diseases. Food production contributes to environmental degradation and deepens inequality, whereas it could be a source of environmental regeneration and justice.
The EAT-Lancet Commission's approach promotes a shift in consumption and production patterns, making healthy and sustainable food more accessible and reducing pressure on planetary boundaries. Transforming food systems requires cooperation across sectors, cultures, and regions. The planetary health diet includes a wide range of whole foods and cooking traditions.
Core Components of the PHD
The PHD is largely a plant-based diet consisting of vegetables, fruits, whole grains, legumes, nuts, and unsaturated oils such as olive, soybean, canola, sunflower, and peanut oil.
To illustrate how this might look on a day-to-day basis, the PHD sets out a reference diet as follows:
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Protein:
- Nuts (50g/0-27g)
- Beans, chickpeas, lentils etc (75g/0-100g)
- Fish (28g/0-100g)
- Eggs (13g/0-25g)
- Red meat i.e. beef, lamb, pork (14g/0-28g)
- Poultry (29g/0-58g)
- Dairy (250g/0-500g)
Carbohydrates:
- Wholegrains i.e. rice, wheat, oats (232g)
- Starchy vegetables i.e. potatoes (50g/0-100g)
- Vegetables (300g, equivalent to 3-4 portions/200-600g)
- Fruit (200g, equivalent to 2.5 portions/100-300g)
- Added sugars (31g/0-31g)
Fats:
- Unsaturated (40g/20-80g)
- Saturated (11.8g/0-11.8g)
In real terms, this means one might enjoy one beef burger and two servings of fish per week, with the remainder of protein coming from beans, pulses, and nuts. A glass of milk or some cheese or butter each day and just under two eggs per week could also be included.
Approximately half of a PHD plate would be covered with vegetables and fruit of different colors; a third made up of wholegrains, followed by plant proteins (beans, pulses), some unsaturated oils with optional but modest amounts of animal protein and dairy and some added sugars and starchy vegetables.
Health Benefits of the PHD
Adopting a predominantly plant-based diet has been, and continues to be, a well-trodden path, but the PHD is the first study to attempt to formulate a dietary plan that combines the benefits of such a diet for the environment in tandem with human health. The Commission claimed the potential benefits included preventing approximately 11 million deaths each year, caused by diet-related disease.
A 2024 review of 28 studies found that the PHD was significantly associated with lower rates of diabetes, cardiovascular disease, cancer and all-cause mortality. People who follow this PHD have a lower risk of every major cause of death, including cancer, heart disease, and lung disease, according to a recent study by Harvard Chan School researchers.
Environmental Impact
The PHD also addresses the environmental impact of food production. Today, a third of greenhouse gas emissions come from the global food system, and taming the climate crisis is impossible without changing how the world eats, the researchers said. Food production is also the biggest cause of the destruction of wildlife and forests and the pollution of water.
The planetary health diet (PHD) sets out how the world can simultaneously improve the health of people and the planet, and provide enough food for an expected global population of 9.6 billion people by 2050. Combined with improved agricultural production practices and a 50% reduction in food waste and loss, the Commission estimated that this diet would provide healthy nutrition to 10 billion people, the projected population of the Earth in 2050, and be environmentally sustainable.
Adoption of a plant-rich “planetary health diet” could prevent 40,000 early deaths a day across the world, according to a landmark report. The diet - which allows moderate meat consumption - and related measures would also slash the food-related emissions driving global heating by half by 2050.
Criticisms and Considerations
The PHD has faced criticism, with some industry experts suggesting the findings are based on outdated research. An example being the limitations on the consumption of saturated fats, which appear to lie at the crux of the health recommendations to reduce red meat, eggs and dairy.
Some studies found that a PHD could be deficient in certain micronutrients. The deficits in question include levels of vitamin B12 as well as retinol, vitamin D and calcium. In response, the Commission claims the PHD is an omnivore diet with approximately two servings of animal-sourced protein per day and they acknowledge that levels of vitamin B12 may need to be supplemented or fortified foods included.
Another important aspect of a healthy diet involves eating food sources of essential fatty acids (omega-3 and omega-6) in optimal balance. The higher levels of plant oils combined with low levels of fish in the PHD is more likely to suggest an unhealthy omega-6 to omega-3 ratio.
In response to these and other criticisms, the Commission cites that they used the best available evidence on diet and human health, and that their conclusions are based on consistent evidence from a wide collection of studies. These include randomised controlled feeding studies, randomised trials assessing weight, randomised trials assessing the risk of a specific disease, and long-term epidemiology studies involving hundreds of thousands of people over a number of decades. However, they note that in certain instances only a limited number of studies were available, such as for randomised trials looking at the risk of specific diseases. This is because of the inherent problem with nutritional research in that clinical trials on diet and human health are often not possible because they need people to adhere to an assigned diet for a long period of time, which has ethical implications.
Vitamin and mineral supplements are not explicitly part of the PHD, but the report indicates they can sometimes be necessary. To transition to a planetary health diet, rich countries would need to reduce (but not eliminate) meat consumption. The countries shown in pink consume less fruit than recommended by the PHD and other dietary guidelines.
Affordability and Accessibility
The EAT-Lancet report spurred discussions on how changes to government policies could be used to make healthy diets more affordable. Severe inequalities in the food system must also be ended to achieve healthy and sustainable diets, the researchers said. The wealthiest 30% of the world’s population generates more than 70% of food-related environmental damage, it found. Furthermore, 2.8 billion people cannot afford a healthy diet and 1 billion are undernourished, despite enough food being produced globally. The food system is also failing the 1 billion people living with obesity, the report said.
The report recommends shifting taxes to make unhealthy food more costly and healthy food cheaper, regulating the advertising of unhealthy food and using warning labels, and the shifting of today’s massive agricultural subsidies to healthier and more sustainable foods.
Adaptations and Variations
As of 2023, several studies have proposed variations of the PHD that are adapted to different cultures and regions. The PHD is flexible, allowing it to be adapted to local tastes, and can include some animal products or be vegetarian or vegan. However, all versions advise eating more vegetables, fruits, nuts, legumes and whole grains than most people in the world currently eat. In many places, today’s diets are unhealthy and unsustainable due to too much meat, milk and cheese, animal fats and sugar.
Researchers-including students of Christopher Golden, associate professor of nutrition and planetary health-and chefs and culinary historians have been translating the PHD to a variety of cuisines from around the world.
Examples include:
- Costa Rica: A healthy take on the traditional casado (meaning “married man”) combination of dishes, prepared by Hannia Campos, a nutrition researcher at the Universidad de Costa Rica.
- Greece: Meal designed by student Simone Wahnschafft, who took Golden’s course in 2020.
- Vietnam: Meal by Chef Mai Pham, Star Ginger and Lemon Grass Restaurant in Sacramento.
- West Africa: Meal by Oldways, a nonprofit food and nutrition organization, using its African Heritage Diet.
Implementation and Policy Changes
Moving diets towards the PHD could be achieved by helping consumers make better everyday choices, said Prof Line Gordon, director of the Stockholm Resilience Centre, for example by shifting taxes to make healthy foods cheaper, and putting warning labels on unhealthy foods. “But it is not just about getting prices lower, it’s also about bringing purchasing power up so that people can afford a healthier diet” she said.
“Our recommendations are grounded in scientific evidence and real-world experience,” Gordon said. “Changes are already under way, from school meal programmes to regenerative agriculture and food waste reduction initiatives.” England banned price promotions on unhealthy foods on Wednesday and will ban advertising such foods online.
Reception and Media Coverage
The PHD was largely well-received by the academic community. However, in social media discussion and in the media, responses to the report were highly polarised and the report became framed as a culture war issue. Media coverage was also divided. The UK newspaper The Guardian and the US news outlet CNN have given the diet positive coverage.
The launch of the PHD in 2019 led to attacks from meat industry interests.
Who Should Follow the PHD?
It’s worth bearing in mind that the reference diet set out in the PHD is aimed at an average moderately active adult and is not relevant to children under two years, older people, pregnant or breast-feeding women and in some cases pre-menopausal women. As with any dietary change, it's best to speak to your doctor before making any changes, especially if you have an underlying health condition or are on medication.