Food, health, planet: the planetary and longevity diet for a healthier and more sustainable future

Food as a Bridge Between Health and the Environment

In recent years, nutrition has become an issue that extends beyond individual health. Daily food choices are also linked to the use of natural resources, greenhouse gas emissions, water consumption, land use, and biodiversity.

The relationship between diet and the environment is particularly important because the food system simultaneously involves agricultural production, livestock farming, processing, distribution, consumption, and waste management.

From this perspective, changing the composition of the diet can be one of the strategies for simultaneously addressing the determinants of health and the environmental footprint of food.

Nutritional research in recent years has therefore increasingly considered a dual objective: a diet capable of supporting long-term health while being compatible with the planet's ecological limits.

The Planetary Diet

One of the best-known models is that developed by the EAT-Lancet Commission. Published in 2019, the model proposes a transformation of global eating habits based primarily on increasing plant-based foods and reducing, in particular, red and processed meats.

The planetary diet prioritizes:

• vegetables and greens;
• fruit;
• legumes;
• whole grains;
• nuts and seeds;
• unsaturated vegetable oils, particularly extra virgin olive oil, in the Mediterranean context.

The consumption of foods of animal origin is not necessarily excluded, but is kept to smaller quantities, with room for fish, eggs, dairy, and poultry.

The goal is therefore not to propose a single identical diet for every population, but to define a nutritional direction compatible with human health and the sustainability of the food system.

The EAT-Lancet model has also highlighted the need to consider the cultural, economic, and geographical differences between the various populations. A sustainable diet must therefore also be accessible, culturally acceptable, and nutritionally adequate.

More Plant-Based, Fewer Ultra-Processed Foods

The value of a predominantly plant-based diet does not depend solely on the absence or reduction of meat.

It is also important which plant-based foods are chosen.

A diet consisting mainly of legumes, vegetables, fruit, whole grains, nuts, and seeds has very different nutritional characteristics from a diet rich in industrial products formulated from refined flours, sugars, fats, and numerous additives.

Minimally processed plant-based foods provide fiber, vitamins, minerals, polyphenols, carotenoids, and other bioactive compounds. Furthermore, fiber is metabolized by the gut microbiota, producing metabolites including short-chain fatty acids, which are involved in regulating intestinal and immunometabolic homeostasis.

These mechanisms help explain why the overall quality of the diet is more important than simply classifying foods as "plant-based" or "animal-based".

The Longevity Diet

Another approach that shares several elements with the planetary model is that defined as the longevity diet.

The model draws inspiration from traditional Mediterranean nutrition, epidemiological studies of populations characterized by a greater life expectancy, and experimental research on the biological mechanisms of aging.

Among its recurring elements are a high intake of plant-based foods, legumes, and whole grains, a moderate protein intake, and a predominance of plant-based protein sources.

Extra virgin olive oil is an important source of fat, while added sugars, refined flours, and frequently consumed foods of animal origin are limited.

In some versions of the model, the consumption of fish is also included, preferably small fish from sustainable sources, while dairy and cheese are consumed occasionally.

Another characteristic element is the interest in moderate calorie restriction and controlled periods of fasting or reduced-energy intake, when appropriate and under proper supervision.

It is important to emphasize that these approaches should not be interpreted as therapies for specific diseases. Their relevance mainly concerns the relationship between diet, metabolism, aging, and the prevention of risk factors.

Possible Biological Mechanisms

A diet characterized by a high intake of plant-based foods can influence numerous biological processes associated with chronic diseases.

The high fiber content contributes to the regulation of glucose and lipid metabolism and the maintenance of intestinal function. Polyphenols found in fruit, vegetables, cocoa, tea, extra virgin olive oil, and other plant-based foods can interact with cell signaling pathways involved in the response to oxidative stress and inflammation.

The composition of dietary fats is also important. Replacing some saturated fats with unsaturated fats is associated with an improved lipid profile and, within the overall context of the diet, can contribute to reducing cardiovascular risk.

The Mediterranean model thus constitutes an important reference. Epidemiological and clinical studies have associated greater adherence to the Mediterranean diet with a lower incidence of cardiovascular events and, in several studies, with a reduction in certain metabolic and chronic outcomes.

One possible common element between diet, metabolism, and aging is represented by the cellular pathways that regulate energy availability and the response to nutrients, including AMPK, mTOR, sirtuins, and IGF-1. These systems participate in the regulation of cell growth, autophagy, the stress response, and metabolism.

The mechanistic evidence is interesting, but it does not mean that modulating a single molecular pathway through a particular diet can automatically translate into increased longevity in humans.

Planetary Health and Cardiovascular Health

The convergence between sustainability and the prevention of chronic diseases becomes particularly evident when observing the replacement of certain foods.

Reducing the consumption of red and processed meats and increasing the consumption of legumes, whole grains, vegetables, fruit, and nuts can simultaneously change the nutritional quality of the diet and its environmental footprint.

The benefit does not necessarily derive from an absolute prohibition of certain foods, but from the overall composition of the dietary model.

This aspect is also important from a public health perspective: small changes spread across millions of people can produce much more significant effects than changes adopted by only a minority.

The Environmental Impact of Food

Agriculture and the food system are responsible for a significant portion of the global environmental impact.

The main pressures include greenhouse gas emissions, land use, freshwater consumption, biodiversity loss, and ecosystem transformation.

Livestock farming, especially that associated with ruminants, generally has a higher climate footprint than the production of many plant-based foods, partly due to methane emissions and the use of land for feed.

For this reason, a transition toward dietary models characterized by a greater presence of plant-based foods can help reduce the environmental impact.

However, simplifications should also be avoided in this case. The environmental impact of a food depends on its production, origin, seasonality, processing, transport, storage, and waste.

Food sustainability is therefore a more complex issue than simply distinguishing between "plant-based" and "animal-based".

The Role of the Mediterranean Diet

In the Italian context, many principles of the planetary diet can be naturally integrated with the Mediterranean tradition.

Vegetables, legumes, whole grains, fresh and dried fruit, extra virgin olive oil, and aromatic herbs form a dietary foundation compatible with both numerous principles of preventive nutrition and a reduction in environmental impact.

The traditional Mediterranean diet does not perfectly coincide with the planetary diet or the longevity diet, but it shares significant commonalities: a predominance of plant-based foods, the quality of fats, dietary variety, and moderate consumption of animal-based foods.

This convergence is particularly interesting because it demonstrates that sustainability and dietary tradition are not necessarily opposing concepts.

From Theory to the Table

The transition toward a more sustainable diet does not necessarily require radical changes.

It can begin with a few daily choices:

more legumes, also used as a frequent alternative to animal proteins;

more vegetables, with a variety of colors and seasonal choices;

more whole grains, alternating wheat, oats, barley, spelt, and other grains;

fruit and nuts as regular components of the diet;

extra virgin olive oil as the main source of added fat;

fewer red and processed meats, especially when consumed frequently;

fewer ultra-processed foods, especially those rich in sugar, salt, and low-quality fats;

reduced food waste, which is an important component of sustainability.

Choosing seasonal products and, when possible, those from sustainable supply chains can also help reduce the overall impact.

A New Approach to Prevention

Perhaps the most compelling value of these dietary models lies in their ability to connect two concepts that have long been considered separately: disease prevention and environmental protection.

Cardiovascular diseases, type 2 diabetes, obesity, and numerous other chronic conditions are influenced by dietary, metabolic, and behavioral factors. At the same time, food production contributes to environmental pressures that affect the health of present and future generations.

Diet therefore becomes a true interface between the individual and the ecosystem.

This does not mean that there is a universal diet capable of ensuring health and longevity for everyone. Age, physiological conditions, physical activity, nutritional needs, dietary culture, and clinical conditions must always be considered.

However, it does mean that there is a general direction supported by a growing body of evidence: a greater presence of minimally processed plant-based foods, better-quality fats, more moderate consumption of animal-based foods, and a reduction in ultra-processed foods can form part of a dietary model that is favorable to both health and sustainability.

The Future Also Lies on the Plate

Transforming the food system certainly requires interventions at the agricultural, industrial, economic, and institutional levels. But part of the change can also begin with daily choices.

Breakfast, lunch, and dinner are, after all, decisions made thousands of times throughout life.

Choosing legumes, vegetables, whole grains, fruit, nuts, and good-quality fats more often means building a dietary model consistent with many of the goals of nutritional prevention. If these choices are accompanied by reduced waste and greater attention to sustainable production, they can also take on an environmental dimension.

The planetary diet and dietary patterns aimed at longevity are therefore not necessarily identical, but they converge on several fundamental principles: more plant-based foods, greater nutritional quality, moderation in the consumption of animal-derived foods, and a focus on sustainability.

In this perspective, food is not merely a source of energy and nutrients. It is also one of the everyday tools through which we can connect individual health, collective health, and the health of the planet.

Bibliographic references

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