In the 21st century, the world faces three interconnected challenges: climate change, obesity, and undernutrition, notes Sadhvika Srinivas of The New Indian Express.

Together, these issues have been described by the Lancet Commission as the Global Syndemic, a confluence of pandemics driven by socioeconomic forces that threaten both human health and the environment.

At the heart of this crisis lies our dietary patterns, which directly influence non-communicable diseases (NCDs), nutritional deficiencies, and the environmental impact of food systems.

One solution gaining worldwide attention is the adoption of plant-based diets. Unlike a single, rigid diet, plant-based eating spans a wide spectrum, from strict vegan diets that eliminate all animal products to more flexible approaches such as the Mediterranean diet, the New Nordic diet, or the Planetary diet proposed by the EAT-Lancet Commission. What unites them is a focus on vegetables, fruits, whole grains, legumes, nuts, and healthy fats, with limited or no consumption of red meat and highly processed foods.

Health benefits of plant-based eating

Scientific evidence consistently shows that plant-based dietary patterns support weight management, lower the risk of cardiovascular disease (CVD), and aid in the prevention and management of type 2 diabetes. A high intake of red and processed meats has been linked with obesity, cancer, and diabetes due to their saturated fat and salt content. In contrast, diets rich in plant foods, complemented by moderate intake of fish and seafood, provide essential omega-3 fatty acids that reduce the risk of cardiac death.

Research also reveals that vegetarians and vegans tend to have a lower risk of CVD compared to omnivores, with vegetarians showing up to a 15% reduction in relative risk. Similarly, plant-based diets improve blood sugar regulation, lowering the risk of type 2 diabetes, independent of body weight. These findings strengthen the case for recommending plant-forward diets as a preventive strategy against the growing epidemic of lifestyle diseases.

The benefits of plant-based eating extend beyond personal health. Studies show that reducing meat and animal product consumption leads to significantly lower environmental impacts, including reduced greenhouse gas emissions, water use, and deforestation. This link between diet and sustainability is vital, as our current global food systems contribute heavily to climate change.

The Planetary Health Diet proposed in 2019 highlights how a balanced, predominantly plant-based diet can simultaneously meet nutritional needs and align with environmental goals. It emphasises vegetables, fruits, legumes, nuts, whole grains, and unsaturated fats, while allowing only small quantities of poultry and fish, and minimal red meat and processed foods. Widespread adoption of such diets could play a transformative role in addressing the Global Syndemic.

Despite their advantages, plant-based diets are not without challenges. If poorly planned, they may lead to deficiencies in vitamin B12, vitamin D, calcium, iron, iodine, selenium, zinc, and niacin (B3). To avoid this, individuals following vegetarian or vegan diets must include a variety of nutrient-rich plant foods and, where necessary, fortified foods or supplements.

Low- and middle-income countries face additional hurdles in adopting healthy plant-based diets. The ongoing nutrition transition, a shift from traditional diets to “Western” patterns high in sugar, sodium, saturated fats, and processed meats- has worsened rates of obesity and NCDs. At the same time, barriers such as food insecurity and lack of nutrition education make it difficult for populations to embrace healthier plant-forward patterns.

This highlights the need for targeted health policies, including supplementation and fortification programs, to ensure nutritional adequacy while promoting plant-based eating across diverse populations.

The evidence is clear: well-planned plant-based diets offer a powerful tool to improve human health and reduce environmental damage. They can lower the global burden of non-communicable diseases, support a healthy weight, and reduce risks of cardiovascular disease and diabetes. At the same time, they help curb the food system’s contribution to climate change.

For policymakers, nutritionists, and individuals alike, the message is simple: shifting towards plant-based dietary patterns is not just a lifestyle choice; it is a necessity for the future of both people and the planet.