When we tell people we analyze the environmental and nutritional impacts of food, we're almost always met with the same question: “So, what should I eat?” It's a deceptively complex question that highlights one of the greatest challenges facing our food systems today—how do we nourish a growing global population while protecting the planet we all share?

This challenge has driven us at the Global Alliance for Improved Nutrition (GAIN) to develop a new approach that we're excited to share in our latest briefing paper, "Nourishing People and Planet: Enviro-Nutritional Insights into Local Foods for Policy, Programmes, and Industry."

The Twin Crises We Face

Our world confronts two interconnected emergencies. Environmental degradation threatens our planet's future, with food systems responsible for approximately one-third of greenhouse gas emissions and 70% of freshwater consumption. Meanwhile, malnutrition affects every country globally, costing an estimated $3.5 trillion annually. Over 730 million people are undernourished, while 2.5 billion adults live with overweight or obesity.

Too often, these problems are treated separately. Policymakers receive different messages from nutritionists and environmental scientists. Environmental assessments typically measure food impacts per kilogram or calorie, ignoring nutritional value. This can result in misleading comparisons—is a kilogram of white rice really comparable to a kilogram of nutrient-rich spinach?

A Promising Approach: Nutritional Life Cycle Assessment

This is where nutritional Life Cycle Assessment (nLCA) comes in. By incorporating foods' nutritional value into environmental footprint assessments, nLCA provides a more holistic view of food sustainability. Instead of measuring impacts per kilogram or calorie, we measure them per unit of nutritional value, using our innovative Nutritional Value Score that rates foods from 1 to 100 based on both essential nutrients and factors predictive of non-communicable disease risk.

Our recent case study in Indonesia illustrates nLCA's power. Indonesia faces significant malnutrition in all its forms alongside environmental pressures from deforestation and land degradation—making it an ideal test case for this methodology.

Surprising Insights from Indonesia

When we analyzed 90 commonly consumed Indonesian foods, the results challenged many assumptions. Dark green leafy vegetables emerged as clear winners, offering high nutritional value with low environmental footprints. But the story gets more nuanced when you dig deeper.

Take spinach, for example. While it performs well on climate change metrics, its production often requires intensive irrigation and substantial fertilizer use, resulting in high water use and pollution footprints. Similarly, tuna scores well on land and water use but poorly on climate change due to fuel-intensive fishing practices.

Perhaps most surprisingly, some animal-source foods matched or even outperformed plant-based options. Chicken organs, whole milk, and certain fish had environmental footprints similar to top-performing plant foods like tofu and soymilk. Beef, while still one of the foods with the highest environmental impact, had lower environmental impact when considering its high nutritional value.

Four Game-Changing Applications

What excites us most about this new holistic nLCA approach is its versatility. We've identified four major use cases:

1. High-level strategic decisions: Policymakers can compare food groups to inform dietary guidelines and agricultural subsidies. Our Indonesian analysis suggests prioritizing vegetables could maximize nutritional benefits while minimizing environmental harm.

2. Within-category optimization: Programme managers can identify the best options within specific food groups. Among protein sources, for instance, tofu, tempeh, chicken organs, whole milk, and yogurt consistently outperform most alternatives. GAIN applied this same approach to improve the resilience of the tempeh value chain in Indonesia.

3. Multi-indicator profiling: By examining multiple environmental indicators, we reveal important trade-offs. A food performing well on climate metrics might score poorly on water use, highlighting the danger of focusing solely on carbon footprints.

4. Supply chain hotspot identification: nLCA pinpoints where environmental impacts occur along the value chain. In Indonesia, primary production accounts for the largest share of climate impacts for most foods, directing attention to where innovation is most needed.

The Path Forward

As we face the urgent need to transform our food systems, nLCA offers evidence-based guidance for navigating complex trade-offs. But tools are only as powerful as their application. Moving forward, we need to expand nLCA use globally, especially in low- and middle-income countries where malnutrition burdens and environmental pressures are highest. We must strengthen capacity among policymakers and practitioners to interpret and apply these insights. Most importantly, we need partnerships across government, academia, the private sector, and civil society to translate evidence into action.

The question “What should I eat?” may never have a one-size-fits-all answer. But with tools like nLCA, we can ground responses in both nutritional science and environmental reality. We invite policymakers, programme leaders, industry actors, and researchers to explore the full briefing paper and use its insights to help build food systems that truly nourish both people and planet.