NEW ORLEANS — The complexity of developing a sustainable food production model that preserves resources but also nourishes consumers was discussed during the Institute of Food Technologists annual meeting and food expo. Feeding an estimated 9 billion people by the year 2050 will require a sustainable food system that makes the most of limited resources while protecting the world’s fragile ecosystem, according to the session’s speakers.

“What we do in the next 10 years will set the stage for the next 50 years,” said Andrew Henderson, professor and area director, Center for Agriculture and Rural Sustainability at the University of Arkansas.

Among the challenges to a sustainable world food system include limited land availability, soil health, water scarcity, an uncertain supply and dependence on energy, climate change and greenhouse gas emissions.

“We are going to have to produce 50% to 100% more fuel, food and fiber from the same land over the next 50 years,” Dr. Henderson said. “We need to do this while preserving the world’s biodiversity. If not, our very system of being will be endangered.”

Jennifer Wilkins, a professor with the division of nutritional sciences at Cornell University, said “a whole diet approach” to sustainability looks at how much land is required to produce food based on different dietary scenarios. Communities, she said, consider their “foodprint” — the amount of land required to support one person on a specific diet in a specific geographic region for one year. Local food systems, said Ms. Wilkins, are more economically viable, requiring less transportation and energy.

She added that a sustainable food system considers which foods are essential, which foods are luxuries, and how food is transported, processed and packaged. A sustainable food system limits waste and optimizes land usage. Vegetarian diets, and those with limited meat and dairy, may feed the most people.

“The key is balancing nutrition and environmental costs,” said Adam Drewnowski, a researcher at the University of Washington Center for Obesity Research. “Energy dense foods — those with high-sugar and high-calories — are often more cost effective, but not efficient.

“Low-cost diets tend to be energy dense but nutrient poor. Sustainable diets must be high in nutrition, socially acceptable and not deplete the planet's resources.”