Malnutrition is the worst global crisis in child health, and climate change will exacerbate the situation, according to Microsoft co-founder Bill Gates, who is now focused on philanthropy.

“If you don’t get the right food generally, both in utero and in your early years, you will never be able to catch up,” Gates told Reuters in an online interview last week, referring to the physical and mental development of children, which is compromised without proper nutrition. Children without adequate nutrition are also more vulnerable to diseases such as measles and malaria and to early death.

“About 90% of the negative impact of climate change operates through the food system. It’s when your crops basically fail for years due to drought or excessive rainfall,” he said.

Gates gave the interview ahead of the annual Goalkeepers Report from the Bill and Melinda Gates Foundation, which tracks progress on the UN Sustainable Development Goals (SDGs) related to poverty reduction and health improvement. The report includes these projections.

In 2023, the World Health Organization estimated that 148 million children experienced stunted growth and 45 million suffered from wasting.

Gates called for increased funding for nutrition, particularly through a new UNICEF platform aimed at coordinating donor funding, the Child Nutrition Fund, as well as for more research. However, he stressed that the funds allocated for this purpose should not be taken away from other proven initiatives, such as routine childhood vaccinations.

“Nutrition has not been adequately researched… it’s striking how important it is,” he added, noting that initiatives like dietary fortification or improving prenatal access to multivitamins could be as effective as some vaccines in improving child health in the world’s poorest countries.

The Gates Foundation announced in January that it plans to spend more than ever on global health this year—$6.8 billion—as broader funding efforts face delays.