The number of people suffering from hunger last year rose at the fastest pace since at least the beginning of this century as conflicts and climate-related issues curbed access to food.

The number of people who were categorized as hungry increased by about 38 million to 815 million in 2016, accounting for 11 percent of the global population, a report from the United Nations found.

The findings also show that food security has worsened in some peaceful places amid economic slowdowns, and 13 percent of adults around the world are battling obesity.

"These recent estimates are a warning signal that achieving the goal of a world without hunger and malnutrition by 2030 will be challenging," the U.N.'s Food and Agriculture Organization (FAO) said in the report, published Friday.

"Deteriorations have been observed most notably in situations of conflict, often compounded by droughts or floods, linked in part to the El Niño phenomenon."

More than half of those who are hungry live in areas affected by violent conflicts that have crippled local agriculture and restricted access to food supplies. Famine was declared earlier this year in South Sudan, while Nigeria, Somalia and Yemen have suffered more food shortages.

The increase in undernourished also came as a gauge of food prices rebounded from a seven-year low, even amid a global glut of grains.

Asia has the largest number of hungry people — 520 million — and sub-Saharan Africa has the highest proportion, with 20 percent of the population affected.

Other key findings:

• 12 percent of people in Asia were hungry.

• 155 million children under 5 were too short for their age.

• 52 million children aren't heavy enough for their height.

• One-third of people in eastern Africa were undernourished.

• Adult obesity is also rising everywhere at a faster pace.

A number of countries heavily dependent on shipping out commodities have seen export and fiscal revenue plunge in recent years amid lower oil and mineral prices, according to the report.

That has hurt food availability and the ability to protect poor households against higher domestic food prices.

While the amount of undernourished people around the world rose to the highest since 2008 last year, it was still about 14 percent below a peak set in 2003. Under the 2030 Agenda for Sustainable Development, world leaders have pledged to try to eradicate hunger and malnutrition by 2030.

The situation is likely to improve this year, U.N. FAO Secretary General Jose Graziano da Silva said at a news conference in Rome, citing an improving economy, fading odds of El Niño and progress made in war-torn areas.

"To save lives, we must save livelihoods," he said. "This is the way forward that we see to eradicate hunger and extreme poverty once and for all."

The report was also jointly prepared by the U.N.'s International Fund for Agricultural Development, the World Food Programme, the World Health Organization and the United Nations Children's Fund.