RAY SUAREZ: Travel across indonesia's most populous island -- Java -- and it's hard to imagine going hungry here.
The intensely cultivated fields are bursting with green -- rice, potatoes, bananas, tea.
But head to one of the many slums in Jakarta, and it gets easier to understand how vulnerable poor people can be.
WOMAN IN SLUM: Food prices have been going up sharply. Rice, eggs, oil...it's all going up.
Back in 2008 when food prices soared worldwide, people in the developing world who had been moving ahead economically were pushed back into poverty, and hunger.
Josette Sheeran heads the united nation's world food program.
JOSETTE SHEERAN, U.N. World Food Program: We saw the number increase by 140 million people, virtually overnight in 2008. So we went from about 900, 860 million hungry people in the world to a billion in about a year's time span. The world bank says that 44 million people were added to the ranks of the extremely poor and hungry in the past year because of the rise in food prices.
RAY SUAREZ: Sheeran says the food price indexes in 2011 are even higher than they were in 2008. In Indonesia, rising food costs means more expensive rice, a three-times-a-day staple food here. Its cost has risen 25 percent in just the past year.
When poor people have to pay more, the share that food takes from the family budget soars. Muhammad Chatib Basri is an Indonesian economist.
MUHAMMAD CHATIB BASRI, economist: If you look at the basket of consumption for average people, the proportion of food is about 40 percent. But if you're talking about the basket of poverty, in the poor people, the proportion of food is almost 70 percent.
RAY SUAREZ: Sapta Mega Pratiwi has brought her 15-month old son Ahmad to a regional hospital.
Is there enough food in your house?
SAPTA MEGA PRATIWI: Sometimes there's food, sometimes there's not. We don't earn enough money to always afford food.
RAY SUAREZ: When doctors first saw him, just a few week ago, he was a little over 15 pounds…far too light for a child that age. He has a belly, skinny legs, brittle hair, all classic signs of poor nutrition.
Dr. Saptarini Nurul Jamil runs the emergency nutrition center at the hospital. She sees more children like Ahmad when food prices are high.
DR. SAPTARINI NURUL JAMIL: Yes, the situation is parallel with the situation in the country. There are always basic problems of poverty, but it becomes a bigger problem when food prices go up and ultimately leads to malnutrition. When the economy goes down, more people lose their jobs or their salary is reduced and so they no longer can afford nutritious food.
RAY SUAREZ: Dr. Saptarini said Ahmad will get better. In just a few weeks of supplemental feeding, he's up to just over 17 pounds.
Other children aren’t so lucky. One out of every four Indonesian children doesn't get even 70 percent of the daily recommended allowances for nutrients. That means suffering today, and it robs the future.
JOSETTE SHEERAN: There's scientific consensus that when a child is born about 60 percent of their brain is formed. And the next three years in life, if they don't have adequate nutrition their brain will not form properly. I actually carry with me to show world leaders this chart. It shows two brains. This one of a child who was properly nourished, a three year old, this one of one that was malnourished. The actual volume of the brain is reduced about 40 percent.
RAY SUAREZ: Which leads to students who can't learn as much, and workers who can't work as hard.
DR. SAPTARINI NURUL JAMIL: If a malnourished child doesn’t get treatment early he can lack energy. He can have learning issues in school. And if a pregnant woman is malnourished, her baby will be born unhealthy and it will start a terrible cycle.
RAY SUAREZ: Even if you can afford to put some food on the table, many people -- especially those with large families -- face challenges.
One international aid group found that families were literally driven onto the street by tiny kitchens and even tinier food budgets. They found that they were giving their children food that was cheap and filling, but not necessarily nutritious.
On a cluster of streets in a poor neighborhood in West Jakarta, bright new colorful food carts are offering a healthier alternative.
USYE UMAYAH, Mercy Corps: In our cart, we provide food: healthy, nutritious but also affordable for the family -- especially for the low income.
RAY SUAREZ: Usye Umayah runs a Mercy Corps program that sends food carts out every morning with popular foods, but with added protein and vitamins.
USYE UMAYAH: We develop a menu, which is affordable by these families, but also we adding some more nutrition. It's really dense, nutritious for the children. And this is meeting 29 percent calories for a children under five.
RAY SUAREZ: Twenty-four year old Anisa Fihria says she knows she's feeding her 18-month-old son healthier food now.
Does being involved in that program also teach basic nutrition?
ANISA FIHRIA: Yes, he shares information about what nutrition is in the food. Like carrot contains Vitamin A and beans are good for Vitamin B12 and coconut is good for the bones.
RAY SUAREZ: The benefits don't end there. The carts provide steady employment and profit for the sellers, and work for kitchen staff preparing the food for sale.
It's a win all around, and changes the lives, and prospects of poor kids.
But it's a band aid, really, since the forces that drive rising food prices are far beyond the control of hard-working food sellers.
There are so many factors that influence food prices. One key one is energy, which is used not only to grow and transport the food, but increasingly food is being used as energy.
You can see the effect with palm oil. When crude oil got expensive, there was a run on the indonesian palm oil supply to use as biofuel instead of food.
MUHAMMAD CHATIB BASRI: I think we are entering a new era of high commodity prices and high energy prices. In the last 10 years we see evidence that higher energy prices means also higher commodity prices. Because people use commodity not only for cooking, for example, but also for substitute for energy.
RAY SUAREZ: Food production is also a problem. Although Indonesia is the world's third largest grower of rice, it still has to rely on imports of the grain. The government is trying to implement self-sufficiency polices. But so far there's a limit to how much food can be produced. It's a problem around the world.
JOSETTE SHEERAN: For the first time in most people's memory we're in a post-surplus world. There is no surplus of food in the world and you have one bad drought or one bad flood as we're seeing in the Midwest in America, it will impact the price of food globally.
RAY SUAREZ: Those rising prices are going to continue to make it more difficult for babies like Ahmad Maulana and other chronically malnourished children around the world.