If those people are alive (as they observably are), then logically they are getting food.

When you're poor, you generally can only afford low quality food. Low quality food is bad for your health, resulting in many problems including obesity and diabetes.

Low quality food is generally processed grain. It's cheap to make and cheap to keep "fresh," which is why we have so much of it in the US. Think high fructose corn syrup, and almost anything that comes in a box, and do the thought experiment across the food chain from the farm, through manufacturing and distribution, to consumption and the doctor's office.

When you see a population of obese people, don't think that their food problem is solved; realize that the food they have practical access to is a problem. (And yes, many rich people in rich countries are obese and have a choice, but many of those obese people are poor and do not, and we're not talking about a rich country at the moment.)