Are girls fed better than boys in the third world?

I came across this:

"Globally, girls under five years are more likely to be overweight than boys, which – together with obesity – may lead to cardiovascular disease, diabetes, muculoskeletal disorders and some cancers later in life."

here:

http://www.who.int/mediacentre/factsheets/fs334/en/index.html

It made me wonder why more girls would be overweight. Since this is a GLOBAL number it would seem likely young girls in the third world are fed better than boys and so can become overweight, which in many poor countries is generally sign of being treated as privelliged and might be a lot better than vein underweight.