Malnutrition in third world countries....a vicious cycle??

Not trying to sound mean, but I was watching a 60 Minutes thing on Plumpy'nut and there was a lot of little malnourished children. They were just laying there slack jawed and vacant eyed.....if these children survived to adulthood what kind of mental acuity could they really be capable of?? Without nutrition for proper brain development, would their IQ's be really low? And is this part of what keeps them poor?? Without the intelligence to make a better life for themselves, they just do what has always been done and nothing changes?