Nutrition and mental development.

It has been difficult to assess the effects of malnutrition upon mental development because of the environmental alterations that invariably accompany malnutrition, even in animal models. In rats, maternal behavior is altered whenever offspring are malnourished, in part in response to the altered stimulus characteristics of the offspring. It is difficult to assess whether these alterations in environment are detrimental because they are adaptive in promoting the growth of the pups. Environmental stimulation may to some extent reverse the brain effects of malnutrition and can remediate some of the behavioral effects.