ABNORMALLY HIGH NOURISHMENT DURING SENSITIVE PERIODS RESULTS IN BODY-WEIGHT CHANGES ACROSS GENERATIONS

Objective: This study asked whether a brief period of overnutrition du ring a developmentally sensitive time could impact the individual's ad ult weight and that of succeeding generations. Research Methods and Pr ocedures: Female rat pups (F-1 generation) were randomly assigned to 1 of 3 groups: (1) a control group that was naturally reared by mothers ; (2) another control group implanted with chronic gastric fistulas on postnatal day 4 and fed enough formula to match the growth of the mot her-reared group; and (3) an experimental group gastrostomized and inf used from day 8 through day 16 with a greater quantity of food than ga strostomy-reared controls (OF), On postnatal day 16, both gastrostomy- reared groups were returned to normal litters. Adult F-1 females from overfed and mother-reared groups were bred with normal males to yield an F-2 generation. F-2 adult females were bred to normal males to prod uce an F-3 generation. Results: When adult, the F-1 experimental group was heavier than control groups. F-2 adults from OF mothers were smal ler than those from the control group. F-3 animals from OF grandmother s were heavier at weaning than F-3 descendants from mother-reared anim als. Discussion: Excess nourishment during a developmentally sensitive period changed the metabolic phenotype of one generation so dramatica lly that the gestational development and subsequent phenotype of two s ucceeding generations were also changed. The experiment models fetal e ffects of gestational diabetes in humans and may help to elucidate how , independent of genetic anomalies, secular changes can be detected ac ross generations.