These findings support the hypothesis for children and mothers. Based on ZLL, there is evidence that childhood and nutrition have improved somewhat for each younger generation. Persistent environmental adversity during growth resulted in growth deficits for LL and SH for the mothers and grandmothers.

Our findings partially support the hypothesis that living conditions experienced by recent maternal ancestors (F1 and F2 ) during their growth period influence the growth of descendants (F3 ). Results suggest that LL is more sensitive to intergenerational influences than is total height and that the transition from a traditional rural lifestyle to urban conditions results in new exposures for risk in human physical growth.

Objectives: To analyze the association between birth mode and fat mass index (FMI= fat mass [kg]/height [m] 2 ), and z-score values of waist circumference (WCZ) and sum of triceps and subscapular skinfolds (SumSkfZ) in a sample of 256 6 to 8year-old urban Maya children from the cities of Merida and Motul in Yucatan, Mexico. waist circumference and skinfolds in children and height and weight in their mothers. Body composition was estimated in both generations through bioelectrical impedance analysis. Data on children's birth mode and birth weight were obtained from birth certificates. A pre-validated questionnaire for mothers was used regarding household living conditions. Multiple regression models were used to analyze the association between birth mode and adiposity parameters adjusting for the effect of place of residence, household crowding index, children's birth weight and maternal fat mass (FM). Separate regression models were run for boys and girls. Results: Caesarean-born children comprised 43% of the entire sample.Caesarean section (CS) was found to be associated with higher values of body adiposity in girls, but not in boys. Specifically, our models predicted that girls born by CS had an increased value of 0.817 kg/m 2 in FMI and showed higher standard deviations values for WCZ and SumskfZ (0.29 and 0.32 SD, respectively) than girls who were delivered vaginally. Discussion:Our results support the hypothesis that CS is associated with increased levels of adiposity in childhood, but only in girls.

Our results suggest that better living conditions experienced by the mothers and daughters during their childhood may lower mean AAM in daughters in the context of populations that show important intergenerational changes in their social and economic conditions.

Adolescents with excess weight (overweight + obesity) reported being less physically active. SES and PA were strongly related to growth and body fatness in the studied adolescents.