The Contrasting Effects of Ad Libitum and Restricted Feeding of a Diet Very High in Saturated Fats on Sex Ratio and Metabolic Hormones in Mice1

Abstract

Skewing of the sex ratio towards males occurs among pups born to mice fed a very high saturated fat (VHF) diet. In the present study, we tested whether the fat content of the VHF diet rather than the number of calories consumed is responsible for this effect. Eight-week-old NIH Swiss mice were placed on the VHF diet either ad libitum (VHF) or in a restricted manner (VHF-R). The VHF-R mice gained weight at a similar rate to controls fed a standard chow diet. Mice were bred at 15 wk and subsequently at 26 wk and 35 wk of age. Overall, the VHF, VHF-R, and control groups delivered 244, 242, and 274 pups, respectively, with male proportions of 0.60, 0.43, and 0.48, respectively. The pup sex ratios of the VHF group (favoring males) and VHF-R group (favoring females) each differed from 0.5 (P < 0.01). The sex ratios also differed (P < 0.0001) between the VHF and control groups, and between the VHF and VHF-R groups. Within the diet groups, maternal body weight had no effect on sex ratio. Serum leptin concentrations among the dams were similar in the VHF and VHF-R groups but higher than in the control group, while the IGF1 and corticosterone levels were comparable in all three groups. Therefore, the atypical sex ratios of offspring born to dams on the VHF diet seem to be influenced by the amount of fat consumed. Since males fed the VHF diet had neither more Y-sperm nor sired more sons than daughters, the dietary effects are manifested exclusively through the female.

Reproductive performance and gestational effort in relation to dietary fatty acids in guinea pigs

“…A higher energy intake and the resulting improved body condition of a mother may also favor the birth of male offspring [45], but we found no differences in the sex ratio at birth or in the ratio of dead and alive born male and female pups. These results are in contrast to a variety of mechanisms describing how diet and available energy may skew the sex ratio [46], which has also been reported for high-fat diets [9]. The present results suggest that guinea pigs generally produce more male offspring, which is apparently not affected by dietary fat intakes.…”

“…PUFAs in general, including ALA and LA, can also promote the prenatal development of rabbits and mice, resulting in increased body mass and improved physical condition at birth [6, 7]. Although less well studied, dietary intakes of non-essential saturated fatty acids (SFAs) can also improve reproductive performances by increasing the birth mass in rats [8] or the sex ratio at birth towards more male offspring in mice [9]. However, dietary SFAs may not only promote reproductive functions as PUFAs obviously do, since various effects on metabolic processes may be detrimental for an individual [10, 11].…”

Maternal exposure to bisphenol A and genistein has minimal effect onAvy/aoffspring coat color but favors birth of agouti over nonagouti mice

“…Additionally, we examined the ratio of a/a to A vy /a pups to determine whether developmental exposure to BPA or any of the other compounds acted as a selective barrier to one genotype over the other, i.e., a/anonagouti versus A vy /a-agouti. Finally, we determined whether exposure to BPA, G, and EE had effects relative to parity (and hence age of the dams), because earlier studies have indicated that dietinduced biases in offspring sex ratio become more extreme in late parities than at first parity when the mice are young adults (28,29).…”

Reproductive Endocrinology 2011

“…A paper by Alexenko et al [7] in 2007 presented in the ESPE Yearbook 2008 showed that a in murine model a high caloric diet favored male offspring. In agreement with this, Mathews et al [8] in 2008 showed similar results in a study on humans, where mothers with a high caloric intake prior to conception had a higher proportion of boys.…”

“…Conclusion: The combination of maternal diet with timing of intercourse is capable of increasing the probability of conceiving a girl (p = 0.005). The observed percentage of female babies for all 32 women satisfying the prediction rule was 81% (95% CI 68-95%).A paper by Alexenko et al [7] in 2007 presented in the ESPE Yearbook 2008 showed that a in murine model a high caloric diet favored male offspring. In agreement with this, Mathews et al [8] in 2008 showed similar results in a study on humans, where mothers with a high caloric intake prior to conception had a higher proportion of boys.…”