Effects of high-fat diets on fetal growth in rodents: a systematic review

Abstract

Background Maternal nutrition during pregnancy has life-long consequences for offspring. However, the effects of maternal overnutrition and/ or obesity on fetal growth remain poorly understood, e.g., it is not clear why birthweight is increased in some obese pregnancies but not in others. Maternal obesity is frequently studied using rodents on high-fat diets, but effects on fetal growth are inconsistent. The purpose of this review is to identify factors that contribute to reduced or increased fetal growth in rodent models of maternal overnutrition. Methods We searched Web of Science and screened 2173 abstracts and 328 full texts for studies that fed mice or rats diets providing ~ 45% or ~ 60% calories from fat for 3 weeks or more prior to pregnancy. We identified 36 papers matching the search criteria that reported birthweight or fetal weight. Results Studies that fed 45% fat diets to mice or 60% fat diets to rats generally did not show effects on fetal growth. Feeding a 45% fat diet to rats generally reduced birth and fetal weight. Feeding mice a 60% fat diet for 4–9 weeks prior to pregnancy tended to increase in fetal growth, whereas feeding this diet for a longer period tended to reduce fetal growth. Conclusions The high-fat diets used most often with rodents do not closely match Western diets and frequently reduce fetal growth, which is not a typical feature of obese human pregnancies. Adoption of standard protocols that more accurately mimic effects on fetal growth observed in obese human pregnancies will improve translational impact in this field. Electronic supplementary material The online version of this article (10.1186/s12958-019-0482-y) contains supplementary material, which is available to authorized users.

The Impact of Maternal High-Fat Diet on Bone Microarchitecture in Offspring

“…One outstanding question is whether the detrimental effects on offspring skeleton are driven by maternal obesity, maternal HFD, or both. In humans, most studies explore the effects of obesity during pregnancy, commonly assessed by measuring body mass index rather than dietary patterns (46). In rodents, the majority of studies implemented a maternal HFD regime at least 4 weeks before mating.…”

“…Unlike in humans, changing the diet of a rodent from HFD to CD induces rapid weight loss (47). This could be overcome using embryo transfer following pre-conception maternal HFD, placing embryos into CD-fed recipients (46).…”

Circadian Clock, Time-Restricted Feeding and Reproduction

“…There is strong evidence that high caloric intake has negative impacts on principal body functions, such as endocrine effects, altered liver metabolism, and cholesterol imbalance [137][138][139]. Developmental programming, an action associated with nutrition during pregnancy and early life, imposes continual effects on the health of offspring, as shown through the reproductive repercussions of high-fat diets (HFD) [140,141]. It has been demonstrated that high fat and sugar intake induces alterations in circadian clock function, which seems to be a factor in female reproductive timing, since such changes may harm synchronization between circadian rhythmicity and central or peripheral components.…”

“…It has been demonstrated that high fat and sugar intake induces alterations in circadian clock function, which seems to be a factor in female reproductive timing, since such changes may harm synchronization between circadian rhythmicity and central or peripheral components. Recently, several studies have shown that high caloric intake leads to premature aging, altered sleep, and disruption in circadian rhythmicity [141][142][143][144]. Highlighting their significance, high-fat diet intake affects the ovarian circadian clock [145].…”

Metabolic and behavioural effects in offspring exposed to maternal sucrose consumption: a systematic review and meta-analysis of data from rodent models

“…17 However, such studies are inevitably subject to a range of confounding factors that limit their ability to identify causality. Because they can eliminate confounds, animal models have advanced our understanding of the biological mechanisms involved in maternal overnutrition, 20,21 including high-sugar diets. 22 Given SSB intake is a prime target for the prevention of excessive weight gain during pregnancy, it is important to validate the epidemiological findings [17][18][19] in animal models.…”