What mothers eat in pregnancy may shape a child’s weight years later

Researchers tracked maternal diets throughout pregnancy and followed children to age four, revealing intriguing differences between whole fruits and vegetables, homemade juice, and commercially packaged drinks.

Study: Maternal Consumption of Fruits, Vegetables and Fruit Juices in Relation to Offspring Weight at 4 Years. Image Credit: RecCameraStock / Shutterstock

Maternal diet plays an important role in offspring development, beginning in utero. A recent study published in the journal Nutrients found that increased maternal consumption of fruits and vegetables during pregnancy was associated with lower odds of overweight or obesity in offspring at 4 years of age. However, overweight and obesity were more common among those with higher maternal intake of commercial (but not natural) fruit juices, though this was considered an exploratory finding.

Background

Childhood obesity has been increasing worldwide over the past decades, and Spain has the second-highest prevalence of this condition among European nations. Its associations with adverse physical and psychosocial outcomes have been documented.

For this reason, effective preventive strategies beginning in prenatal life are being actively explored. Maternal diet in pregnancy is especially important in helping to determine the intrauterine environment and may shape fetal metabolic programming as well, potentially affecting long-term obesity risk in the offspring.

Increased adherence to healthy dietary patterns during pregnancy is associated with improved growth, reduced adiposity, and lower childhood overweight/obesity risk. Such dietary patterns are typically high in fruit and vegetable consumption. These foods provide an abundance of essential vitamins, minerals, dietary fiber, and bioactive compounds with antioxidant and anti-inflammatory properties.

Maternal dietary habits may persist after childbirth, affecting the child’s developing dietary preferences and consumption patterns through mechanisms such as parental modeling and exposure to multiple flavors.

Previous studies exploring maternal fruit and vegetable (FV) consumption during pregnancy have focused primarily on birth weight and infant growth up to 6 months of age. Fruit juice consumption during pregnancy has also been inconsistently linked to offspring adiposity or overweight, and these studies have failed to differentiate between natural and commercial fruit juices.

To the authors’ knowledge, no prospective study had comprehensively examined maternal consumption of FV alongside different types of fruit juice in relation to childhood overweight and obesity. The current study aimed to examine these associations in children up to four years of age.

Study characteristics

The researchers drew data from the ECLIPSES trial, a community-based study carried out in Spain. All participants were healthy pregnant women, aged at least 18 years, with a gestational age of 12 weeks or less at recruitment.

The current observational study included 252 women from the trial who had provided data on their dietary habits via a food frequency questionnaire at 12, 24, and 36 weeks of pregnancy, and on the overweight/obesity status of their four-year-old children born from the index pregnancy.

Participants in this study had higher educational attainment and maternal age than others. In this sample, 24.6% of children were overweight or obese.

The average maternal intakes of fruit and vegetables were approximately 119 and 74.5 g/day, respectively. Fruit juice consumption averaged 105 g/day, with natural fruit juice accounting for 55% of the total.

Fruits and vegetables

Increased maternal FV intake was inversely associated with overweight or obesity in the offspring when comparing the highest tertile to the lowest. However, fruit and vegetable intake did not show separate associations with offspring weight outcomes.

Fruit juice consumption

Neither total nor natural fruit juice consumption was associated with overweight or obesity in the offspring. Conversely, commercial fruit juice intake was linked with higher odds of these outcomes, although the finding was considered exploratory because multiple correlated dietary exposures and comparisons were evaluated.

Importantly, “commercial fruit juice” was a broad category encompassing all commercially produced or packaged juices regardless of added sugar, including 100% packaged juice, juice from concentrate, nectars, and fruit drinks; these subtypes were not analyzed separately.

Sensitivity analyses produced broadly similar estimates to the primary results, although none of the associations reached statistical significance when intake was modeled continuously in 100 g/day increments. No evidence of departure from linearity was observed.

These findings add to the increasing evidence that maternal diet in pregnancy may influence offspring health. The authors postulate that the rich antioxidant and anti-inflammatory content of FV, stemming from multiple bioactive compounds, may reduce oxidative stress and systemic inflammation and regulate metabolic pathways.

Abundant dietary fiber in FV, coupled with the typically low glycemic load, may help with glucose regulation in pregnancy as well. The authors note that these are biologically plausible but cannot be proved through the findings of the current study.

Postnatal family eating patterns may also help explain the observed relationship, including exposure to FV in early childhood, the home food environment, and parental example. Previous studies have shown increased FV intake in early childhood when maternal diet in pregnancy is of higher quality.

This hypothesis could not be tested here, as the children’s dietary intake was not followed up on, nor was information on the home food environment available.

The authors suggest several possible explanations for the association of childhood obesity or overweight with maternal commercial fruit juice consumption in pregnancy. A previous compositional analysis cited by the authors reported higher sucrose and total carbohydrate contents in commercially available juices than in natural juices, while prenatal exposure to sweet flavors may potentially influence the development of taste preferences for sweet foods in the postnatal period.

Besides, commercial fruit juice consumption in pregnancy might be a marker of a broader lifestyle pattern within the family that affects the child’s obesity risk. As before, the study did not test any of these hypotheses.

Limitations

The observational nature of the study precludes causal inferences. In addition, residual confounding from maternal, family, and postnatal infant or child factors remains possible.

The results were not adjusted for gestational diabetes, paternal BMI, family socioeconomic status, or the child’s dietary and physical activity profile. Moreover, longitudinal data on the children’s dietary intake up to age 4 were unavailable.

A high rate of loss to follow-up from initial recruitment led to notable differences in maternal age and educational level between the initial and final samples, potentially introducing selection bias. Self-reported dietary intake might have been an additional source of error.

The relatively small number of overweight/obesity cases also increased the risk of statistical overfitting, while the multiple correlated dietary comparisons mean that chance findings cannot be ruled out, particularly for commercial fruit juice.

Finally, the study may not be generalizable to other populations.

Conclusion

The study found that higher maternal FV consumption was associated with lower odds of childhood obesity and overweight at age 4. An exploratory analysis also suggests that higher maternal consumption of commercial fruit juice was associated with higher odds of these outcomes.

Given its observational design, the study cannot establish causality and should not be considered to support specific dietary interventions. Future studies should follow up children in larger cohorts while adjusting for other maternal, family, and child-related factors that could affect this association. The underlying pathways also need to be elucidated.