Prenatal and early childhood nutritional exposures: a review of the developmental contributions to obesity

In a recent study published in the Gastroenterology Clinics of North America Journal, researchers reviewed the latest studies on nutritional exposures during prenatal and early childhood stages.

Study: Developmental Contributions to Obesity: Nutritional Exposures in the First Thousand Days. Image Credit: komokvm/Shutterstock.com

Background

Obesity rates have increased globally in recent years, affecting all age groups, including children. Childhood obesity can lead to chronic adult diseases, such as type 2 diabetes and non-alcoholic fatty liver disease, as it continues into adulthood.

Prevention is crucial in addressing the challenges associated with obesity treatment and management. The "first thousand days" between conception and 24 months of age is a crucial period linked to the potential development of obesity during childhood and later adulthood.

Nutritional exposures encountered during infancy

Breastfeeding

Breastfeeding offers various health advantages for both the child and the mother, such as enhanced cognitive development and reduced risk of atopic diseases. Breast milk exposure during infancy may lead to improved dietary variety and quality.

Breastmilk can aid in healthy infant growth by providing nutritional cues like human milk oligosaccharides, which are natural prebiotics that impacts the gut microbiome of the infant's gut.

Breastfed children have lower rates of obesity compared to formula-fed children, as shown by several observational studies. Mothers who choose and are successful at breastfeeding may have different child, family, and maternal characteristics than those who do not.

An extensive randomized controlled trial discovered that there was no impact on adiposity during adolescence as a result of exclusive and prolonged breastfeeding.

The study only involved breastfeeding mothers, so the results may not apply to comparisons involving exclusive formula feeding or areas with higher obesity rates.

Complementary feeding

The optimal time to introduce complementary foods: The introduction of complementary feeding before four months of age is not recommended by experts as infants' motor development and gastrointestinal function are not yet fully developed.

Early introduction of complementary feeding before four months of age was linked to increased adiposity during mid-childhood in breastfed and formula-fed children.

Early introduction of complementary foods before four months was associated with higher truncal fat mass, skinfold thickness, and waist circumference in adolescence.

The American Academy of Pediatrics suggests introducing complementary foods to infants at around six months of age to avoid disrupting breastfeeding.

A meta-analysis concluded no significant differences in length, weight, and body mass index (BMI) z-scores estimated at 12 months and obesity/overweight at three years between formula-fed or breastfed infants who started complementary feeding at different ages.

The ideal composition of complementary feeding: A systematic review discovered that there was no significant association between the types and quantities of complimentary beverages and foods, such as meat, foods, and cereal with different fats, and growth, body composition, size, and/or the risk of overweight, obesity, or malnutrition. However, the study highlighted some key points:

• Sugar-sweetened beverages
  Children under the age of two years must avoid consuming sugar-sweetened beverages (SSBs) due to various reasons. Energy from sugary drinks can replace the energy from nutritious foods and beverages, which can lead to nutrient deficiencies. Limited evidence indicates that consuming SSBs during infancy and early childhood may increase the risk of childhood overweight. Early consumption of SSBs may lead to increased consumption of SSBs later in life, which could have negative health consequences.

• Fruit juice
  Increased fruit juice consumption at one year was linked to a higher intake of SSBs and a higher BMI-z-score during early and mid-childhood. Fruit juice could potentially be more detrimental to young children. A meta-analysis found that fruit juice consumption between ages one to six years was linked to a greater increase in BMI, while no such association was observed in children above six.

• Epigenetics
  It refers to alterations in gene activity that occur without changes in the deoxyribonucleic acid (DNA) sequence. Nutrition during early life can impact epigenetic variations associated with future health outcomes. Early pregnancy nutritional status has been associated with lasting epigenetic alterations in offspring.
   
• Microbiome
  The microbiome has been associated with various human diseases, such as obesity, throughout one's life. The maternal microbiome influences the infant microbiome during birth and potentially before birth.  Maternal obesity, along with poor diet, can alter breast milk composition, which can affect the infant's gastrointestinal microbiome. Changes in the infant's gut microbiota can impact metabolism programming. Furthermore, early-life epigenetic mechanisms, maternal dietary factors, and the gut microbiome may all play a role in contributing to the obesity of offspring in adulthood.

Conclusion

The study findings showed that early nutritional exposures could impact obesity risk and adiposity in later childhood and adolescence and may continue to affect an individual's health.

The researchers explored how maternal dietary quality and the composition and timing of complementary foods and beverages during infancy can affect the likelihood of childhood obesity.

Written by

Bhavana Kunkalikar

Bhavana Kunkalikar is a medical writer based in Goa, India. Her academic background is in Pharmaceutical sciences and she holds a Bachelor's degree in Pharmacy. Her educational background allowed her to foster an interest in anatomical and physiological sciences. Her college project work based on ‘The manifestations and causes of sickle cell anemia’ formed the stepping stone to a life-long fascination with human pathophysiology.