What is the question?

• The question is: What is the relationship between the types and amounts of complementary foods and beverages consumed and developmental milestones? 

What is the answer to the question?

• There is insufficient evidence to draw a conclusion about the relationships between types and amounts of complementary foods and beverages consumed and developmental milestones. 

Why was this question asked? 

• This important public health question was identified and prioritized as part of the U.S. Department of Agriculture and Department of Health and Human Services Pregnancy and Birth to 24 Months Project.

How was this question answered? 

• A team of Nutrition Evidence Systematic Review staff conducted a systematic review in collaboration with a group of experts called a Technical Expert Collaborative

What is the population of interest? 

• Generally healthy infants and toddlers who were fed complementary foods and beverages from ages 0-24 months and had developmental milestones examined through 18 years of age

What evidence was found? 

• This review includes eight studies published since 1980, including three randomized controlled trials and five prospective cohort studies. 
• These studies compared types and/or amounts of complementary foods and beverages (CFB) consumed and developmental milestones during childhood through 18 years of age.
• Complementary foods and beverages were defined as foods and/or beverages other than human milk or infant formula (liquids, semisolids, and solids) provided to an infant or young child to provide nutrients and energy
• The studies varied in terms of the types and/or amounts of complementary foods and beverages examined, which included dietary patterns consumed during the complementary feeding period, meat and/or fortified-cereal intake, and foods with differing levels of DHA or phytate
• Different types of developmental milestone outcomes were measured between 4 months and 8.5 years of age, including:
  • communication development such as sentence repetition
  • cognitive development such as mental development index scores
  • motor development such as psychomotor development index scores
  • neurological development such as cortical processing
• There are limitations in the evidence as follows: an inadequate number of studies that were comparable in terms of design, and variation in the types of complementary foods and beverages examined, how and when developmental milestones outcomes were assessed, and reported results

How up-to-date is this systematic review? 

• This review includes literature from 01/1980 to 07/2016.

Background

• The goal of this systematic review was to examine the following question: What is the relationship between types and amounts of complementary foods and beverages (CFB) consumed and developmental milestones? 
• Systematic reviews were conducted as part of the U.S. Department of Agriculture and Department of Health and Human Services Pregnancy and Birth to 24 Months Project. 
• Complementary feeding is the process that starts when human milk or infant formula is complemented by other foods and beverages, beginning during infancy and typically continuing to 24 months of age. 

Conclusion Statement and Grade

• There is insufficient evidence to draw a conclusion about the relationships between types and amounts of complementary foods and beverages consumed and developmental milestones.
  
  Grade: Grade Not Assignable

Methods 

• This systematic review was conducted by a team of staff from the Nutrition Evidence Systematic Review in collaboration with a Technical Expert Collaborative. 
• A literature search was conducted using 4 databases (PubMed, Cochrane, Embase, and CINAHL) to identify articles that evaluated the intervention or exposure of types and amounts of CFB consumed and the outcome of developmental milestones. A manual search was conducted to identify articles that may not have been included in the electronic databases searched. Articles were screened by two authors independently for inclusion based on pre-determined criteria. 
• Data extraction and risk of bias assessment were conducted for each included study, and both were checked for accuracy. The body of evidence was qualitatively synthesized to inform development of a conclusion statement(s), and the strength of evidence was graded using pre-established criteria evaluating the body of evidence on internal validity/risk of bias, adequacy, consistency, impact, and generalizability.

Summary of Evidence

• This review includes eight studies published since 1980 that examined the relationship between consuming different types and/or amounts of CFB and developmental milestones during childhood through 18 years of age, including three randomized controlled trials and five prospective cohort studies. 
• The studies varied in terms of the types and/or amounts of CFB examined, which included dietary patterns consumed during the complementary feeding period, meat and/or fortified-cereal intake, and foods with differing levels of DHA or phytate
• Different types of developmental milestone outcomes were measured between 4 months and 8.5 years of age, including:
  • Communication (e.g., sentence repetition)
  • Cognitive (e.g., mental development index)
  • Motor (e.g., psychomotor development index)
  • Neurological (e.g., cortical processing) 
• Three articles from two observational studies identified positive associations between dietary patterns emphasizing vegetables and meats during the complementary feeding period, and intelligence quotient (IQ) between ages 4-8.5y. However, a conclusion could not be drawn due to low generalizability and heterogeneity in exposures, observed effects, and potential confounding
• Because there was substantial variation in how studies were designed, it is difficult to compare and contrast the reported results.
• No conclusion regarding the relationship between types and/or amounts of CFB and developmental milestones could be drawn due to an inadequate number of studies that were comparable in terms of design, the types of CFB examined, how and when developmental milestones outcomes were assessed, and reported results.