This document describes a systematic review conducted to answer the following question: What is the relationship between types and amounts of complementary foods and beverages (CFB) and food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis? This systematic review was conducted as part of the Pregnancy and Birth to 24 Months (P/B-24) Project by USDA’s Nutrition Evidence Systematic Review (NESR).

The purpose of the P/B-24 Project was to conduct a series of systematic reviews on diet and health for women who are pregnant and for infants and toddlers from birth to 24 months of age. This project was a joint initiative led by USDA and HHS, and USDA’s NESR carried out all of the systematic reviews. A Federal Expert Group (FEG), a broadly representative group of Federal researchers and program leaders, also provided input throughout the P/B-24 Project. More information about the P/B-24 Project has been publishedⁱⁱ and is available on the NESR website: https://nesr.usda.gov/project-specific-overview-pb-24-0.

NESR, formerly known as the Nutrition Evidence Library (NEL), specializes in conducting food- and nutrition-related systematic reviews using a rigorous, protocol-driven methodology. To conduct each P/B-24 systematic review, NESR’s staff worked with a Technical Expert Collaborative (TEC), which is a group of 7–8 leading subject matter experts.

NESR’s systematic review methodology involves developing and prioritizing systematic review questions, searching for and selecting studies, extracting and assessing the risk of bias of data from each included study, synthesizing the evidence, developing a conclusion statement, grading the evidence underlying the conclusion statement, and recommending future research. A detailed description of the methodology used in conducting systematic reviews for the P/B-24 Project has been publishedⁱⁱⁱ and is available on the NESR website: https://nesr.usda.gov/pb-24-project-methodology-0. In addition, starting on page 112, this document includes details about the methodology as it was applied to the systematic review described herein. An analytic framework that illustrates the overall scope of the question, including the population, the interventions and/or exposures, comparators, and outcomes of interest, is found on page 112. In addition, the literature search plan that was used to identify studies included in this systematic review is found on page 112.

Footnotes

ii

Stoody EE, Spahn JM, Casavale KO. The Pregnancy and Birth to 24 Months Project: a series of systematic reviews on diet and health. Am J Clin Nutr. 2019;109(7):685S–97S. doi: 10.1093/ajcn/nqy372. [PubMed: 30982878] [CrossRef]

iii

Obbagy JE, Spahn JM, Wong YP, Psota TL, Spill MK, Dreibelbis C, et al. Systematic review methodology used in the Pregnancy and Birth to 24 Months Project. Am J Clin Nutr. 2019;109(7):698S–704S. doi: 10.1093/ajcn/nqy226. [PubMed: 30445449] [CrossRef]