What is the question? 

• The question is: What is the relationship between dietary patterns consumed and growth, body composition, and risk of obesity? The population of interest included infants and young children up to age 24 months, children and adolescents, adults and older adults, pregnancy, and postpartum. 

Why was this question asked? 

• This systematic review was conducted by the 2025 Dietary Guidelines Advisory Committee as part of the process to develop the Dietary Guidelines for Americans, 2025-2030. 

How was this question answered? 

• The Committee conducted a systematic review to answer this question with support from the USDA Nutrition Evidence Systematic Review team. This review updated existing reviews that were conducted by the 2020 Dietary Guidelines Advisory Committee, and as part of the Pregnancy and Birth to 24 Months Project and the Dietary Patterns Systematic Reviews Project. 

What is the answer to the question? 

Infants and young children up to age 24 months 

• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed by infants and young children up to age 24 months and growth, body composition, and risk of obesity because of substantial concerns with consistency. 

Children and adolescents

• Dietary patterns consumed by children and adolescents that are characterized by higher intakes of vegetables, fruit, legumes, nuts, whole grains, fish/seafood, dairy (low-fat, unsweetened) and lower intakes of red and processed meats, sugar-sweetened beverages, and sugar-sweetened or savory/salty snack foods are associated with favorable growth patterns, lower adiposity, and lower risk of obesity later in childhood and early adulthood. This conclusion statement is based on evidence graded as limited. 
• Dietary patterns consumed by children and adolescents that are characterized by higher intakes of red and processed meats, refined grains, sugar-sweetened beverages, sugar-sweetened or savory/salty snack foods, and fried potatoes, and lower intakes of vegetables, fruit, and whole grains are associated with unfavorable growth patterns, higher adiposity, and higher risk of obesity later in childhood and early adulthood. This conclusion statement is based on evidence graded as limited. 

Adults and older adults 

• Dietary patterns consumed by adults and older adults that are characterized by higher intakes of vegetables, fruits, legumes, nuts, whole grains, fish/seafood and lower intakes of meats (including red and processed meats), refined grains and sugar-sweetened foods and beverages are associated with lower adiposity (body fat, body weight, BMI, and/or waist circumference) and lower risk of obesity. These dietary patterns also included higher intakes of unsaturated fats and lower intakes of saturated fats and sodium. This conclusion statement is based on evidence graded as moderate. 

Pregnancy 

• Dietary patterns consumed during pregnancy may be associated with a lower risk of excessive gestational weight gain. These patterns tend to emphasize higher intakes of vegetables, fruits, legumes, nuts, whole grains, fish and dairy and lower intakes of added sugars. This conclusion statement is based on evidence graded as limited. 
• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed during pregnancy and risk of inadequate gestational weight gain because there are substantial concerns with consistency in the body of evidence. 

Postpartum 

• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed during postpartum and postpartum weight change because there are substantial concerns with consistency, precision, risk of bias and generalizability in the body of evidence. 

How up-to-date is this systematic review? 

• Conclusion statement(s) from this review are based on articles published between January 1980 and May 2023.

Background 

• This systematic review was conducted by the 2025 Dietary Guidelines Advisory Committee as part of the process to develop the Dietary Guidelines for Americans, 2025-2030. The U.S. Departments of Health and Human Services (HHS) and Agriculture (USDA) appointed the 2025 Dietary Guidelines Advisory Committee (Committee) in January 2023 to review evidence on high priority scientific questions related to diet and health. Their review forms the basis of their independent, science-based advice and recommendations to HHS and USDA, which is considered as the Departments develop the next edition of the Dietary Guidelines. As part of that process, the Committee conducted a systematic review with support from the USDA Nutrition Evidence Systematic Review (NESR) team to answer the following question: What is the relationship between dietary patterns consumed and growth, body composition, and risk of obesity? This is an update to existing systematic reviews that were conducted by the 2020 Dietary Guidelines Advisory Committee, and as part of the Pregnancy and Birth to 24 Months Project and the Dietary Patterns Systematic Reviews Project.

Methods 

• The Committee conducted a systematic review using the methodology of the USDA NESR team. The Committee first developed a protocol. The intervention/exposure and comparators for all populations were consumption of a dietary pattern compared to a different dietary pattern and different adherence to/consumption levels of a dietary pattern. The outcomes were measures of growth, body composition, and risk of obesity in all populations. Additional criteria were established to include: a) randomized or non-randomized controlled trial, prospective or retrospective cohort, or nested case-control designs, b) published in English in peer-reviewed journals, c) studies in countries classified as high or very high on the Human Development Index, and d) participants with a range of health statuses. The review excluded studies that exclusively enrolled participants who were being treated for a disease. 
• NESR librarians performed the literature search in PubMed, Embase, CINAHL, and Cochrane to identify articles published between October 2019 and May 2023. Two NESR analysts independently screened all electronic results and the reference lists of included articles based on the pre-determined criteria. The results of this search were combined with eligible included articles from the existing reviews. 
• NESR analysts extracted data, from each included article, with a second analyst verifying accuracy of the extraction. Two NESR analysts independently conducted a formal risk of bias assessment, by study design, for each included article, then reconciled any differences in the assessment. The Committee qualitatively synthesized evidence from all included articles in the updated literature search and existing systematic reviews according to the synthesis plan, with attention to the overarching themes or key concepts from the findings, similarities and differences between studies, and factors that may have affected the results. The Committee developed [a] conclusion statement[s] by starting with the conclusion from the existing review and determining whether and what updates were needed based on the newly published evidence. After establishing the need for updating the review, the Committee then developed conclusion statements and graded the strength of evidence based on its consistency, precision, risk of bias, directness and generalizability. 

Results

Infants and young children up to age 24 months 

Conclusion statement and grade 

• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed by infants and young children up to age 24 months and growth, body composition, and risk of obesity because of substantial concerns with consistency. (Grade: Grade Not Assignable) 

Summary of the evidence 

• Eighteen articles met inclusion for this review in infants and young children. One article came from a randomized controlled trial design and 17 from prospective cohort studies. 
• The 2025 Committee was not able to draw a conclusion due to critical limitations in the body of evidence. 

Children and adolescents 

Conclusion statement and grade 

• Dietary patterns consumed by children and adolescents that are characterized by higher intakes of vegetables, fruit, legumes, nuts, whole grains, fish/seafood, and dairy (low-fat, unsweetened) and lower intakes of red and processed meats, sugar-sweetened beverages, and sugar-sweetened or savory/salty snack foods are associated with favorable growth patterns, lower adiposity, and lower risk of obesity later in childhood and early adulthood. This conclusion statement is based on evidence graded as limited. (Grade: Limited) 
• Dietary patterns consumed by children and adolescents that are characterized by higher intakes of red and processed meats, refined grains, sugar-sweetened beverages, sugar-sweetened or savory/salty snack foods, and fried potatoes, and lower intakes of vegetables, fruit, and whole grains are associated with unfavorable growth patterns, higher adiposity, and higher risk of obesity later in childhood and early adulthood. This conclusion statement is based on evidence graded as limited. (Grade: Limited) 

Summary of the evidence 

• Sixty-two articles met inclusion for this review in children and adolescents. Three articles came from randomized controlled trials and 59 from prospective cohort studies.
• The direction of results and effect size differed across studies. 
• The size of study groups was small and variance around effect estimates was wide across studies. 
• Some studies were designed and conducted well. 
• The populations and outcome measures directly represented those of interest in the review, but some dietary patterns examined did not. 
• The evidence applies to the U.S. population, except participants and dietary patterns examined in some studies may not be applicable. 

Adults and older adults 

Conclusion statement and grade 

• Dietary patterns consumed by adults and older adults that are characterized by higher intakes of vegetables, fruits, legumes, nuts, whole grains, and fish/seafood and lower intakes of meats (including red and processed meats), refined grains and sugar-sweetened foods and beverages are associated with lower adiposity (body fat, body weight, BMI, and/or waist circumference), and lower risk of obesity. These dietary patterns also included higher intakes of unsaturated fats and lower intakes of saturated fats and sodium. This conclusion statement is based on evidence graded as moderate. (Grade: Moderate)

Summary of the evidence 

• The body of evidence includes 106 articles (26 from randomized controlled trials; 79 from prospective cohort studies; 1 from a retrospective cohort study) published since 2019 that met inclusion for this review in adults and older adults. 
• The direction of results and effect size were similar across studies. 
• The size of study groups was large across studies. Variance around effect estimates was narrow across studies. 
• Some studies were designed and conducted well. 
• The populations, dietary patterns, and outcome measures that were examined directly represent those of interest in this review. 
• The evidence applies to the U.S. population, except may not be applicable for select participants. 

Pregnancy 

Conclusion statement and grade 

• Dietary patterns consumed during pregnancy may be associated with a lower risk of excessive gestational weight gain. These patterns tend to emphasize higher intakes of vegetables, fruits, legumes, nuts, whole grains, fish and dairy and lower intakes of added sugars. This conclusion statement is based on evidence graded as limited. (Grade: Limited) 
• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed during pregnancy and risk of inadequate gestational weight gain because there are substantial concerns with consistency in the body of evidence. (Grade: Grade Not Assignable) 

Summary of the evidence 

• The body of evidence includes 22 articles that met inclusion for this review during pregnancy. Three articles came from randomized controlled trials, 18 from prospective cohort studies, and 1 from a retrospective cohort design. 
• The direction of results and size of effects were too different across studies. 
• The size of study groups was small and variance around effect estimates was wide across studies. 
• Few studies were designed and conducted well. 
• The populations, dietary patterns, and outcome measures examined do not directly represent those of interest in this review. 
• The evidence may not apply to the U.S. population. 

Postpartum 

Conclusion statement and grade 

• A conclusion statement cannot be drawn about the relationship between dietary patterns consumed during postpartum and postpartum weight change because there are substantial concerns with consistency, precision, risk of bias and generalizability in the body of evidence. (Grade Not Assignable) 

Summary of the evidence 

• The body of evidence includes 7 articles that met inclusion for this review during postpartum. One article came from a randomized controlled trial and 6 from prospective cohort studies. 
• The 2025 Committee was not able to draw a conclusion due to critical limitations in the body of evidence

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Suggested citation: Hoelscher DM, Tobias D, Deierlein A, Gardner C, Giovannucci E, Anderson CAM, Booth S, Fung T, Raynor H, Stanford FC, Talegawkar S, Taylor C, English LK, Raghavan R, Reigh N, Higgins M, Nevins J, Scinto-Madonich S, Callahan EH, Fultz A, Huang, S, Butera G, Terry N, Obbagy J. Dietary Patterns and Growth, Body Composition, and Risk of Obesity: A Systematic Review. November 2024. U.S. Department of Agriculture, Food and Nutrition Service, Center for Nutrition Policy and Promotion, Nutrition Evidence Systematic Review. Available at: https://doi.org/10.52570/NESR.DGAC2025.SR01