ABSTRACT
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 USDA’s Nutrition Evidence Systematic Review (NESR) team to answer the following question: What is the relationship between sugar-sweetened beverage consumption and risk of type 2 diabetes?
Methods
The Committee conducted a systematic review using the methodology of the USDA NESR team. The Committee first developed a protocol. The intervention/exposure was sugar-sweetened beverage consumption in infants and young children up to age 24 months, children, adolescents, adults, and older adults, the comparators were consumption of a different amount of sugar-sweetened beverages (including no consumption and versions diluted with water), water, or low- and no-calorie sweetened beverages, and the outcomes were fasting blood glucose, fasting insulin, glucose tolerance/insulin resistance, hemoglobin A1C, prediabetes, and risk of type 2 diabetes in infants and young children, children, adolescents, adults, and older adults. Additional inclusion criteria were established for the following study characteristics: a) use randomized or non-randomized controlled trial, prospective or retrospective cohort, nested case-control, or Mendelian randomization study designs, b) be published in English in peer-reviewed journals, c) be from countries classified as high or very high on the Human Development Index, and d) enroll participants with a range of health statuses. The review excluded intervention studies less than 12-week duration for hemoglobin A1C, prediabetes, and type 2 diabetes, and intervention studies less than 4-week study duration for fasting blood glucose, fasting insulin, and glucose tolerance/insulin resistance.
NESR librarians conducted a literature search in PubMed, Embase, CINAHL, and Cochrane to identify articles published between January 2000 and January 2024. Two NESR analysts independently screened all electronic results, and the reference lists of included articles based on the pre-determined criteria.
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 the evidence, according to the synthesis plan, with attention given 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 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 sugar-sweetened beverage consumption by infants and young children up to age 24 months and risk of type 2 diabetes because there is no evidence available.
(Grade: Grade Not Assignable)
Summary of the evidence:
• No articles met the inclusion criteria for this review in infants and young children up to age 24 months.
• The Committee was not able to draw a conclusion because no evidence was available.
Children and adolescents
Conclusion statement and grade: A conclusion statement cannot be drawn about the relationship between sugar-sweetened beverage consumption by children and adolescents and risk of type 2 diabetes because of substantial concerns with directness in the body of evidence. (Grade: Grade Not Assignable)
Summary of the evidence:
• Five articles from prospective cohort study designs met the inclusion criteria for this review in children and adolescents.
• The Committee was not able to draw a conclusion due to substantial concerns with directness, particularly with no studies examining the primary outcome of interest, and some concerns with risk of bias for potential confounding.
Adults and older adults
Conclusion statement and grade: Sugar-sweetened beverage consumption by adults and older adults may be associated with higher risk of type 2 diabetes. This conclusion statement is based on evidence graded as moderate. (Grade: Moderate)
Summary of the evidence:
• Forty-three articles met the inclusion criteria for this review in adults and older adults. Six were randomized controlled trials, 1 was a nested case control study, and 36 were prospective cohort studies.
• The direction of results and size of effects were similar across studies.
• The size of study groups was large across studies. Most studies examined enough cases of type 2 diabetes. Variation around the effect estimates were narrow across studies.
• Some studies were designed and conducted well.
• The populations, interventions/exposures, comparators, and outcomes that were examined directly represent those of interest in this review.
• The evidence applies to the U.S. population but may not apply to diverse subgroups based on socioeconomic position and race and/or ethnicity.