Originally developed in the 1980s, the glycemic index (GI) was intended to differentiate glycemic responses among foods that contained the same amount of carbohydrate. It ranks carbohydrate-containing foods by how quickly they raise blood glucose relative to a reference food, usually pure glucose or white bread. In research settings, participants consume a precise amount of carbohydrate from a single food after fasting (occasionally a mixed meal), and glucose responses are measured over time. Foods are then categorized as low GI (55 or less), moderate GI (56–69), or high GI (70 or higher). Numerous studies have link lower-glycemic-index eating patterns with reduced diabetes risk, improved glycemic management, reduced cardiovascular risk, and better satiety. A 2021 systematic review of 29 clinical trials involving adults with type 1 and type 2 diabetes found that low glycemic eating patterns modestly improved A1c levels by 0.31% compared with higher glycemic load diets.¹ The Dyslipidemia guidelines recommend improving carbohydrate quality, not just quantity, through higher-fiber, whole-grain, and lower glycemic index fruit, vegetable, and carbohydrate sources.² A 2024 meta-analysis, which included over 100,000 participants, confirmed that low-GI dietary patterns were associated with reduced incidence of diabetes, cardiovascular disease, diabetes-related cancers, and all-cause mortality, but also noted that these protective associations were similar to those observed with increased intake of fiber and whole grains.³ This sentiment is emphasized in the 2026 ADA Standards of Care statement that a “low GI or low GL is synonymous with higher-fiber eating patterns”.⁴