Inflammation is intimately linked to a variety of chronic diseases and precursors to these diseases, including metabolic syndrome (MetS). Because carbohydrate foods are associated with glycemic and insulin responses and may be linked to levels of inflammation and insulin resistance (IR), both glycemic index (GI) and glycemic load (GL) have been postulated as being associated with inflammation and MetS. This narrative review will address the role of GI and GL on various indicators of inflammation, IR and MetS, and their role in potentially reducing the risk of or mitigating these conditions. This review is drawn from a larger narrative review conducted for the Wheat Foods Council using MEDLINE entries. The literature to date shows mixed results, with some studies indicating that lowering dietary GI or GL reduces markers of inflammation or severity IR and can decrease the risk of or improve some of the indicators of MetS. One potential reason for variability is that diets with low and high GI and GL are often altered in many aspects, not just GI or GL. These multiple dietary changes create confounding because foods that comprise low GI or GL diets are often high in fiber, micronutrients, and phytochemicals. Another potential reason is due to differences in subject characteristics. Studies appear to have different outcomes because of glucose tolerance, gender, body weight, age, race, and ethnicity of the subjects. Subjects of certain ethnic minorities and those with impaired glucose tolerance or increased body mass index, compared with those without these conditions, may be more adversely affected by diets high in GI or GL and show associations with increased markers of inflammation, IR and MetS. More research is needed to clarify the impact of GI and GL on markers of inflammation, insulin sensitivity and resistance, and indicators of MetS.