Trends in dietary patterns over the last decade and their association with long-term mortality in general US populations with undiagnosed and diagnosed diabetes

Background Dietary management plays an important role in diabetes care, while the trends in dietary patterns over the last decade in US adults with diagnosed and undiagnosed diabetes remain unknown. This study aims to estimate the dietary patterns over the last decade by baseline diabetes diagnoses and explore their association with long-term prognosis. Methods Participants’ data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2007–2018, which were divided into three groups according to the diabetes diagnosis: without diabetes, undiagnosed diabetes, and diagnosed diabetes. Healthy eating index (HEI) and dietary inflammatory index (DII) were used to evaluate dietary patterns. Survival analyses were adopted to estimate the association between HEI/DII scores and long-term all-cause mortality and cause-specific mortality. Results The prevalence of diabetes was increasing among US adults over the last decade. HEI scores of all three groups presented a downward trend in recent years. Participants with undiagnosed diabetes (weighted mean: 50.58, 95% CI: 49.79, 51.36) got significantly lower HEI score in comparison to participants with diagnosed diabetes (weighted mean: 51.59, 95% CI: 50.93, 52.25). Compared with participants without diabetes, participants in the undiagnosed or diagnosed diabetes group had higher DII scores, indicating a higher dietary inflammatory potential. Survival analysis found a significant association between HEI scores and all-cause mortality and death of heart diseases. Similar correlation was observed in DII scores. Conclusions Along with the growth in diabetes prevalence in the US, dietary management of people with diabetes is decreasing. The management of US adults’ diets needs special attention, and dietary inflammatory potential may be considered in the dietary intervention.