Obesity reflects excessive fat deposits. At-risk individuals are guided by healthcare professionals to eat fewer calories and exercise more, often using body mass index (BMI; weight/height²) thresholds for screening and to guide progress and prognosis. By conducting a mini-narrative review of original articles, websites, editorials, commentaries, and guidelines, we sought to place BMI in the context of its appropriate use in population health, clinical screening, and monitoring in clinical care. The review covers studies and publications through 2023, encompassing consensus reviews and relevant literature. Recent consensus reviews suggest that BMI is a valuable tool for population surveys and primary healthcare screening but has limitations in predicting the risk of chronic diseases and assessing excess fat. BMI can guide nutritional and exercise counseling, even if it is inadequate for reliable individual risk prediction. BMI cut-offs must be reconsidered in populations of varying body build, age, and/or ethnicity. Since BMI-diagnosed overweight persons are sometimes physically and physiologically fit by other indicators, persons who are overweight on BMI should be more fully evaluated, diagnosed, and monitored with combined anthropometric and performance metrics to better clarify risks. The use of combined anthropometric and performance metrics involves integrating measurements of body composition with assessments of physical function and fitness to provide a more comprehensive evaluation of an individual’s health and fitness status. Eligibility for bariatric surgery or semaglutide satiety/appetite-reduction medications should not be determined by BMI alone. Awareness of the advantages and limitations of using BMI as a tool to assess adult obesity can maximize its appropriate use in the context of population health and in rapid clinical screening and evaluation.

Obesity and chronic inflammation are associated with an elevated risk of diverticulitis. However, the underlying mechanisms, particularly the role of circulating metabolites are not well understood. We derived metabolomic signatures of metabolic dysfunction (body mass index, waist circumference, C-peptide, and adiponectin) and inflammation (C-reactive protein, interleukin 6, and tumor necrosis factor receptor superfamily 1B). We then predicted metabolomic signatures among 7888 participants who were free of diverticulitis at blood collection in Nurses' Health Study (NHS), NHSII, and Health Professional Follow-up Study (HPFS) and evaluated their association with risk of diverticulitis incidence, recurrence, and surgery. Metabolomic signatures explained 32% of the variation in the metabolic dysfunction markers and 29% of the variation in inflammation markers. Both signatures were significantly associated with an increased risk of diverticulitis. The multivariable-adjusted hazard ratio (HR) for incident diverticulitis comparing participants in the highest quartile to those in the lowest was 1.97 (95% confidence interval [CI]: 1.52-2.54; P-trend<0.0001) for the metabolic dysfunction signature and 1.40 (95% CI: 1.08-1.81; P-trend = 0.02) for the inflammation signature. Metabolic dysfunction signature was additionally associated with an increased risk of diverticulitis recurrence (extreme-quartile HR: 1.80; 95% CI: 1.10-2.96; P-trend = 0.004) and surgery requirement (HR: 2.99; 95% CI: 1.56-5.70; P-trend = 0.005). Both metabolomic signatures of metabolic dysfunction and inflammation were significantly associated with incident diverticulitis. The metabolic dysfunction signature showed a more robust association with diverticulitis recurrence and surgery requirement. Our results suggest a role of circulating metabolites in metabolic and inflammatory pathways in diverticulitis pathogenesis. This study was supported by grants from the National Institutes of Health (UM1 CA186107, R01 CA49449, U01CA176726, R01 CA67262, U01 CA167552). ATC is an American Cancer Society Research Professor. WM is supported by the National Institutes of Health (K01DK135854-01A1), American Gastroenterological Association (AGA2021-13-01), and MGH Claflin Distinguished Scholar Award. ATC, ELG, and LLS are supported by National Institutes of Health (R01 DK101495). MD is supported by the National Institutes of Health/National Cancer Institute (NIH/NCI K00CA274714, K99CA297022). LLS is supported by National Institute of Health (NIDDK 1 R01DK131694). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.