TOPLINE: Higher energy intake and glycemic load in the late morning are associated with a reduced risk of type 2 diabetes (T2D) among Hispanic/Latino adults.
METHODOLOGY: Glucose tolerance typically peaks in the morning and declines throughout the afternoon and evening in individuals without diabetes. Researchers conducted a prospective cohort study involving 8,868 Hispanic/Latino adults (mean age: 38.7 years; 51.5% women) without diabetes across four U.S. communities from 2008 to 2011, with a follow-up clinic examination conducted between 2014 and 2017. Meal timing was categorized into five periods: Early morning (6:00-8:59 AM), late morning (9:00-11:59 AM), afternoon (12:00-5:59 PM), evening (6:00-11:59 PM), and night (12:00-5:59 AM). Participants’ energy intake and glycemic load for each period were assessed at baseline using two 24-hour dietary recalls. Incident diabetes cases were identified through annual follow-up calls or at the second clinic examination.
TAKEAWAY: Each 100-kcal increment in energy intake and each 10-unit increment in glycemic load during the late morning was associated with a 6% and 7% lower risk of T2D, respectively (both P = .001), independent of total energy intake, diet quality, and other confounding factors. No significant associations were found between energy intake or glycemic load during early morning, afternoon, evening, or night meal timings and diabetes risk. Additionally, substituting 100 kcal of energy intake from early morning, afternoon, or evening with late-morning equivalents was linked to a 5% lower risk for diabetes (all P < .05). Similarly, substituting 10 units of energy-adjusted glycemic load from other meal times with late-morning equivalents yielded a 7%-9% lower risk for diabetes (all P < .05).
IN PRACTICE: “Our findings further enhance the existing literature by demonstrating the potential long-term benefits of eating in alignment with the diurnal rhythm of glucose tolerance for diabetes prevention,” stated the authors.
SOURCE: The study was led by Jin Dai, PhD, from the Fielding School of Public Health at the University of California, Los Angeles, and was published online in Diabetes Care.
LIMITATIONS: The study’s reliance on only two 24-hour self-reported dietary recalls may have introduced measurement errors. The self-reported nature of diabetes diagnoses could lead to outcome misclassification. Additionally, the relatively short follow-up period may have introduced reverse causation bias. The findings primarily apply to this diabetes subtype, as most participants had T2D.
