Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jun 18;17(12):2026.
doi: 10.3390/nu17122026.

Biological vs. Chronological Overnight Fasting: Influence of Last Evening Meal on Morning Glucose in Dysglycemia

Affiliations

Biological vs. Chronological Overnight Fasting: Influence of Last Evening Meal on Morning Glucose in Dysglycemia

Diana A Diaz-Rizzolo et al. Nutrients. .

Abstract

Background/Objectives: Nocturnal glucose regulation is a critical but underexplored determinant of next-day fasting glucose (FG), particularly in individuals with dysglycemia. This study examined the role of glucose levels after the last eating occasion (LEO) and during the overnight fast in predicting FG, considering the potential influence of carbohydrate content in LEO and insulin sensitivity. Methods: In a controlled 24 h protocol, 33 adults (50-75 years) with prediabetes or diet-controlled type 2 diabetes followed a standardized feeding schedule with meals at fixed times, including a LEO at 10:00 p.m. Continuous glucose monitoring was used to assess glucose during the 3 h postprandial period (LEO-PPGR) and two fasting intervals: chronological overnight fast (COF) and biological overnight fast (BOF). Associations with FG were tested using general linear models, adjusting for carbohydrate intake and insulin sensitivity (Matsuda index). Results: Glucose responses during LEO-PPGR-assessed by mean glucose, peak, and AUC-were strongly correlated with FG the next morning (r = 0.704, 0.535, and 0.708, p < 0.001). Similarly, glucose levels during COF and BOF were also correlated with FG (r = 0.878, p < 0.001 for both), but these associations weakened after adjustment for LEO carbohydrate content. The Matsuda index was positively correlated with glucose in all three periods (p < 0.05), yet its inclusion in the model attenuated all previously significant associations with FG. Conclusions: These findings suggest that the glycemic response to the last meal and subsequent overnight glucose levels contribute to next-day FG, but their impact is modulated by carbohydrate content and individual insulin sensitivity. Understanding nocturnal glycemic dynamics may inform strategies for improving metabolic outcomes in dysglycemia.

Keywords: carbohydrate; evening meal; fasting glucose; insulin resistance; insulin sensitivity; last eating occasion; overnight glucose; postprandial glucose response; prediabetes; type 2 diabetes.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Study design and analyzed variables. BOF: biological overnight fast; COF: chronological overnight fast; FG: fasting glucose; LEO: last eating occasion; LEO-PPGR: fixed 3 h post prandial glucose response following meal. CGM: continuous glucose monitor glucose values: continuous black line.
Figure 2
Figure 2
Association between mean glucose during chronological overnight fast (COF) and next day fasting glucose (FG) adjusted by LEO carbohydrate content (n = 19). (A) Carbohydrates in grams, (B) carbohydrates in percentage.
Figure 2
Figure 2
Association between mean glucose during chronological overnight fast (COF) and next day fasting glucose (FG) adjusted by LEO carbohydrate content (n = 19). (A) Carbohydrates in grams, (B) carbohydrates in percentage.
Figure 3
Figure 3
Association between mean glucose during biological overnight fast (BOF) and next-day fasting glucose (FG) adjusted by LEO carbohydrate content (n = 19). (A) Carbohydrates in grams, (B) carbohydrates in percentage.

References

    1. American Diabetes Association Professional Practice Committee. ElSayed N.A., Aleppo G., Bannuru R.R., Bruemmer D., Collins B.S., Ekhlaspour L., Gaglia J.L., Hilliard M.E., Johnson E.L., et al. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2024. Diabetes Care. 2023;47((Suppl. S1)):S20–S42. doi: 10.2337/dc24-s002. - DOI - PMC - PubMed
    1. Gannon M.C., Nuttall F.Q., Westphal S.A., Fang S., Ercan-Fang N. Acute metabolic response to high-carbohydrate, high-starch meals compared with moderate-carbohydrate, low-starch meals in subjects with type 2 diabetes. Diabetes Care. 1998;21:1619–1626. doi: 10.2337/diacare.21.10.1619. - DOI - PubMed
    1. Arauz-Pacheco C., Clements G., Cercone S., Brinkley L., Raskin P. Effects of a large supper on glucose levels the following morning in patients with type 2 diabetes. J. Diabetes Its Complicat. 1998;12:61–64. doi: 10.1016/S1056-8727(97)00073-1. - DOI - PubMed
    1. Mason I.C., Qian J., Adler G.K., Scheer F.A.J.L. Impact of circadian disruption on glucose metabolism: Implications for type 2 diabetes. Diabetologia. 2020;63:462–472. doi: 10.1007/s00125-019-05059-6. - DOI - PMC - PubMed
    1. Basu R., Barosa C., Jones J., Dube S., Carter R., Basu A., Rizza R.A. Pathogenesis of Prediabetes: Role of the Liver in Isolated Fasting Hyperglycemia and Combined Fasting and Postprandial Hyperglycemia. J. Clin. Endocrinol. Metab. 2013;98:E409–E417. doi: 10.1210/jc.2012-3056. - DOI - PMC - PubMed

LinkOut - more resources