Research

Hormonal

Transitioning from a very-low-carbohydrate diet to a high-carbohydrate diet requires several weeks (approximately 5-9 weeks) for full glycemic adaptation, meaning a 3-day preparation period is insufficient for accurate diabetes screening in habitual low-carb dieters.

If you have been eating a very low-carb diet and plan to switch to a higher-carb diet (or undergo a diabetes test), do not expect your blood sugar to stabilize immediately. It can take 5 to 9 weeks for your body to fully adapt to processing carbohydrates again. If you are getting a diabetes screening, inform your doctor about your recent low-carb diet history, as a standard 3-day prep may yield a false positive.

GoodQualifiesHIGH confidence
Physiological adaptation from a low- to high-carbohydrate diet may require many weeks, with implications for the accuracy of diabetes tests... If 3 days of consuming ≥150 g/day carbohydrate were adequate preparation for diabetes screening, then no changes in measures of glucose homeostasis would be expected after the first week following transition to the high-carbohydrate diets. However, data from CGM indicate significant downward trends from week 2 to week 9...
Lisa T. Jansen et al. · Diabetes Care · 2022

Why this rating

Randomized controlled feeding trial with continuous glucose monitoring, though stopped early due to COVID-19.

Source

Prolonged Glycemic Adaptation Following Transition From a Low- to High-Carbohydrate Diet: A Randomized Controlled Feeding Trial

Lisa T. Jansen et al. · Diabetes Care · 2022

DOI 10.2337/dc21-1970

rct · n=77Cited 21×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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