When to check blood sugar after eating with gestational diabetes

Check 1 hour or 2 hours after the meal, whichever your clinic asked for, counted from when you start eating, not when you finish. Most people with gestational diabetes also check once when they wake up, before eating (fasting).

Last reviewed 2026-09-21. Written by the First Fork team from the published guidelines listed below; not reviewed by a clinician. This page is not medical advice.

1 hour or 2 hours?

Both are used. The American Diabetes Association's 2026 Standards of Care set goals for either a 1-hour or a 2-hour check after meals.¹ The ADA's patient guidance says to check when you wake, before you eat, and one or two hours after meals, and to ask your care team which times are right for you.² NICE in the UK advises a fasting check and a 1-hour after-meal check every day for gestational diabetes managed by diet and exercise or by tablets.³

There is no “better” one to pick yourself. Your clinic chose one, and its targets match that timing.

From the first bite, not the last

The clock starts when you start eating. The ADA's guide to diabetes in pregnancy, summarising ACOG, describes the check as 1 or 2 hours after the start of the meal.⁴ A slow dinner that takes 40 minutes still means the check is 1 hour after the first bite. If your clinic counts differently, follow your clinic.

A typical day

That is four checks a day. People on insulin are often asked to check more often, for example before meals and at bedtime.³

How not to miss the window

• Set a timer at the first bite, not when you sit down or when you finish.
• Write down the start time next to the reading. The free printable log has a column for it.
• If you check late, write the actual time. Your clinic needs to know it was a 75-minute reading, not a 60-minute one.

Questions

Do I start timing when I start or finish eating?

When you start eating. Guidance describes the check as 1 or 2 hours after the start of the meal. If your clinic told you something else, follow your clinic.

What if I snack between meals?

Ask your clinic. Most schedules only ask for checks after the main meals and a fasting check.

What if I check at 1 hour 15 minutes?

Write the real time next to the reading so your team can read it correctly.

Sources

1. American Diabetes Association. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes—2026. Diabetes Care 2026;49(Suppl. 1):S321. https://pmc.ncbi.nlm.nih.gov/articles/PMC12690181/
2. American Diabetes Association. Diabetes and Pregnancy (patient page). https://diabetes.org/living-with-diabetes/pregnancy
3. NICE guideline NG3. Diabetes in pregnancy: management from preconception to the postnatal period (recommendations 1.3.3–1.3.6). https://www.nice.org.uk/guidance/ng3/chapter/Recommendations
4. American Diabetes Association. Glycemic Goals and Assessment during Pregnancy (Chapter 3), in Medical Management of Pregnancy Complicated by Diabetes. https://diabetesjournals.org/books/book/46/chapter/5050222/Glycemic-Goals-and-Assessment-during-Pregnancy

See a mistake, or something unclear? Report a problem