2-hour post-meal glucose optimal range and reference range

Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026

Sera's bands for 2-hour post-meal glucose:

Optimal 70 – 120 mg/dL (3.9 – 6.7 mmol/L); sufficient 70 – 140 mg/dL (3.9 – 7.8 mmol/L); out of range below 70 or above 140 mg/dL.

Evidence grade: Functional / longevity target. A narrower target in common use in functional, integrative, preventive and longevity practice. It is not a universally validated diagnostic range.

At Sera's last range review a change to this band was proposed and held, because the evidence for it was thin, so the band is unchanged. The note below says where it matches published intervals and where it does not.

All units

Unit	Optimal	Sufficient	Out of range
mg/dL	70 – 120	70 – 140	below 70 or above 140
mmol/L	3.9 – 6.7	3.9 – 7.8	below 3.9 or above 7.8

What the evidence says

No guideline sets a 2-hour post-meal range for adults without diabetes. The 140 mg/dL (7.8 mmol/L) edge is borrowed from the 2-hour value of the glucose tolerance test, which uses a standard glucose drink, not a meal; sensor data from healthy adults agree with it in practice, with glucose above 140 for about 2% of the day. The optimal edge of 120 mg/dL (6.7 mmol/L) is a functional target with no published source. A result below 70 mg/dL (3.9 mmol/L) is flagged as low, as it is for fasting glucose: low blood sugar two hours after eating is a finding in its own right.

Sources

2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026 — American Diabetes Association Professional Practice Committee — Diabetes Care, 2026 · Clinical guidelineTwo hours after a 75 g glucose drink, 140 to 199 mg/dL (7.8 to 11.0 mmol/L) is impaired glucose tolerance. Sera applies the same 140 line to a meal, which the guideline does not do. Current edition in force.
Diabetes Tests & Diagnosis — National Institute of Diabetes and Digestive and Kidney Diseases (NIH), 2022 · Government / public-health guidanceTwo hours after the glucose drink, normal is 139 mg/dL or below and prediabetes is 140 to 199. Supports ending the band at 139, not 140.
Continuous Glucose Monitoring Profiles in Healthy Nondiabetic Participants: A Multicenter Prospective Study — Shah VN, DuBose SN, Li Z, et al. — The Journal of Clinical Endocrinology & Metabolism, 2019 · Peer-reviewed publication153 healthy, non-obese US participants aged 7 to 80 wore a blinded glucose sensor: glucose was between 70 and 140 mg/dL for a median 96% of the time and above 140 for 2.1% (about 30 minutes a day). Healthy people seldom exceed 140 at any time, meals included. Says nothing about 120.
Low Blood Sugar (Hypoglycemia) — Centers for Disease Control and Prevention, 2024 · Government / public-health guidanceBlood sugar below 70 mg/dL (3.9 mmol/L) is called low blood sugar, whenever it is measured. The page is written for people with diabetes; it is the conventional figure behind the lower edge of this band.

What Glucose (2h Post-Meal) measures

Blood sugar measured about two hours after eating a normal meal.

Read against the thresholds used for a formal glucose tolerance test, because no separate reference range exists for an ordinary meal. That makes it indicative only: the size and make-up of your meal are unknown, and fat, protein, and fibre all slow how fast sugar arrives in the blood. A light meal can make an impaired response look normal, and a large one can push a healthy person over the line. An HbA1c or a formal tolerance test is what settles the question.

Related blood sugar markers

See 2-hour post-meal glucose in the full list of biomarker ranges

This page is a reference for practitioners, not medical advice. Sera's bands are practitioner targets for structured review, not diagnostic thresholds, and Sera does not diagnose or recommend treatment. Read a result alongside the interval printed by the issuing laboratory and the client's history and symptoms. Range set: Sera Production, version 1.0, last reviewed November 9, 2026.