Fasting level after eating a lots of sweets

by Sadegh
(San diego)

Original Question

My fasting sugar was 112 mg/dL after a night of eating a lot of cakes and rice. Could the food I ate the night before explain the higher fasting result?

Quick Answer:

A fasting glucose of 112 mg/dL (6.2 mmol/L) is above the normal laboratory fasting range and falls within the 100–125 mg/dL prediabetes range. One reading does not diagnose prediabetes, and a heavy meal the night before may influence glucose, but the result should not automatically be blamed only on the cakes and rice.

Answered by:
Dr. Albana Greca, MD, MMedSc

Family Physician, IDF Fellow

Is a Fasting Blood Sugar of 112 High?

Yes, it is mildly elevated. For a laboratory fasting plasma glucose test, below 100 mg/dL is considered normal, while 100–125 mg/dL is in the prediabetes range. Diabetes is diagnosed at 126 mg/dL or higher when confirmed appropriately.

If you want to compare your number with the usual fasting ranges, our guide to
normal fasting blood sugar levels
explains how borderline results are interpreted.

Can Eating Sweets the Night Before Raise Fasting Glucose?

A very large evening meal, especially one rich in refined carbohydrates such as cakes and large portions of rice, can affect overnight glucose in some people. Sleep, stress, illness, alcohol and certain medicines can also influence a fasting result.

However, if you truly fasted for at least eight hours, a value of 112 mg/dL should not simply be dismissed because of what you ate the night before. It is more useful to look for a pattern.

What Should You Do Next?

Repeat the fasting glucose on another morning under normal conditions.

Fast for at least 8 hours, allowing only water unless your clinician says otherwise.

If home readings remain elevated, ask your clinician for a laboratory fasting plasma glucose.

Consider an HbA1c test, especially if fasting results repeatedly stay above normal.

The different blood tests used for diabetes and prediabetes are not interchangeable, so proper laboratory testing is important before drawing conclusions.

If You Already Have Diabetes

If you already have diabetes, a fasting reading of 112 mg/dL may fall within the treatment target used for many adults, although personal goals vary. The important question is whether your fasting and post-meal readings are consistently within the targets set with your healthcare professional.

Looking at your readings across the day can be more useful than focusing on one number, which is why our
blood sugar levels by time of day
guide may help.

Important:

Do not diagnose yourself with prediabetes from one home glucose-meter reading. Diagnosis should be based on properly performed laboratory testing.

My Practical Advice

Return to your usual eating pattern, avoid unusually large late-night meals, sleep normally if possible and repeat the fasting test. If fasting values continue to be 100 mg/dL or higher, discuss a laboratory fasting glucose and HbA1c with your healthcare professional.