Knowing healthy postprandial glucose values is a worthwhile target to get healthier. A Cleveland Clinic expert shares the sweet spot and tips to keep your blood sugar steady.
Blood Sugar After Eating—What Are Good Numbers? A Clinical Expert Speaks
Published on Jan. 06, 2025
One of your health goals might be to cut back on sugar, and that’s a wise one. Understanding your blood sugar levels after eating is a key part of maintaining overall health.
Whether you’re managing diabetes, at risk, or simply striving for healthier habits, knowing how food affects your blood sugar can help you avoid potential health complications.
When you eat, carbohydrates break down into glucose, which enters your bloodstream and raises your blood sugar. While some people’s levels return to normal quickly, others may experience prolonged elevations.
To properly manage your blood sugar, it’s important to understand what’s considered normal and how to respond when levels are too high. Ahead, Gillian Culbertson, MS, RD, LD, CSOWM, a registered dietitian who works with adult diabetic patients with the Cleveland Clinic Center for Human Nutrition, explains what your post-meal blood sugar levels should be, how to address elevated levels, and when it’s time to consult your doctor.
What are normal blood sugar levels?
Blood sugar levels, measured in milligrams per deciliter (mg/dL), can vary based on factors such as age, overall health, and medical conditions. Culbertson outlines the general fasting (before eating) blood sugar targets for different groups:
- Adults without diabetes: 70-99 mg/dL
- Adults with diabetes: Under 120 mg/dL
- Pregnant individuals: Less than 95 mg/dL
- Children and adolescents ages 6-12: 80-180 mg/dL
- Adolescents ages 12-19: 70-150 mg/dL
Children and teens often have slightly higher blood sugar targets to reduce the risk of hypoglycemia, or dangerously low blood sugar, which can impact brain development. Factors like growth spurts, hormonal shifts, and increased sensitivity to glucose changes make this age group particularly susceptible to blood sugar drops. To maintain their health and safety, regular monitoring and personalized guidance from healthcare providers are smart practices.
What should your blood sugar levels be after eating?
After eating, it’s normal for blood sugar levels to rise as your body breaks down food into glucose for energy. Keeping these levels within a healthy range is important, not just for managing diabetes but for overall health.
Here are general post-meal blood sugar guidelines, as dietitan Culbertson shares:
- Adults without diabetes: Below 140 mg/dL within 1-2 hours after eating.
- Adults with diabetes: Less than 180 mg/dL within 1-2 hours. However, as Culbertson explains, goals can vary depending on the healthcare provider, institution, and the patient’s unique medical conditions. For some, a target of under 160 mg/dL may be more appropriate.
- Pregnant individuals: Blood sugar should stay below 140 mg/dL at 1 hour and below 120 mg/dL at 2 hours post-meal to reduce risks for both parent and baby.
- Children and adolescents: Post-meal levels are generally recommended to be less than 140 mg/dL, though exact targets depend on age and other health factors.
How to check your blood sugar levels
“A1c is the primary tool to assess glycemic control,” Culbertson says. Hemoglobin A1c, or glycated hemoglobin, is a blood test that measures your average blood sugar levels over the past two to three months. This test helps indicate how well your blood sugar is being managed. The general recommendation is to check A1c initially and then routinely during care, typically every three months. For those with stable control, testing twice per year is often sufficient.
Here are the reference ranges for A1c:
- Normal: Less than 5.7%
- Adults with diabetes: Less than 7%
- Children with diabetes: Goals vary, usually ranging from 6.5% to 8%
In addition to A1c, blood sugar levels can be monitored through fingerstick blood glucose tests or continuous glucose monitoring (CGM) devices. “Glucose monitoring can provide valuable feedback on how blood sugar responds to meals, physical activity, and medication changes,” Culbertson notes. “[Measuring] at different times of the day is best to provide a good overview of what glucose is doing.”
Fasting blood sugar is performed in the morning after an eight- to 10-hour fast. Pre-meal blood sugar is checked just before eating, and postprandial blood sugar is measured two hours after the first bite of a meal.
For pregnant women, monitoring often includes a fasting blood sugar test and a post-meal test one hour after eating.
The frequency of testing depends on the type of diabetes you have, your treatment plan, and your overall health. Your healthcare provider will guide you on how often to check. You might need to test more frequently if you are sick, traveling long distances, or making changes to your diet or exercise routine.
It’s also important to keep a detailed record of your readings, as it helps you and your healthcare provider monitor patterns, evaluate the effectiveness of your treatment, and make informed decisions about your care.
Here’s how to check your blood sugar using the following devices:
Fingerstick blood glucose tests
- Begin by thoroughly washing and drying your hands to remove any substances that could affect the reading.
- Insert a test strip into the blood sugar meter, then use the lancet (a small needle typically provided with your test kit) to gently prick the side of your fingertip. Touch the edge of the test strip to the drop of blood, and within seconds, your blood sugar level will appear on the meter’s screen.
- To ensure accurate results, always follow the instructions that come with your meter.
Note some “smart” fingerprick products synch with an app that’s downloadable to a smartphone. One advantage to these is that the app tracks your blood glucose over time so that you can easily monitor for problems or trends. While there are reasonably priced high-tech options available, some individuals may be just as content using an analog version.
Continuous glucose monitors (CGMs)
Continuous glucose monitoring devices measure glucose levels continuously throughout the day, offering a comprehensive view of fluctuations. These devices consist of a sensor placed under the skin, which sends real-time glucose readings to a monitor or smartphone.
CGMs are beneficial for individuals with type 1 diabetes and some with type 2 diabetes, as they provide insights into glucose trends for daily management and long-term care adjustments.
In 2024, the first continuous glucose monitor for nondiabetics was introduced to the market, with more brands beginning to launch.
What to do if you have high blood sugar after eating
Culbertson advises: “First, problem-solve to try to determine why it is high.” Elevated blood sugar levels can result from various factors, including stress, illness, or pain; missed medication; consuming more food than usual; or issues with insulin, such as expired or improperly stored insulin, incorrect dosing, or administration errors.
Next, recheck your blood sugar level to confirm accuracy. “Make sure to wash and dry your hands properly before a finger stick and ensure your meter is working correctly,” Culbertson notes. “It’s [also] important to stay well hydrated with water or calorie-free beverages.” This can help “flush” the sugar from your system. Aim for eight to 10 cups of fluids daily unless otherwise advised by your doctor.
If your blood sugar remains elevated, or if over 240 mg/dL, call your doctor. This can strongly increase the risk of a medical event such as a stroke.
5 tips for managing blood sugar levels after eating
Seek professional guidance
“See a dietitian for a diet that is appropriate for your medical needs, lifestyle, and preferences,” Culbertson says. A personalized plan should include recommendations for maintaining a healthy body weight, managing energy needs, and balancing carbohydrates, lean proteins, and healthy fats. It may also address other medical conditions if necessary.
Balance your plate
“Carbohydrates are an important, healthy part of a diet,” Culbertson says, adding that the diabetes plate method is an effective guide for portion control. This involves filling half your plate with non-starchy vegetables, a quarter with lean protein, and the remaining quarter with whole-grain starches.
Stick to a regular eating schedule
During the day, “Try to avoid going longer than four to five hours between meals, and include healthy snacks with protein and fiber if needed,” Culbertson suggests. Eating until you feel just satisfied, not overly full, can also help maintain blood sugar stability.
Incorporate regular physical activity
Engage in 30 to 40 minutes of cardio most days, and add resistance training two to three times per week to help manage blood sugar levels.
Prioritize rest and stress management
Aim for seven to nine hours of quality sleep each night, and adopt effective stress-management techniques to support overall blood sugar control.
High blood sugar symptoms
Recognizing the signs of elevated blood sugar levels is important for taking timely action and seeking help. Common symptoms include:
- Frequent urination
- Excessive thirst
- Fatigue
- Blurred vision
- Headaches
- Slow wound healing
If high blood sugar persists, long-term symptoms may develop, such as:
- Nerve damage (neuropathy)
- Kidney disease
- Cardiovascular issues
High blood sugar causes
Understanding the causes of high blood sugar can help with prevention and management. Some causes include:
- Overeating or consuming high-carbohydrate meals
- Stress or illness
- Lack of physical activity
- Missing medication doses
- Hormonal changes, such as during pregnancy
Key risk factors to watch for are:
- Family history of diabetes
- Obesity
- Sedentary lifestyle
- Poor diet
- Age (risk increases as you get older)
Dangers of having high blood sugar
Unchecked high blood sugar levels can have serious consequences, including:
- Type 2 diabetes
- Heart disease
- Stroke
- Vision loss (retinopathy)
- Kidney failure
- Nerve damage
How to treat high blood sugar
Managing high blood sugar involves both immediate actions and long-term habits. If your blood sugar is elevated, consider the following steps:
- Exercise regularly to help lower glucose levels naturally.
- Stay hydrated by drinking plenty of water.
- Stick to your meal plan and avoid high-sugar foods.
- Take prescribed medications, such as insulin or oral diabetes drugs, as directed by your healthcare provider.
- Monitor your blood sugar frequently to catch and manage spikes early.
When to talk to your doctor
Regular checkups and blood tests can help detect and manage blood sugar problems early. See your doctor if your blood sugar stays high consistently after eating, you experience symptoms listed above like blurred vision, fatigue, or headaches and your blood sugar readings exceed 240 mg/dL.
About the expert
Gillian Culbertson, MS, RD, LD, CSOWM, is a clinical registered dietitian with the Cleveland Clinic Center for Human Nutrition, where she has been providing care since 2007. Based in Wooster, OH, she earned her Master of Science in Medical Dietetics from The Ohio State University, and is also a certified specialist in obesity and weight management.
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