Should my blood sugar and insulin levels be checked after eating?

From the Guidelines

Given your symptoms of falling asleep easily after eating, it is crucial to assess your blood sugar and insulin levels after meals to rule out conditions like reactive hypoglycemia or insulin resistance, as recommended by the most recent guidelines 1. This approach is supported by the latest standards of care in diabetes, which emphasize the importance of individualized glycemic goals and monitoring strategies 1. The guidelines suggest that postprandial glucose measurements should be made 1–2 hours after the beginning of the meal, generally when peak levels occur in patients with diabetes 1. Key points to consider include:

• Your fasting insulin levels have been slightly elevated, at 11 in 2021 and 12 in 2022, which may indicate some level of insulin resistance or impaired insulin sensitivity.
• Your normal A1C and blood glucose levels do not necessarily rule out the possibility of postprandial dysglycemia, which can have significant implications for your health and quality of life.
• The recent guidelines from 2025 provide updated recommendations on pharmacologic approaches to glycemic treatment, including the adjustment of insulin doses based on postprandial glucose levels 1.
• It is essential to discuss your specific situation and symptoms with your healthcare provider, who can recommend the most appropriate testing schedule and treatment plan based on your individual needs and health status. Considering the potential risks and benefits, it is reasonable to recommend postprandial testing to assess your glycemic control and insulin response after meals, as this can provide valuable insights into your metabolic health and guide personalized interventions 1.

From the FDA Drug Label

During treatment initiation and dose titration (see below), one-hour postprandial plasma glucose may be used to determine the therapeutic response to acarbose tablets and identify the minimum effective dose for the patient.

Given your symptoms of falling asleep easily after eating, it may be beneficial to check your blood sugar and insulin levels after eating to determine if you are experiencing any postprandial glucose spikes. This is because your fasting insulin levels have been relatively stable, and your A1C and blood glucose levels have been normal, but you are still experiencing symptoms that could be related to blood sugar fluctuations. Checking your postprandial glucose levels can help identify if there is an issue with your body's ability to regulate blood sugar after meals. 2

From the Research

Postprandial Blood Sugar and Insulin Levels

• Your fasting insulin levels were 11 in 2021 and 12 in 2022, with normal A1C and blood glucose levels, but you experience easy sleepiness after eating, which may indicate postprandial hypoglycemia or reactive hypoglycemia 3.
• Postprandial reactive hypoglycemia is a condition where blood glucose levels drop 2-5 hours after eating, and it can be caused by excessive insulin secretion after a meal 3.
• Studies suggest that postprandial blood glucose and insulin excursions can be improved with exercise, and the timing of exercise around meals can modify the effects of exercise on glycemic control and insulin sensitivity 4.

Importance of Checking Blood Sugar and Insulin Levels After Eating

• Checking blood sugar and insulin levels after eating can help diagnose postprandial hypoglycemia or reactive hypoglycemia, especially if you experience symptoms such as sleepiness after eating 3, 5.
• Targeting postprandial glucose control can improve overall glycemic control and long-term prognosis in patients with type 2 diabetes, and it may also be beneficial for individuals with normal glucose tolerance but who experience postprandial hypoglycemia 6.
• The liver plays a critical role in postprandial glucose homeostasis, and its ability to dispose of ingested glucose can help regulate postprandial glucose fluctuations 7.

Potential Benefits of Monitoring Postprandial Blood Sugar and Insulin Levels

• Monitoring postprandial blood sugar and insulin levels can help identify individuals who may be at risk of developing type 2 diabetes or who may have underlying insulin resistance 3, 4.
• It can also help healthcare providers develop personalized treatment plans to improve glycemic control and reduce the risk of complications associated with postprandial hypoglycemia or reactive hypoglycemia 6, 5.