Keto Diet and Blood Sugar: How Ketosis Impacts Your Glucose Levels

Controlling blood sugar levels is critical for people with diabetes. It can also help those without diabetes reduce their risk for developing it. But is the popular high-fat, low-carb ketogenic (keto) diet an effective approach for blood sugar management? This extensively researched article provides insights into how ketosis from the keto diet affects glucose control.


The ketogenic diet has surged in popularity over the past decade, hailed for its ability to boost fat loss, curb appetite, and improve markers of metabolic health. But one of the lesser known benefits of keto is its potential to stabilize erratic blood sugar levels in individuals with insulin resistance or type 1 and type 2 diabetes.

By dramatically reducing carbohydrate intake and replacing it with healthy fats, the keto diet can help regulate blood glucose by inducing a metabolic state known as ketosis. Read on to understand exactly how ketosis works, what impact it has on blood sugar, and the precautions to take if using keto for better glucose control.

1: Understanding the Ketogenic Diet

The ketogenic or “keto” diet is centered around achieving and maintaining ketosis through very low carbohydrate consumption, moderate protein intake, and high amounts of fat.

Ketosis occurs when liver glycogen stores are depleted and the body must rely almost solely on fat for fuel in the absence of dietary carbohydrates. The liver ramps up production of ketones like β-hydroxybutyrate and acetoacetate, which can cross the blood-brain barrier and provide an alternative energy source for the brain and body.

This contrasts with the normal physiological state where blood glucose from carbs constitutes the main source of energy. Switching the body’s primary fuel source from carbs to ketones via the keto diet positively impacts biomarkers associated with blood sugar regulation.

2: The Impact of Keto on Blood Sugar

Restricting carbohydrate intake to just 5-10% of total calories leads to a number of adaptations that can stabilize erratic blood sugar levels.

First, eliminating carbs naturally reduces and prevents substantial blood sugar spikes. With less glucose entering the bloodstream, insulin needs are lowered.

Secondly, ketone production ramps up in the liver, which prioritizes metabolizing fatty acids and manufacturing ketones over storing excess glucose as glycogen. This blood glucose-lowering effect allows ketones to step in as the body’s predominant fuel source.

Ketones themselves appear to have an insulin regulating effect by reducing hepatic gluconeogenesis, which is the formation of glucose in the liver.

Finally, burning fatty acids and tapping into ketones prevents energy level crashes and spikes associated with fluctuating blood sugar. The keto diet provides steady fuel.

3: Blood Sugar Management With Keto

Due to its glucose and insulin stabilizing effects, the keto diet can be an effective tool for managing blood sugar disorders like type 2 diabetes and prediabetes.

Studies demonstrate keto lowers fasting blood glucose levels, HbA1c, and postprandial glucose in individuals with type 2 diabetes. Insulin resistance improves as well.

Experts theorize ketosis may also benefit people with type 1 diabetes by reducing glycemic variability. However, close medical monitoring is required as hypoglycemia is a risk.

The diet’s ability to rein in blood sugar likely stems from the switch to ketones for fuel, which prevents energy level and blood sugar fluctuations. Keto improves insulin sensitivity and counters dysfunction in glucose metabolism.

4: Potential Concerns

Despite its utility for glycemic regulation, there are some cautions related to starting a ketogenic diet:

  • Blood sugar can drop too low in diabetics if medications are not adjusted or if consuming very low carb. Monitoring is critical.
  • The diet is extremely restrictive in carbs, making compliance and sustainability difficult for some individuals long-term.
  • Transitioning into ketosis can provoke temporary glucose fluctuations and unpleasant symptoms dubbed “keto flu.”

Working with a knowledgeable physician reduces potential risks and increases the odds of success on a well-formulated keto diet.

5: Keto-Friendly Foods

To control blood sugar effectively on keto, focus on very low carb, high fat whole foods like:

  • Non-starchy vegetables – leafy greens, zucchini, broccoli, onions, asparagus
  • Avocados and berries
  • Grass-fed meats, poultry and wild-caught fish
  • Eggs
  • Full-fat dairy – hard cheeses, plain Greek yogurt
  • Nuts and seeds
  • Healthy oils – olive, avocado, coconut

A sample keto meal plan might include a spinach, mushroom, and feta omelet; salmon over zucchini noodles with pesto; chicken thighs with broccoli; taco salad with ground beef.

6: Tips for Beginners

Those new to the keto diet should adhere to the following recommendations to ensure safe and effective blood sugar management:

  • Consult your physician or a certified diabetes educator before starting. Medication adjustments are often required.
  • Transition slowly into ketosis over 2-3 weeks. Drastic carb restriction can provoke low blood sugar.
  • Monitor glucose closely when first starting out. Know the signs of hyperglycemia and hypoglycemia.
  • Stay well hydrated and replenish electrolytes like sodium, potassium and magnesium to minimize side effects.

7: Keto Diet Success Stories

Many individuals have experienced impressive improvements in their blood sugar control following a well-formulated ketogenic diet. Here are some inspirational examples:

Brian (46): By sticking to under 30g of carbs daily Brian reduced his HbA1c from 9.2% to 5.5% and no longer needs diabetes medication.

Amy (28): Amy struggled with hypoglycemic episodes for years until starting keto. Her glucose levels finally stabilized.

James (54): James lost 50 lbs, reversed his type 2 diabetes, and got his A1c down to 5.2% in just over 3 months doing keto.

8: Overcoming Challenges

The largest hurdle when transitioning to keto is overcoming “carb flu” symptoms in the first few weeks as your body adapts to using ketones and fatty acids for fuel instead of glucose. Other challenges include:

  • Dealing with cravings for carbohydrates and sugar
  • Fatigue, GI issues, headaches, poor focus
  • Social situations like dining out where you have limited options
  • Meal planning and determining appropriate macros

Planning keto-friendly meals ahead of time, tracking your macros, adding more salt, magnesium and potassium, staying active, drinking plenty of water, and using supplements like MCT oil can help overcome many of the initial challenges.


Research suggests that a well-formulated ketogenic diet can be a viable option for improving erratic blood sugar levels by inducing ketosis. However, medical support is strongly recommended, especially for individuals with diabetes who are looking to reduce dependence on medication.

While keto poses some challenges initially, it can be a sustainable lifestyle change resulting in better glucose control for many people. As with any major diet change, consult your doctor first and use caution.

About the Author

Nicole Carter is a dedicated and passionate nutritionist, committed to helping individuals achieve their health and wellness goals through the power of proper nutrition. With a Bachelor's degree in Nutritional Science and years of practical experience.

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