Intermittent fasting and insulin resistance: why results can stall
Intermittent fasting (IF) is a popular approach for boosting metabolic health and promoting weight loss. But for individuals with insulin resistance, IF doesn’t always deliver the expected payoff. Wellness expert and best-selling author Dr. Eric Berg notes that insulin resistance can blunt IF by hindering the body’s shift into fat-burning mode. Understanding the obstacles is the first step to turning IF into a reliable tool for weight management.
Five common mistakes that undermine intermittent fasting
1) Consuming too many carbohydrates
Carbs are not the enemy in every context, but high daily carbohydrate intake can keep insulin elevated and prevent fat from being released as fuel. Even during eating windows, frequent carbohydrate-rich meals can maintain a higher insulin level, making it harder for the body to switch into fat-burning mode. To improve insulin sensitivity, many experts—including Dr. Berg—advise moderating carb intake and favoring foods that have a gentler impact on blood sugar.
2) Short fasting periods
Short fasts may not reduce insulin sufficiently to unlock fat breakdown. Dr. Berg recommends longer fasting windows, such as an 18-hour fast, to more effectively lower insulin levels and encourage the body to tap into stored fat for energy. Extending the fast can help reset the metabolic clock and support weight loss and better metabolic function over time.
3) An insufficiently nutrient-dense eating pattern
IF is as much about what you eat as when you eat. Merely skipping meals without choosing nutrient-rich foods can blunt the benefits of fasting. Dr. Berg highlights a diet that’s low in carbohydrates but high in healthy fats and moderate in protein. This approach can help improve insulin sensitivity and provide steady energy during eating periods, supporting overall metabolic health.
4) Chronic stress and cortisol surges
Stress triggers cortisol release, which can raise blood sugar and insulin, worsening insulin resistance. Prolonged stress can undermine IF by keeping the body in a sympathetic state. Practical strategies—such as regular sleep, mindfulness or relaxation techniques, and consistent physical activity—can help regulate cortisol and boost insulin sensitivity.
5) Preexisting health conditions
Certain health issues, including fatty liver, can disrupt liver function and complicate glucose metabolism. Dr. Berg emphasizes addressing root health problems alongside IF. Treating underlying conditions can restore insulin sensitivity and enhance the effectiveness of fasting-based weight management.
How to maximize intermittent fasting if you have insulin resistance
To improve the odds of success with IF when insulin resistance is a factor, consider these evidence-informed adjustments:
- <strongAdopt a low-carb, high-fat diet: Reducing carbohydrate intake while increasing healthy fats can improve insulin sensitivity and support steady energy during fasting.
- <strongExtend fasting to 18 hours: Longer fasting windows can more effectively lower insulin and promote fat burning.
- <strongPrioritize stress management: Sleep optimization, mindfulness practices, and regular physical activity help regulate cortisol and insulin response.
- <strongTreat underlying conditions: Address liver health and other metabolic issues to restore glucose processing and insulin sensitivity.
- <strongMonitor nutrients: Ensure adequate intake of micronutrients and fiber to support metabolism and satiety during eating windows.
Implementing these measures thoughtfully can help someone with insulin resistance get better results from intermittent fasting and improve overall well-being.
Final takeaway
Intermittent fasting remains a powerful tool, but its success hinges on more than the timing of meals. By reducing refined carbohydrate intake, extending fasting periods, managing stress, and treating underlying health issues, individuals with insulin resistance can unlock the fat-burning potential of IF and enjoy more consistent weight-loss progress.
