How to improve insulin resistance?

How to Improve Insulin Resistance

Insulin resistance requires a structured combination of at least 150 minutes weekly of moderate-intensity aerobic exercise, 2-3 sessions of resistance training, and achieving 5-7% weight loss through caloric restriction—diet alone is insufficient. 1

Exercise: The Primary Intervention

Aerobic Activity Requirements

• Perform at least 150 minutes per week of moderate-intensity aerobic exercise, distributed over at least 3 days with no more than 2 consecutive days without activity. 2, 1
• Each aerobic session should last at least 10 minutes, progressing toward 30 minutes per day most days of the week. 2
• Daily exercise is optimal because insulin sensitivity improvements last only 2-72 hours after each session. 2
• Even one week of aerobic training can improve whole-body insulin sensitivity. 2

Resistance Training Requirements

• Include 2-3 sessions per week of resistance exercise on non-consecutive days, involving major muscle groups. 2, 1
• Progressive resistance training for 16 weeks can increase insulin action by 46.3% and reduce fasting glucose by 7.1%. 2
• Each session should consist of at least one set of five or more different resistance exercises. 2
• Heavy resistance training may reverse loss of skeletal muscle mass and improve glucose uptake through increased muscle mass. 2

Reducing Sedentary Time

• Break up prolonged sedentary periods (≥30 minutes) by briefly standing, walking, or performing light physical activities. 2, 1
• Avoiding extended sedentary time helps prevent type 2 diabetes and aids glycemic control. 2

Weight Loss: Essential Component

Target and Timeline

• Achieve 5-7% weight loss from initial body weight. 2, 1, 3
• Create a caloric deficit of 500-1,000 calories per day from maintenance needs. 2, 1
• Aim for 1-2 pounds per week initially. 1
• Structured programs with frequent participant contact are necessary—standard weight reduction diets alone produce poor long-term outcomes. 2

Evidence of Effectiveness

• The Diabetes Prevention Program demonstrated that intensive lifestyle intervention (achieving 5-7% weight loss plus 30 minutes daily moderate activity) reduced diabetes risk by 58% over 3 years. 1
• This was twice as effective as metformin (58% vs 31% risk reduction). 1
• The Finnish Diabetes Prevention Study showed similar 58% risk reduction with ≥5% weight loss combined with dietary changes and >4 hours weekly exercise. 1

Dietary Modifications

Carbohydrate Quality (Not Quantity)

• Prioritize low glycemic index carbohydrates: non-starchy vegetables, whole fruits (not juices), legumes, and whole grains. 2, 3
• Consume 14g of fiber per 1,000 kcal of total intake. 2, 3
• High fiber intake, especially cereal fiber, decreases risk of type 2 diabetes and cardiovascular disease. 2
• Eliminate sugar-sweetened beverages and minimize foods with added sugars. 2, 3

Fat Composition

• Limit saturated fat to <7% of total calories. 3
• Reduce total fat to <30% of daily energy intake. 2, 1
• Minimize trans fats completely. 3
• Emphasize Mediterranean-style diet rich in monounsaturated and polyunsaturated fats. 3

Dietary Pattern

• Follow a diet rich in fruits, vegetables, whole grains, lean proteins, and low-fat dairy products. 1
• The Mediterranean diet improves glucose metabolism and reduces insulin resistance. 3
• Restricting fat is probably the most important nutrient to restrict when dieting for weight loss, as spontaneous food consumption increases with high-fat diets. 2

Critical Implementation Points

Why Diet Alone Fails

• Intensive lifestyle changes are necessary—current dietary recommendations alone, even when vigorously implemented, do not significantly improve insulin sensitivity. 1, 4
• Improved aerobic fitness appears to be the major difference between successful and unsuccessful interventions. 4
• Without structured exercise and weight loss components, long-term outcomes are poor and most people regain lost weight. 2

Monitoring and Adjustments

• Insulin sensitivity improvements from exercise last only 2-72 hours, necessitating regular ongoing activity rather than sporadic efforts. 2
• For patients taking insulin or insulin secretagogues, monitor for hypoglycemia during exercise and may need to ingest added carbohydrate if pre-exercise glucose <100 mg/dL. 2, 1

Common Pitfalls to Avoid

• Do not rely on supplements—there is insufficient evidence for chromium, vitamin D, cinnamon, or other herbals/micronutrients to improve glycemic control. 2
• Do not recommend antioxidant supplements (vitamins E, C, carotene) due to lack of efficacy and safety concerns. 3
• Very low calorie diets produce rapid improvements but weight regain is common when stopped, limiting their utility. 2

Alcohol Considerations

• If consuming alcohol, limit to 1 drink/day for women and 2 drinks/day for men. 3
• Moderate alcohol intake does not have major detrimental effects on long-term glucose control. 2