Lifestyle as first‑line therapy
Lifestyle modification is the cornerstone of IR treatment. A 5‑7% weight loss (e.g., 10–15 lb for a 200‑lb person) significantly improves insulin sensitivity.
Nutritional principles
- Carbohydrate quality: choose low‑glycemic index carbs (whole grains, legumes, non‑starchy vegetables, berries). Avoid sugary drinks, white flour, and refined grains.
- Increase fibre: 25–35 g/day from oats, barley, legumes, apples, and vegetables.
- Protein: 1.2–1.6 g/kg body weight, distributed across meals. Lean meats, fish, tofu, legumes.
- Fat quality: replace saturated fats with unsaturated (olive oil, avocados, nuts, fatty fish). Limit trans fats.
- Meal order: vegetables → protein/fat → starches reduces post‑meal glucose spikes.
- Mediterranean diet is the most evidence‑backed pattern.
Physical activity
- ≥150 minutes/week of moderate‑intensity exercise (brisk walking, cycling).
- Strength training 2–3×/week to build muscle mass and raise resting metabolism.
- For women with high cortisol, low‑intensity steady state (LISS) may be more effective than high‑intensity interval training.
Pharmacotherapy when needed
- Metformin – first‑line for T2DM; also used in prediabetes (especially age <60, BMI ≥35, history of gestational diabetes) and PCOS (off‑label).
- GLP‑1 receptor agonists (semaglutide, tirzepatide) – improve IR and promote weight loss.
- Thiazolidinediones – insulin sensitizers, used in select cases.
📌 Metformin indication: not for every case of IR. Specific: T2DM, prediabetes when lifestyle fails (especially high‑risk groups), and PCOS (off‑label). Contraindicated in eGFR < 30 mL/min.