Everyone should pay attention to metabolic health. When you improve your metabolic health, you set yourself up for a longer, better life.
Metabolic health is synonymous with insulin sensitivity. Being insulin-sensitive helps you regulate blood sugar, burn fat, and reduce your risk of many chronic diseases.[*]
Precisely measuring your insulin sensitivity can be a pain, but that's no excuse to ignore it. Simple diet and lifestyle mods—sleep, exercise, carb restriction, and others—are well-documented to improve insulin function.
Today you'll learn how to increase sensitivity naturally, measure it, and more. First, though, let's define the term.
What Is Insulin Sensitivity?
Insulin sensitivity refers to how efficiently insulin (your blood sugar boss) stores blood sugar in cells. When you're insulin sensitive, your liver and muscle cells suck up blood glucose like a vacuum, and your blood sugar stays within healthy ranges.
The obverse of insulin sensitivity is insulin resistance. Since insulin-resistant muscle and liver cells don't listen to insulin, blood sugar stays too high for too long.[*] Much of that blood sugar is later stored as fat.
Insulin resistance is the central pathology of type 2 diabetes. It shows the consequences of poor insulin sensitivity—high blood sugar, runaway fat storage, and a hyper-inflated risk for every chronic disease.
Measuring Insulin Sensitivity
There are several ways to measure insulin sensitivity, some easier than others. The most scientifically validated method entails clamping the liver (to stabilize glucose production) while insulin is dripped into the patient to assess the glucose response.[*] This and other IV-based techniques are as convenient as flying cross-country with two layovers and a carry-on bag that needed to be checked (lost) by the airline staff.
You can also measure insulin sensitivity with an oral glucose tolerance test (OGTT). This procedure entails drinking a bunch of glucose and hanging around for 2–4 hours as test takers sample your blood regularly. It's not a fun way to spend your Friday, but probably worth it if you're concerned about diabetes.
More convenient yet less precise markers of insulin sensitivity include:
- Fasting insulin. Not sufficient for diabetes diagnosis, but lower values (under 12.2 mu/mL) correlate with insulin sensitivity.[*]
- The glucose to insulin ratio. A fasting glucose to fasting insulin ratio under 4.5 predicted insulin resistance in 40 women with PCOS.[*]
- Homeostatic model assessment (HOMA). If the product of fasting insulin and fasting glucose divided by 405 is greater than 4.5, the patient is considered insulin-resistant.[*]
Another crucial metric for people with diabetes—the insulin sensitivity factor—measures how much blood sugar drops per each unit of insulin administered. (A factor of 1:60 means blood sugar goes down 60 mg/dL per insulin unit.) To calculate your insulin sensitivity factor, you divide a constant (1800 for regular insulin and 1500 for rapid-acting insulin) by the number of insulin units you take daily.
The Benefits of Improving Insulin Sensitivity
For a better health span and lifespan, aim to avoid insulin resistance. The benefits of boosting insulin sensitivity include:
- Spending less time with elevated blood sugar (hyperglycemia), an inflammatory state that damages blood vessels and deactivates DNA repair genes
- Returning more rapidly to fat burning after consuming carbs
- More stable energy and lower cravings thanks to fewer blood sugar excursions
- Lower risk of heart disease, neurogenerative disease, liver disease, diabetes, and many cancers[*][*]
- Requiring less supplemental insulin (for folks with diabetes)
- All the benefits that come with living a healthy lifestyle
The last bullet seems obvious, but it's a critical insight. When you enhance your insulin sensitivity by exercising, sleeping better, and eating right, those behaviors ricochet into every area of your well-being.
5 Ways to Increase Insulin Sensitivity Naturally
Speaking of improving your health, let's move to tactics. How should you design your life to optimize for insulin sensitivity?
Quick caveat: we won't discuss drugs (like Metformin) or supplements (like berberine) that may improve insulin sensitivity. Do your homework on these molecules, but understand that no pill can substitute for exercise, sleep, and proper nutrition.
Exercise may be your sharpest tool for improving insulin sensitivity. Regular aerobic exercise enhances metabolic health while lowering the risk for nearly every chronic disease.[*]
And it's not just cardio. Strength and high-intensity interval training (HIIT) also give you a nice bump in insulin function. For example, six weeks of HIIT training (3 cycling sessions per week) improved insulin sensitivity while reducing LDL cholesterol and fat mass in older adults.[*]
#2: Don't Overeat (Especially Carbs)
You set yourself up for metabolic dysfunction when you consume more calories than your metabolism burns. Even healthy foods (almonds, anyone?) can be overdone.
But it's easier to overdo refined carbs than protein-rich whole foods. It's easier to binge on hyper-palatable cookies than salmon with broccoli.
That's why whole foods approaches like Keto and Paleo tend to work for weight loss and blood sugar regulation.[*] Keto is an effective insulin sensitivity diet because it keeps you satiated—plus it limits the macronutrient (carbs) that elevates blood sugar the most.
#3: Consider time-restricted feeding
Another way to limit portions is to limit your feeding window. When you compress your feeding to the window of 8–12 hours, you're less likely to overeat.
#4: Sleep well
Did you know a good night's sleep enhances your fat-burning capacity the next day? When you sleep well, you need less insulin to manage your blood sugar.[*] When you need less insulin, you burn more fat.
#5: Manage stress
Chronic stress brings a boatload of consequences. Here are some linked to insulin resistance:[*]
- Stress eating
- Impaired beta cell function (beta cells in the pancreas help manage glucose levels)
- Elevated LDL cholesterol
- Increased inflammation
- Overstimulation of the autonomic nervous system
- Higher cortisol levels
- Issues with fluid balance
You'll never be 100% stress-free—nor should you try to be—but meditation, yoga, sleeping well, and avoiding work overload can help keep chronic stress in check.
Staying Insulin Sensitive
The more insulin-sensitive you are, the more metabolically healthy you'll be. And metabolic health is a foundation of longevity.
Stay insulin sensitive by:
- Keeping portions in check (especially carbs)
- Getting enough sleep
- Eating within a compressed window
- Paying attention to stress management
Pick one of these areas and make a slight improvement today. Repeat this process enough times, and you'll give your future self the gift of better health.