Do you know what insulin resistance is? How about insulin sensitivity?
Both are terms that are used regularly in the media and by public health professionals, but do you find yourself confused about what insulin health actually is?
Optimal insulin health is a fine balance between the type of food you eat, when you eat it, and how much activity you get. Insulin plays a primary role in managing body composition by mediating fat burning and energy levels, and it is thereby involved in the development of lean mass.
Although insulin health is a complicated process, managing it is probably one of the most important things you can do to feel better and achieve a lean physique.
In this article, the basics of insulin health will be reviewed. It will look at how insulin health influences body composition and energy production, and provide simple strategies for improving it.
What is Insulin?
Insulin is a hormone that is secreted by the pancreas—an organ that sits behind the stomach—primarily after you eat carbohydrates, but also in response to other foods such as whey protein.
When you eat carbs and they are absorbed into the bloodstream, they elevate your blood sugar (also called blood glucose), which the pancreas detects. The pancreas secretes insulin in order to help the body process the blood glucose.
In a healthy body, the insulin binds with receptors on your cells. When a cell has insulin attached to it via the receptor, the cell activates other receptors (that act like messengers) to absorb the glucose from the blood stream into the cell to be used for energy.
What is Insulin Resistance?
Insulin resistance is a continuum; it’s not that you are either insulin resistance or insulin sensitive. These are not absolute terms, and the good news is that you can shift your how your cells respond on the continuum to be more sensitive.
Insulin resistance occurs when your cells are less affected by insulin and the receptors don’t properly bind with the insulin. Insulin resistance is as if you have locks on the door to your cells. In a healthy body, the insulin is similar to a “key” that opens the door of the cell so that the glucose (from carbs you have eaten) can move from your blood into your cells where it is either burned or stored.
If your body is very insulin sensitive and you eat foods that manage insulin secretion, your body will work like a well-oiled machine and the whole process will be very efficient. But, if your cells become resistant to insulin, the pancreas will secrete more and more insulin because of the continued presence of glucose in the blood. The pancreas will think more “keys” are needed to open the door to the cells.
This will lead to high levels of insulin and glucose circulating, but none of either are going where they are supposed to in the body. You will often have low energy levels because your cells are not getting the fuel they need and many other processes in the body will be negatively affected.
What Are the Effects of Insulin Resistance?
There are numerous negative health effects of insulin resistance. In addition to fat gain and higher cortisol, your triglyceride levels will increase, which leads to atherosclerosis and heart disease, and your body will produce free radicals, leading to chronic inflammation and disease.
Insulin resistance will ultimately turn into type 2 diabetes and will affect most, if not all, aspects of health. The primary areas are body composition including belly fat gain, cardiovascular health, and hormone health.
What Is The Difference Between Insulin Resistance And Diabetes?
Remember that insulin resistance occurs on a continuum that is measured most simply with a blood glucose test. The measurement of blood glucose in your blood after an overnight fast will provide an idea of how insulin resistant or sensitive your cells are.
Classifications vary based on the organization providing the guidelines, but a general rule is that normal blood glucose levels run between 70 to 100 mg/dL. Naturally, for optimal health and greater insulin sensitivity, you want to have your blood glucose level lower on this continuum--generally between 75 and 85 mg/dL.
A level between 100 to 125 mg/dL is considered pre-diabetic, and would indicate that the cells are very insulin resistant. A value over 125 mg/dL indicates diabetes.
You can buy a blood glucose test at most pharmacies and perform it at home. Perform the test twice for best results. If you want more information on your insulin health, talk to your doctor about performing an oral glucose test because this will tell you how your body responds when you ingest glucose.
How Do the Fats I Eat Affect Insulin Health?
Even though carbohydrates are the macronutrient that principally raise blood glucose and trigger insulin secretion from the pancreas, the fat you eat plays a primary role in the whole process.
All the cells in the body are made up of two layers of lipids or fats, which will be composed of healthy fats or unhealthy fats, depending on the type you eat. If the cell lipid layers are made up of healthy fats, it will make them more sensitive to insulin and allow the receptors to bind more easily.
Glucose will be able to enter the cell to get burned as fuel. But, if you eat large amounts of trans-fats or have a severe imbalance between the omega-6 and -3 fats in your diet, your cell lipid layers will be made up of those fats. Lipid layers made of unhealthy fats lead to unhealthy cells and greater insulin resistance.
Eat beneficial fats and you will increase insulin sensitivity and cell activity, which can trigger greater fat burning. Beneficial fats include omega-3 fats that are balanced with omega-6 fats. Avoid trans-fats at all costs.
Omega-3 fatty acids are those that commonly come from fish oil (often referred to as DHA, EPA and ALA), but they also can be gotten from grass-fed beef and wild meats. This is why it is suggested the two things you can do for better insulin health and body composition are get adequate omega-3s and eat meats and fish.
How To Balance Omega-3 And Omega-6 Fats
Simply, omega-6 fats are found in vegetable oils (corn, sesame safflower, peanut, etc.) that are used in cooking and producing processed foods. They are found in abundance in the typical Western diet and have resulted in a skewed ratio between omega-6 fats and omega-3 fats.
Human beings evolved on a diet with an equal ratio between these two types of fats because of the high prevalence of wild meat in the diet and complete lack of processed foods. In the typical diet today, that ratio has been skewed to anywhere between 15:1 to as bad as 50:1 of omega-6 fats to omega-3s.The goal is to shift that ratio back to equal for optimal health.
A number of studies have documented this skewed ratio and have found that shifting the intake of omega-6 to more omega-3 fats will result in lower disease rates, particularly cardiovascular disease, cancer, inflammatory and autoimmune disorders, and diabetes.
In relation to insulin health, fats vary in terms of their permeability and omega-3s are the most liquid of the fats. When omega-3s make up a portion of the cell lipid layers, it is easier for the insulin to bind to them because of their liquidity. Omega-6s are next most permeable, followed by other forms of fats, of which trans-fats are the worst—they are sludgy, impermeable fats that do not want to support insulin binding.
What Are Other Simple Tips For Better Insulin Sensitivity?
There are many ways to improve insulin sensitivity, even for people who have blood glucose levels in the normal range. The three main areas to focus on are diet, physical activity, and supplementation.
Tip 1: Eat A High-Protein, Low-Carb Diet
Eating a high-protein, low-carb diet that favors a low-glycemic response has been shown to restore insulin sensitivity in insulin resistant volunteers. Low-carb diets are also useful for fat loss because they reduce hunger and lower calorie intake while improving energy levels.
Tip 2: Manage The Glycemic Response
You’ll have the best insulin health by eating only low-glycemic index carbs such as dark green vegetables and dark colored berries. This will provide carbs with high fiber content, producing a very moderate insulin response.
The best source of fibrous low-glycemic foods are strawberries, blueberries, bilberries, raspberries, cherries, kale, broccoli, lettuce, cabbage, cauliflower, mushrooms, green beans, asparagus, cucumber, spinach, peppers, zucchini. Bananas, pineapples, and oranges have a much higher glycemic index.
Naturally, you may not be ready to eliminate all other carbs from the diet. The solution is to slow digestion and lower the glycemic response by adding foods that support insulin health to high-glycemic foods, such as bread or oatmeal.
If you eat a piece of white or even whole wheat bread, it will be digested very fast and all the carbs will be quickly turned into glucose, raising the overall glucose level rapidly and triggering more insulin to keep up with the high amount of glucose in the blood.
In comparison, low-glycemic bread such as multi-grain bread with added fenugreek (an herb that naturally lowers glycemic index) will be digested more slowly. The carbs will more gradually be turned into glucose, triggering a smaller, more measured insulin response.
Research indicates some of the most effective foods for lowering glycemic response are nuts, fenugreek, cinnamon, strawberries, bilberries, and raspberries.
Tip 3: Limit Fructose In Your Diet
Fructose, which is found in many fruits and in processed foods in the form of high-fructose corn syrup, doesn’t trigger insulin in the way glucose does, but it does mess with insulin health.
In fact, fructose does not stimulate insulin secretion from the pancreas. Rather, it is metabolized by the liver, and if you only eat a very small amount, the liver does this very effectively. But, if the liver is not able to keep up with fructose metabolism, it will be turned into fat and is known to lower glucose uptake (the ability of glucose to get into the cells to be burned) and affect insulin sensitivity.
It’s still unclear why fructose has this effect, but a number of studies have shown that high fructose intake leads to visceral belly fat gain and lowers insulin sensitivity.
It's recommended you limit your intake to 5 to 10 grams of fructose a day, with very active individuals maxing out at 20 grams. Lower fructose fruits and vegetables include most berries, nectarines, grapefruit, avocado, and tomatoes. Bananas, apples, and pears are on the high end of the scale.
Tip 4: Perform A Strength Training Program
There’s no lack of evidence that exercise improves insulin health. In order to exercise or perform even moderate physical activity such as taking a walk or cleaning your house, your body requires energy and as we know, insulin is directly involved in the body’s ability to turn the food you eat into energy.
Both strength training and interval training will improve insulin sensitivity. A higher intensity is better, but even low intensity exercise is beneficial. For best results, heavy weights with a high volume will lead to greater energy use and optimal insulin health.
Tip 5: Do Something Physical Daily and Be More Active
Improve insulin health by being more physically active. We aren’t meant to be a sedentary population, and when we are inactive it affects the body’s sensitivity to insulin.
A recent study looked at how inactivity experienced by individuals with desk jobs affects insulin health. Young healthy individuals who regularly took more than 10,000 steps a day were made to transition to an inactive lifestyle of about 1,500 steps a day for a 14-day period. The inactivity led to much reduced insulin sensitivity and participants gained visceral belly fat.
Make it a goal to take 10,000 steps a day and be sure to perform regular strength training and energy system training. Move as much as possible on days when you are off from scheduled exercise. Doing house work and yard work will support insulin health, as will going up and down stairs and taking brisk walks around the block during the day.
Tip 6: Make Sure Your Basic Nutrients Are Adequate
Aside from omega-3 fish oil, the most important nutrients that support insulin sensitivity are magnesium, zinc, and vitamin D. For best results, get your levels tested.
For zinc, look for a mix of zinc ororate and aspartate. For a magnesium supplement, find one that contains a blend of elemental magnesium—look magnesium ororate, fumarate, glycinate, and taurate because they are most easily absorbed by the body.
For vitamin D, a general suggestion is to take up to 2,000 IUs a day.
Tip 7: Fine Tune Insulin Health With Additional Supplements
There are numerous herbs, minerals, and antioxidants that will improve insulin health by either helping the insulin to bind to the cell, mediate glucose uptake, support energy use, or lower inflammation.
These include probiotics (improve glucose uptake and energy use), vitamin K (improves insulin sensitivity), carnitine (supports fat burning), coffee (lowers inflammation and supports glucose uptake), and green tea (lowers inflammation).