Obesity and Insulin Resistance

Nearly 40% of the U.S. population now suffers from obesity, and 45% suffer from either prediabetes or type 2 diabetes. There is considerable overlap between these diseases, with more than 85% of patients diagnosed with type 2 diabetes also suffering from overweight or obesity. What does that have to do with insulin resistance? Long before type 2 diabetes and even prediabetes is recognized, insulin resistance is already creeping up. Obesity and insulin resistance are interconnected in a variety of ways.

Obesity and Insulin Resistance – What Is Insulin?

Insulin is a hormone that plays a central role in the regulation of blood sugar levels. Insulin determines how the body stores glucose and fat. It helps control blood glucose levels by signaling liver, muscle, and fat cells to take in glucose as fuel from the blood. Insulin is the “gate keeper” unlocking or allowing glucose entry to cells for energy use.

Obesity and Insulin Resistance – What Is Insulin Resistance?

Insulin resistance happens when the body’s cells become resistant to insulin and ever-increasing amounts of it are required to have the same “unlocking” effect on body cells. Insulin resistance is a precursor to prediabetes and type 2 diabetes.

Obesity and Insulin Resistance – Why Does Insulin Resistance Happen?

Insulin resistance can happen due to a combination of genetics and lifestyle leading to an inflammatory process in the body. There are many biological stress factors that can set insulin resistance in motion, including excess nutrition.

When this happens, the body struggles to maintain blood sugar at the correct level. In an effort to keep blood sugar in the normal range, more insulin is secreted from beta cells in the pancreas. A veritable tug-of-war ensues between forces attempting to remove and store sugar in the body’s cells, and those cells themselves that are “full” and becoming less sensitive to the actions of insulin. At some point, tests for fasting blood sugar, postprandial blood sugars (blood sugar checked after a meal) and/or HgbA1c will start to increase. Elevated triglycerides as well as LDL-C (bad cholesterol) may also be seen.

Obesity and Insulin Resistance – How to Treat Insulin Resistance

Insulin resistance is uncommonly identified prior to the onset of prediabetes or type 2 diabetes, as most patients do not have symptoms. However, there are certain signs or risk factors that can alert you to the increased likelihood of insulin resistance, such as increasing waist circumference, weight gain predominantly in the abdominal region, and rising triglycerides and LDL-C (bad cholesterol).

There are a number of ways to improve one’s sensitivity to insulin thereby helping to break the cycle of ever-increasing insulin levels.

• Work on decreasing chronic stress
• Get a good night’s sleep
• Avoid sugar-sweetened beverages and added sugars
• Moderate your processed carbohydrate intake (all carbohydrates are NOT created equal!)
• Move or get NEAT (non-exercise activity time)

Many studies now show that decreasing chronic stress can decrease cortisol hormone levels thereby lowering blood sugar. A good night’s sleep not only leaves you with more energy for NEAT, but also decreases the hunger hormone, ghrelin, so you feel less of an inclination to eat. Movement sensitizes muscle to insulin thereby decreasing insulin resistance. Finally, taking care to limit processed foods lessens blood sugar and insulin spikes that can occur with sugar-sweetened beverages and sugars added to foods.

Frequently Asked Questions

Which foods help with insulin resistance?

Consuming a diet that minimizes insulin stimulation is one of the best ways to help with insulin resistance. Foods that are very high in dietary fiber (like vegetables) and animal proteins (eggs, fish, chicken, etc) have minimal impact on insulin stimulation. Healthy fats like avocado, olive oil, fatty fish, and dairy (in moderation) also have minimal impact on insulin stimulation. Highly processed foods, sugary foods, and simple starches (breads, pasta, tortillas, rice, cereals, crackers, etc) typically stimulate the release of a lot of insulin, worsening insulin resistance.

Are there certain exercises that help with insulin resistance?

Numerous studies have been done trying to answer this question. We know improving a person’s weight in general improves insulin resistance but the question becomes is it better to incorporate aerobic exercise or resistance training. Studies seem to agree that using one or the other type of exercise may be less important than just consistently doing some form of physical activity. Also, either aerobic or resistance training alone can improve insulin resistance but the improvements are greatest when combining aerobic and resistance training.

Can losing weight help with insulin resistance?

In insulin resistance, insulin amounts increase as the muscle is unable to effectively absorb excess glucose (in setting of increased caloric intake); it leads to further insulin production as this excess glucose is converted to extra fat in the liver (via de novo lipogenesis). This increases free fatty acid levels (components of fat) which causes extra fat deposition on the muscles and organs, and allows inflammatory signaling that additionally impairs insulin from effectively pausing liver glucose production after a meal. This leads to a cycle of abnormally increased insulin in the blood, abnormal inflammatory signaling, and increasing excess fat. Therefore, weight (fat) loss, especially of that deposited on the muscles and organs, will trigger a reduction of said abnormal inflammatory signaling and circulating free fatty acids, that would induce a decrease in insulin resistance.

This article was written by Lydia Alexander, MD, FOMA. Dr. Alexander is an obesity medicine physician in Belmont, California.