Is insulin sensitivity and insulin resistance the same thing?

Blood sugar levels typically stay within a narrow range, even after a meal and are in part regulated by the hormone insulin. Some people have high insulin sensitivity, needing little insulin production, while those with insulin resistance require much more.

Understanding insulin resistance

Genetic factors play a big role, but other influences exist as well. There is variability in insulin resistance at any level of body fat as not all fat causes insulin resistance; in fact, storing fat in small cells under the skin (subcutaneous fat) can help protect against it.

Insulin resistance often develops when our personal fat threshold is exceeded. When this happens, the fat tissue under the skin (subcutaneous fat) can’t grow by making new cells and instead grows existing ones; it also leads to more fat stored in inner organs (called ectopic) and around organs, muscles, liver, and pancreas, known as visceral fat.  These big fat cells can become dysfunctional, and the increased body fat mass can lead to many inflammatory substances, causing chronic low-grade inflammation, which is linked to insulin resistance, metabolic syndrome, and higher risk of chronic diseases like type 2 diabetes, heart disease, stroke, and cancer.

Visceral versus abdominal subcutaneous fat and their relationship to insulin resistance:

 

Common causes of insulin resistance

This is not an exhaustive list:

• Muscle Mass: Low muscle mass reduces insulin sensitivity since skeletal muscle is one of the main organs that removes glucose from the blood. Age-related loss of muscle mass called sarcopenia appears to be associated with functional and molecular changes in the aging muscle that contribute to muscle insulin resistance.
• Physical Inactivity: a bit of a double-whammy as studies have demonstrated that independent of body composition, long periods of sedentary behaviours make you insulin resistant, and the resultant low muscle mass and higher body fat mass exacerbate this further.
• Stress Hormones: Cortisol and adrenaline induce insulin resistance akin to the fight-or-flight response. To help us survive blood levels of glucose and fatty acids need to be elevated. Fat cells immediately stop taking up glucose from the blood, and instead secrete fatty acids into the blood stream, glucose is released from the liver into the blood, and muscle tissue becomes less able to shift glucose from blood into our cells.
• Sleep Deprivation: has been shown to trigger insulin resistance through increased cortisol levels.
• Dysfunctional gut microbiome: research has demonstrated clearly that the types of bacteria we have in our gut, are strongly associated with insulin resistance.
• Menopause: Hormonal changes often lead to a shift in body fat distribution during menopause, with an increase in visceral fat mass even without any weight gain and are thought to contribute to declining insulin sensitivity independent of their effect on body fat mass and distribution.
• Diet: Dietary choices greatly affect insulin response and cell membrane function; consuming high amounts of saturated fats from animal sources, excessive fructose from added sugars, refined carbohydrates, and low fibre can lead to rapid blood sugar spikes, straining the pancreas and causing insulin resistance. Ultra-processed foods are typically rich in unhealthy fats, oils, salt, and lacking essential vitamins, minerals and fibre, thus worsening blood sugar whilst decreasing feelings of fullness.

Many of these factors are modifiable by our diet, level of physical activity and lifestyle.

For more advice, book an initial consultation at our Weight Loss Clinic.