Insulin resistance silently shapes the trajectory of nearly every major chronic disease, yet it’s often overlooked until blood sugar abnormalities become obvious. In this episode, Dr. Ben Bikman exposes the dietary culprits that drive metabolic dysfunction and highlights actionable, evidence-based tactics for improving metabolic health. Ben also addresses pressing questions about popular weight loss medications like Ozempic and other GLP-1 agonists: Are they groundbreaking solutions, or shortcuts with hidden metabolic consequences?
Ben Bikman has a provocative suggestion for modern medicine: insulin levels should be routinely measured in clinical settings.
Modern medicine has a “glucose-centric” approach to disease management, often measuring and prioritizing blood glucose levels at the expense of other potentially more relevant biomarkers.
The problem is that normal blood sugar levels can mask the more sinister and debilitating problem of insulin resistance.
Insulin is a peptide hormone produced and secreted by the beta cells (β-cell) of the pancreas (islets of Langerhans). It plays a central role in glucose homeostasis by facilitating cellular uptake of glucose, particularly in skeletal muscle and adipose (fat) tissue, and by suppressing liver glucose production (gluconeogenesis and glycogenolysis).
There are few cells and tissues in the body that insulin doesn’t affect. In addition to regulating glucose metabolism, insulin has wide-ranging anabolic effects across multiple systems. Among its many actions are:
- Stimulating glycogen synthesis in liver and muscle.
- Promoting lipogenesis (fat storage) by increasing fatty acid and triglyceride synthesis, while inhibiting lipolysis (fat breakdown).
- Stimulating amino acid uptake and protein synthesis in muscle and inhibiting protein breakdown.
- Regulating electrolyte balance and ion concentrations within our cells.
- Stimulating growth and proliferation (especially during fetal development and puberty).
- Promoting nitric oxide (NO) production to support endothelial health and function.
- Modulating appetite, neurotransmission, and cognitive processes through its actions on the central nervous system.
The secretion of insulin is tightly regulated, primarily in response to elevated blood glucose, but also by amino acids, incretin hormones (GLP-1, GIP), neural inputs, and other circulating factors.
Dr. Ben Bikman is primarily interested in what happens when the body stops responding to insulin—what’s known as insulin resistance. Insulin resistance occurs when the body requires higher-than-normal levels of insulin to maintain blood glucose. This means that normal blood glucose levels can mask insulin resistance. A person can maintain seemingly normal blood glucose levels because the body compensates by producing higher levels of insulin.
Without measuring insulin directly, clinicians can miss early warning signs and, by prescribing more insulin to treat high glucose levels, make insulin resistance worse instead of better!
General representation of the insulin and blood glucose response in someone with normal insulin sensitivity and someone with insulin resistance.
How to Detect Early Signs of Insulin Resistance
Ben Bikman is an advocate of continuous glucose monitoring or CGM. He believes that democratizing access to these devices can put people in a position to be their own coach and understand their metabolic health by seeing how the body is responding to what they eat.
What makes CGMs useful is that they measure dynamic glucose levels rather than a static snapshot. Unlike fasting glucose measures, dynamic glucose responses such as those after meals provide immediate insight into how the body manages glucose after carbohydrate intake.
For example, a healthy, insulin-sensitive person’s glucose levels typically return to normal within 2 hours of eating a carbohydrate-containing meal. If glucose levels remain elevated beyond this window, it could indicate potential insulin resistance.
Can Our Skin Provide a Window Into Metabolic Health?
In addition to monitoring glucose, the skin can often be a “window into the metabolic soul.” Specifically, there are two skin conditions that indicate underlying insulin resistance.
- Acanthosis nigricans: Acanthosis nigricans is a skin condition characterized by dark, velvety, thickened patches of skin, most often appearing in body folds like the neck, armpits, groin, and under the breasts
What causes it?
It results from overstimulation of skin cells (keratinocytes and dermal fibroblasts) by high levels of circulating insulin. Excess insulin can bind to insulin-like growth factor (IGF) receptors in the skin, triggering abnormal skin growth and pigmentation.
- Skin tags: Skin tags are small, soft, flesh-colored or slightly darker growths commonly found on the neck, armpits, eyelids, groin, and under the breasts
What causes it?
People with multiple skin tags—especially if they appear suddenly or in large numbers—often show signs of insulin resistance or metabolic syndrome. As with acanthosis nigricans, high insulin levels seem to stimulate skin cell growth and possibly promote collagen overproduction in certain areas.
Both conditions are benign, meaning they are not dangerous themselves, but they can serve as clinical red flags for underlying insulin resistance and other metabolic issues. Indeed, the prevalence of acanthosis nigricans and skin tags is higher in people with obesity, high fasting insulin, and type 2 diabetes—some studies report that 60–75% of adults with obesity also have acanthosis nigricans, for example. However, when insulin levels fall after weight loss, better nutrition, and exercise, these skin conditions regress or reverse completely.
Acanthosis nigricans and the insulin pathway. Eggiman, E., et al. DOI: 10.1007/s44337-024-00017-7. Used under Creative Commons license 4.0 (CC BY 4.0)
