PCOS & the body’s silent protest to weight loss
What is the first thought that comes to mind when you see an overweight woman? That she is indolent? Lacks the willpower to exercise? Isn’t disciplined enough to stick to a diet? Or that there may be an underlying medical issue?
If your instinct was one of the first three, you wouldn’t be alone. Even those entrusted with healing, healthcare providers trained in physiology and metabolic disorders, often internalise and act upon the same biases as the general public. Research using Implicit Association Tests (IATs) has shown that many clinicians subconsciously associate obesity with laziness or noncompliance, despite their scientific training.
Society has systematically engrained weight-based stereotypes—such as the aforementioned association of obesity with laziness—through repeated exposure in media, education, and even healthcare narratives. These biases are often absorbed implicitly from a young age, becoming part of our unconscious judgment frameworks, regardless of scientific accuracy.
Today, I want to draw attention to one of the often overlooked, underlying causes of weight gain and resistance to weight loss: Polycystic Ovary Syndrome (PCOS). PCOS is a complex hormonal disorder affecting approximately one in ten women of reproductive age, and it significantly disrupts metabolic, reproductive, and endocrine functions. For many individuals with PCOS, losing weight is not simply a matter of willpower but one of physiological rebellion. For example, their basal metabolic rate is up to 40% lower than women without the condition, meaning they burn significantly fewer calories at rest. But this is only one part of the larger picture. To understand this rebellion, we must explore the very mechanisms that make weight loss not only difficult, but biologically opposed.
The first thing to understand about PCOS is that, like weight loss, it’s heterogeneous: no two people experience it the same. Symptoms range widely in type and intensity depending on body mass index (BMI), insulin sensitivity, androgen levels, genetics, and lifestyle factors like diet, stress, and sleep. Some experience irregular periods while others struggle with infertility, excess body hair, or stubborn weight gain. While I can’t cover every form of PCOS, I’ll focus on the most common presentation, where insulin resistance is the spark that ignites a full-blown hormonal rebellion.
Insulin is an anabolic hormone secreted by the pancreas, primarily to maintain glucose homeostasis. It tells the muscles to take in glucose and build protein, instructs fat cells to store glucose and fatty acids while halting fat breakdown, and signals the liver to stop producing glucose. These actions are carried out via two major signaling pathways:
- The PI3K/AKT pathway, responsible for metabolism—glucose uptake, glycogen and fat synthesis, and
- The MAPK/ERK pathway, responsible for cell growth and protein synthesis.
In cases of insulin resistance, the PI3K/AKT pathway is disrupted due to faulty phosphorylation of IRS (Insulin Receptor Substrate) proteins, while the MAPK/ERK pathway remains active, promoting fat storage and androgen excess. These androgens act like rogue agents, infiltrating multiple systems:
- In the ovaries, they disrupt LH and FSH balance, sabotaging ovulation.
- In the liver, they reduce SHBG (sex hormone-binding globulin), allowing free testosterone to wreak more havoc.
- In adipose tissue, they increase visceral fat storage, particularly in the abdomen.
- In the brain, they interfere with appetite and mood-regulating hormones like ghrelin, leptin, and serotonin.
This internal rebellion also causes chronic low-level inflammation (precipitating more rogue androgens), drops basal metabolic rate, and causes fat to be stored rather than burned. Blood sugar rises. Cravings spike. The body holds onto weight like it’s preparing for war, and losing it becomes physiologically harder, not just psychologically.
This is not failure—it’s a hormonal insurgency misread as laziness. In this civil war, the body isn’t betraying you; it’s resisting a system that no longer works.