Elizabeth Berrett
If you’ve been collecting chronic health problems the way golfers collect swing thoughts—one more each week, none of them helping—Hanna Purdy has a blunt question: have you considered insulin resistance as the uninvited caddie dragging your bag uphill?
Purdy is a nurse practitioner, public health specialist and author who argues that what we eat doesn’t just influence energy and weight—it can steer hormones, inflammation, and long-term disease risk. Her central thesis is unapologetically lifestyle-led. “Almost always with any chronic condition, there is something in our lifestyle causing it,” she says. “When digging deeper, it is obvious that one of the most important, if not the main, cause is the food we eat.”
This is not a tale of one villainous ingredient and a miracle cure. It’s a story about blood sugar regulation, metabolic health, and how modern eating patterns—processed food, frequent snacking, and heavy carbohydrate loads—may push the body towards chronic inflammation, fatigue, cravings, and a cascade of symptoms that feel unrelated until someone joins the dots.
Insulin resistance: the mechanism most people don’t see
Insulin is not the enemy. It’s essential. Purdy describes it as a hormone with “many roles in the metabolism,” primarily helping move glucose from the bloodstream into cells to be used for energy, while keeping blood glucose stable.
“In insulin resistance, the cells aren’t responding to the effects of insulin like they should,” she says, pointing to a common pattern: long-term over-consumption of sugary and starchy foods, plus eating too often.
Her explanation is simple, and a little ominous: “We have insulin in our body all the time, which leads to cells developing resistance to the effects. A consequence is that the pancreas produces an abnormally large amount of insulin to try to overcome the resistance of the cells, as an attempt to keep blood-sugar levels stable.”
That persistent elevation can lead to hyperinsulinemia—chronically high insulin—often discussed alongside metabolic syndrome. And once you’re in that loop, weight management, energy stability, and appetite regulation can start behaving like a putter with a loose head: unpredictable at best, expensive at worst.
Why it matters beyond diabetes
Many people file insulin resistance under “diabetes territory” and move on. But the condition sits upstream of several outcomes and is discussed as distinct from diabetes itself.
As the National Severe Insulin Resistance Service explains, people “with severe insulin resistance are those whose bodies respond least well to insulin”. Although many people with severe insulin resistance will go on to develop diabetes, it states that “severe insulin resistance is not the same as diabetes”.
Purdy’s concern is that even without a diabetes diagnosis, high insulin levels may still be linked with a long list of health issues—particularly those stubborn, overlapping chronic health problems that feel like they’re multiplying.
The body-wide knock-on effects: weight, pain, hormones, brain health
Purdy describes insulin as a storage signal—especially for fat storage—so persistently high insulin can make fat loss feel like pushing a trolley with a wonky wheel.
“We put on weight because insulin stores the excess glucose we eat as fat,” she explains. “Because of this, if there’s too much insulin, the task of losing weight is almost impossible, as the opposite hormone – glucagon – no longer has any effect, therefore fat-burning isn’t possible.
“Insulin resistance is known to cause chronic inflammation, which affects all tissues around the body and can lead to many chronic symptoms and illnesses, from chronic aches and pains, dental problems and osteoporosis, to type 2 diabetes and heart disease,” she adds.
She also flags reproductive and endocrine links—PCOS, thyroid problems, early puberty—and notes it can be “a big problem during menopause, when hormones are in turmoil already.”
Later-life risks enter the conversation too, with Purdy pointing to neurological associations: “The brain is affected by this condition just like any other organ. Alzheimer’s disease has been referred to as ‘type 3 diabetes’ – diabetes of the brain. In addition, we also know many other neurological problems have been associated with insulin resistance.”
And it’s not only an older person’s issue. Purdy argues metabolic risk can begin before birth, describing how maternal glucose and fetal insulin response may influence later outcomes: “During pregnancy, too much glucose in the mother’s body can cause the pancreas of the foetus to release increasing amounts of insulin,” explains Purdy, “meaning these babies suffer from hyperinsulinemia before they’re even born, causing changes in their gene expression, inflammation and increasing size of the baby and the placenta. This increases the risk of metabolic symptoms later in life.”
The symptom checklist: when “just tired” might be a clue
The problem with many chronic health problems is that they present like background noise—tiredness, cravings, mood swings—and become “normal” by repetition.
Purdy says the most common sign is excess weight and/or fat around the middle. She also points to low blood-sugar crashes between meals, tiredness and low energy, irritability, mood swings, food cravings, low immunity and frequent infections, snoring, skin problems, inflammatory conditions, raised blood pressure, and water retention.
Her view is that insulin resistance is widespread enough to be considered a major root cause for many symptom clusters. “Insulin resistance is such a common condition and causes so many problems around the body, that if we suffer from any symptoms, it’s very likely to be at least one of the major root causes,” says Purdy. “For this reason, it would be extremely important to reverse insulin resistance to get better with any condition.”
The practical plan: what Purdy says actually helps
Purdy’s approach is anchored in dietary change, supported by exercise, sleep, and stress management. She advises reducing sugar and carbohydrate intake—while emphasising caution for people with existing medical issues and the importance of professional guidance.
Her key recommendations include:
- Avoiding grains such as bread, pasta, and cereals (which break down into sugar)
- Cutting back processed food
- Not eating too often—she suggests a maximum of three times a day—to support the insulin/glucagon balance
On what to eat, she points towards nutrient-dense whole foods: organic vegetables, herbs and berries, gut-supporting fermented foods (probiotics), and prebiotic-rich produce such as berries, apples, cabbage, broccoli, onions and garlic. She also highlights omega-3 sources like oily fish.
Exercise matters, particularly for improving insulin sensitivity via muscle gain. And while “any exercise is beneficial,” she notes research support for HIIT in improving insulin sensitivity.
Lifestyle levers beyond food are non-negotiable in her framework: managing stress, prioritising sleep, stopping smoking/vaping, and avoiding alcohol.
“These measures will reduce the amount of insulin in the body, which results in the reduction of symptoms very quickly, and we burn excess fat, including around the liver,” says Purdy. “All these measures also reduce chronic inflammation in the body very effectively, and boost the immune system.”
Stress: the sabotage factor most plans ignore
If food is the main driver, stress can still hijack the steering wheel.
While Purdy stresses diet is the biggest lever, she names chronic stress as a key contributor: “One of the important ones is chronic stress,” she says. “High levels of stress hormones affect the overall hormonal balance, including insulin, so constant stress can actually sabotage our efforts to reverse insulin resistance, even if our diet is reasonably healthy.”
In other words: you can overhaul the pantry and still struggle if your nervous system is living in permanent emergency mode—sleep-deprived, overstimulated, and running on cortisol.
Who is this best for?
- People dealing with persistent fatigue, cravings, central weight gain, energy “crashes,” or a cluster of chronic health problems that don’t seem connected
- Readers who want a lifestyle-first framework for metabolic health (blood sugar control, inflammation reduction, hormone stability)
- Those ready to change eating patterns (including meal timing) rather than chasing a single supplement or quick fix
Is it worth it?
At £14.99, the value hinges on whether you’ll act on the fundamentals: reducing ultra-processed food, rethinking sugar and refined carbs, spacing meals, training consistently, and taking stress and sleep seriously. If you’re looking for a credible explanation of insulin resistance—and a practical, habit-based route to improving metabolic health—the proposition is straightforward: inexpensive compared to the medical and emotional cost of unmanaged chronic health problems.
Could It Be Insulin Resistance? by Hanna Purdy is published by Hammersmith Books, priced £14.99. Available now.
