Insulin Resistance: The Hidden Barrier to Weight Control

(Part 1 of 3 in our Insulin Resistance Series)

For years, weight gain was explained away as “too many calories in, not enough burned off.” People were told they simply lacked willpower, or needed to try harder with diets and exercise. But science has shifted. We now understand that for many people, a deeper biological problem is at play — one that drives hunger, weight gain, and even weight regain after surgery. That problem is insulin resistance.

What is Insulin Resistance?

Insulin is a hormone made by the pancreas. Its main role is to help move sugar from the blood into your cells, where it can be used for energy. But when cells stop responding properly, the body has to make more and more insulin to get the same effect.

This “overproduction” keeps blood sugar in check for a while — but it also keeps insulin levels high. And insulin is a fat-storage hormone. High insulin means it’s harder to burn stored fat and easier to gain weight. It’s like trying to lose weight with the brakes on.

Signs and Symptoms You Might Notice

Insulin resistance doesn’t usually show up on a standard GP blood test. Instead, it creeps in with day-to-day struggles people often blame on themselves:

• Feeling hungry soon after eating

• Needing snacks to keep going

• Mid-afternoon energy crashes

• Brain fog and poor concentration

• Weight piling on around the middle

• Struggling to lose weight despite effort

• Skin changes such as small tags or darker patches in body folds

• Borderline high blood pressure or cholesterol changes

If these feel familiar, you’re not alone. They’re all part of the same metabolic picture.

Why Surgery Alone Isn’t Always Enough

Weight loss surgery is powerful — gastric sleeve, bypass, and other procedures help reduce appetite and food intake. But if insulin resistance is active, it can still blunt results. Some patients notice cravings returning, grazing behaviour, or slower improvements in HbA1c even after surgery.

This isn’t failure. It’s physiology. Surgery helps, but insulin resistance must be addressed too.

The Good News: Insulin Resistance Can Improve

The hopeful message is that insulin resistance is not permanent. With the right treatment and support, people often see:

• Reduced cravings

• More stable energy throughout the day

• Steadier weight loss

• Better blood test results (HbA1c, cholesterol, blood pressure)

It’s about working with your biology, not against it.

What’s Next

This is the first in a three-part series:

• Part 2 will explore how insulin resistance is measured — and why it’s often missed in the UK.

• Part 3 will focus on practical steps to reduce insulin resistance, especially after bariatric surgery.