Insulin Resistance, its impact on your ability to lose weight, and how GLP-1 medications can help
Let's not lie... when you're trying to lose weight, it can be a frustrating journey, especially when your body seems to resist your best efforts. One key factor that is often unknown is insulin resistance. This condition affects how your body processes sugar and can make losing weight much harder... just what you want to hear!
Fortunately, new treatments like GLP-1 medications, that have grown in the UK market, offer hope, even if insulin resistance is part of the challenge. This article explores what insulin resistance is, how it impacts weight, and why GLP-1 medications may help you achieve your weight loss goals.
What is Insulin?
Insulin is a hormone produced by the pancreas that helps your body use glucose (sugar) from the food you eat for energy. When your cells respond well to insulin, glucose moves from your bloodstream into your cells efficiently. Insulin resistance happens when your cells stop responding properly to insulin. This means glucose stays in your blood instead of being absorbed, causing your pancreas to produce even more insulin to compensate.
Over time, this extra insulin can lead to higher blood sugar levels and may eventually cause type 2 diabetes. Insulin resistance is often linked to excess body fat, especially around the abdomen, but it can also develop due to genetics, inactivity, or poor diet.
How can insulin resistance make weight loss harder?
Insulin resistance means that the body's cells don't respond as effectively to insulin. The pancreas may therefore need to produce more insulin to keep blood glucose under control. Diabetes UK notes that severe insulin resistance can be associated with higher insulin levels and can contribute to weight gain.
There is an important distinction, though: insulin resistance does not make weight loss biologically impossible. Rather, it can be part of a feedback loop that makes weight management more difficult.
A simplified version looks like this:
Insulin resistance → higher insulin requirements → greater difficulty regulating appetite, glucose and fat storage → weight gain/maintenance → worsening insulin resistance.
But the relationship goes in both directions. Diabetes UK specifically says that, for people living with overweight or obesity, weight loss can improve the way the body uses insulin, while increasing physical activity can also improve insulin sensitivity.
This is one reason that someone can find that losing weight is considerably harder than another person's experience, even when both are making apparently similar lifestyle changes. Insulin resistance can also occur in people who are not overweight, so it shouldn't be assumed simply from someone's body size.
How Insulin Resistance Affects Your Weight and Weight Loss
Insulin resistance creates a cycle that makes losing weight difficult:
Increased fat storage: High insulin levels promote fat storage, especially in the belly area. Insulin signals your body to store energy rather than burn it.
Reduced fat burning: When insulin is high, your body is less likely to use stored fat for energy.
Increased hunger: Insulin resistance can disrupt hormones that control appetite, leading to increased hunger and cravings, especially for sugary or high-carb foods.
Slower metabolism: Insulin resistance may slow down your metabolism, making it harder to burn calories efficiently.
Because of these effects, people with insulin resistance often find that traditional weight loss methods like dieting and exercise don’t work as well. They might lose weight initially but then hit a plateau or regain weight quickly.
Signs You Might Have Insulin Resistance
You may have insulin resistance if you experience:
Difficulty losing weight despite diet and exercise
Fat accumulation around the waist
High blood sugar or prediabetes diagnosis
High blood pressure or cholesterol levels
Skin changes such as dark patches (acanthosis nigricans) on the neck or underarms
If you suspect insulin resistance, it’s important to talk to a healthcare professional who can perform tests and recommend appropriate treatment.
How GLP-1 Medications Help with Weight Loss Despite Insulin Resistance
GLP-1 (glucagon-like peptide-1) medications are a newer class of drugs originally developed to treat type 2 diabetes. They mimic a hormone in your gut that helps regulate blood sugar and appetite. These medications have shown promising results in helping people lose weight, even when insulin resistance is present.
Here’s how GLP-1 medications support weight loss:
Improve insulin sensitivity: GLP-1 drugs help your body use insulin more effectively, lowering blood sugar and insulin levels.
Reduce appetite: They act on the brain to reduce hunger and cravings, making it easier to eat less without feeling deprived.
Slow stomach emptying: This helps you feel full longer after meals, reducing overall calorie intake.
Promote fat loss: Some studies suggest GLP-1 medications may help reduce fat mass, particularly around the abdomen.
Because GLP-1 medications target multiple factors involved in insulin resistance and weight gain, they can break the cycle that makes weight loss so challenging.
What should you eat?
The practical objective isn't to eliminate carbohydrates or follow an extremely restrictive "insulin-lowering" diet. The NHS position is that there isn't one perfect diet for weight loss; the important thing is finding an eating pattern that reduces overall energy intake while remaining nutritious and sustainable.
For someone concerned about insulin resistance, I'd structure meals around:
There is an important distinction, though: insulin resistance does not make weight loss biologically impossible. Rather, it can be part of a feedback loop that makes weight management more difficult.
But the relationship goes in both directions. Diabetes UK specifically says that, for people living with overweight or obesity, weight loss can improve the way the body uses insulin, while increasing physical activity can also improve insulin sensitivity.
Protein: eggs, fish, chicken, lean meat, Greek yoghurt, cottage cheese, tofu, beans and lentils.
High-fibre vegetables: particularly non-starchy vegetables such as broccoli, cauliflower, peppers, spinach, mushrooms, courgettes and green beans.
High-fibre carbohydrates: oats, beans, lentils, wholegrains, potatoes with their skins and other minimally processed carbohydrate sources.
Fruit: whole fruit rather than relying heavily on juices or sugary drinks.
Healthy fats in sensible quantities: nuts, seeds, olive oil and avocado.
Water and low/no-calorie drinks rather than regularly consuming sugary drinks.
The NHS recommends including protein with meals and filling around half of the plate with vegetables because vegetables provide fibre and can help with fullness.
What about carbohydrates?
Carbohydrates aren't inherently the problem. The type, quantity and overall dietary pattern matter.
For someone with insulin resistance, a meal such as:
chicken + large portion of vegetables + lentils + small amount of olive oil
is quite different metabolically and in terms of satiety from:
sugary cereal + toast + fruit juice
even though both contain carbohydrate.
A useful principle is therefore "higher-fibre, minimally processed carbohydrates in appropriate portions", rather than "no carbohydrates".
Other Practical Tips for Managing Insulin Resistance and Supporting Weight Loss
While medications can help, lifestyle changes remain essential for managing insulin resistance and improving weight loss outcomes. Consider these strategies:
Focus on whole foods: Choose vegetables, fruits, whole grains, lean proteins, and healthy fats. Avoid processed foods high in sugar and refined carbs.
Exercise regularly: Aim for a mix of aerobic activities and strength training to improve insulin sensitivity and build muscle.
Manage stress: Chronic stress can raise blood sugar and insulin levels. Techniques like meditation, yoga, or deep breathing can help.
Get enough sleep: Poor sleep affects hormones that regulate appetite and insulin.
Monitor portion sizes: Eating smaller, balanced meals throughout the day can help control blood sugar spikes.
When to Consider GLP-1 Medications
GLP-1 medications are prescription drugs and not suitable for everyone. They are usually recommended for people with type 2 diabetes or obesity who have not achieved sufficient weight loss through lifestyle changes alone.
Some common GLP-1 drugs include Liraglutide, Tirzepatide and Semaglutide. They are generally well tolerated but can have side effects like nausea or digestive discomfort. Regular follow-up is important to monitor progress and adjust treatment.
Where does Mounjaro & Wegovy fit in?
This is where the newer medications become particularly interesting.
Wegovy — semaglutide
Wegovy contains semaglutide, a GLP-1 receptor agonist.
It mimics the action of GLP-1, a hormone involved in appetite and blood-glucose regulation. For weight management, semaglutide reduces appetite and increases feelings of fullness; it also slows digestion.
In practical terms, this can make the calorie deficit required for weight loss considerably easier to maintain because the person may experience:
chicken + large portion of vegetables + lentils + small amount of olive oil
less hunger between meals
earlier fullness
fewer cravings or urges to eat
smaller natural portions
less mental preoccupation with food.
NICE recommends semaglutide (Wegovy) alongside a reduced-calorie diet and increased physical activity for eligible adults with obesity/weight-related health problems.
Mounjaro — tirzepatide
Mounjaro is slightly different.
Its active ingredient is tirzepatide, which activates both GIP and GLP-1 receptors. NHS guidance describes it as reducing appetite and increasing fullness, while also slowing digestion and helping regulate blood glucose.
So Mounjaro isn't simply "an insulin drug". Its weight-loss effect is substantially related to appetite and energy-intake regulation, alongside its effects on glucose metabolism.
NICE recommends tirzepatide for eligible adults with obesity alongside a reduced-calorie diet and increased physical activity.
The connection between GLP-1's and insulin resistance...
This is perhaps the most useful way to think about the whole subject:
Insulin resistance can make the metabolic environment associated with excess weight more difficult to manage.
Weight loss can improve insulin sensitivity.
GLP-1/GIP medicines can make achieving that weight loss easier by reducing appetite and increasing satiety.
The resulting weight loss can, in turn, improve metabolic health and insulin sensitivity.
So the medication isn't necessarily "overcoming insulin resistance" in the simplistic sense. It is helping address several parts of the physiological problem—particularly appetite, food intake, glucose regulation and, with weight loss, insulin sensitivity.
Diabetes UK itself identifies weight loss, healthy eating and exercise as ways of improving insulin resistance.
An important caveat...
It would be misleading to describe insulin resistance as the sole reason someone struggles to lose weight. Weight regulation is influenced by appetite biology, genetics, sleep, activity, medications, hormones, environment, eating patterns and many other factors. The NHS explicitly notes that many factors can affect weight-loss progress.
Likewise, Mounjaro and Wegovy aren't substitutes for nutrition. NHS guidance specifically says they should be used alongside a balanced, reduced-calorie diet and physical activity.
That becomes particularly important during substantial weight loss: if appetite is dramatically reduced, the emphasis should shift toward getting enough protein, fibre, micronutrients and other essential nutrients, rather than simply trying to eat as little as possible.
So basically...
You can think of it as:
Insulin resistance - The body doesn't respond as effectively to insulin↓Can be associated with increased hunger, metabolic dysfunction and difficulty managing weight.
Improving insulin sensitivity becomes part of the goal↓Weight loss + physical activity + appropriate nutrition can improve insulin sensitivity↓GLP-1/GIP medications can make weight loss more achievable for eligible people by reducing appetite and increasing fullness
The resulting weight loss can further improve metabolic health.
And importantly, this isn't about blaming someone for having "bad insulin". Insulin resistance is a physiological condition, and Diabetes UK notes that its causes are complex and aren't completely understood.
If you're looking at this specifically from the perspective of "why am I struggling to lose weight despite eating reasonably well?", the next useful step is to distinguish insulin resistance, insulin levels, blood glucose/HbA1c, appetite and calorie intake, because they're related but aren't interchangeable.
Summary
Insulin resistance can make weight loss a tough challenge by increasing fat storage, slowing metabolism, and boosting hunger. Understanding this condition helps explain why some people struggle despite their best efforts. GLP-1 medications offer a valuable tool by improving insulin sensitivity, reducing appetite, and promoting fat loss. Combined with healthy lifestyle changes, they can help break the cycle of insulin resistance and support sustainable weight loss.
If you suspect insulin resistance is affecting your weight, let us know so we can advise appropriately and see how we can help you. Taking action today can improve your health and make your weight loss journey more successful.
Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Consult your healthcare provider before starting any new treatment or medication.
