Your fasting blood sugar was normal at your last physical. Your A1c was fine too. Yet you crash hard in the afternoon, crave sugar after meals, and carry weight around your middle that refuses to budge no matter how carefully you eat.
Those pieces can fit together into one picture, even when your blood sugar looks perfectly normal.
I talk about insulin resistance with patients in New Port Richey every week, because it sits underneath so many of the concerns they come in with: weight gain, fatigue, hormone changes, and heart risk. The signs of insulin resistance often show up years before blood sugar rises, and catching them early gives you the most room to turn things around.
What Is Insulin Resistance?
The short answer
Insulin resistance means your cells respond poorly to insulin, so your body makes more of it to keep blood sugar normal. Early signs of insulin resistance include weight gain around the waist, energy crashes after meals, sugar cravings, skin tags, darkened skin patches, and high triglycerides, often years before blood sugar rises.
Insulin is the hormone that moves sugar from your blood into your cells for energy. When cells stop responding well, the pancreas compensates by pumping out more insulin. For a long time, that extra effort keeps blood sugar in the normal range, which is exactly why standard tests can miss it.
High insulin has effects of its own, though. It encourages fat storage, especially around the organs, and makes stored fat harder to burn. That is the root of insulin resistance weight gain, and it helps explain why eating less so often stops working.
How Common It Is
Adults with prediabetes who do not know they have it, according to the CDC. About 98 million American adults, more than 1 in 3, have prediabetes, and insulin resistance usually comes first.
The Early Signs Of Insulin Resistance
Weight settling around the middle
A growing waistline, even when overall weight changes little, is one of the most telling signs. Visceral fat and insulin resistance feed each other.
Crashes after meals
Feeling sleepy, foggy, or shaky an hour or two after eating, especially after carb-heavy meals.
Constant hunger for sugar and carbs
Strong cravings, feeling hungry again soon after eating, and trouble going long between meals.
Skin tags and darkened patches
Small skin tags on the neck or underarms, and velvety darkened skin in body folds, called acanthosis nigricans.
High triglycerides, low HDL
A cholesterol panel with high triglycerides and low HDL is a classic pattern linked with insulin resistance.
Cycle and hormone changes
In women, irregular cycles and PCOS are closely linked. In men, insulin resistance is tied to lower testosterone.
Fatty liver, high blood pressure, and a history of gestational diabetes also raise the likelihood. For women in midlife, falling estrogen makes cells less sensitive to insulin, which I explain in my article on menopause belly fat. For men, the link with low testosterone runs both ways, which I cover in my article on the signs of low testosterone.
The Tests That Catch It Early
Standard screening focuses on blood sugar, which is the last thing to change. That is why the signs of insulin resistance are so often missed. A fuller picture looks at insulin itself and the patterns around it.
Fasting glucose and A1c
Fasting glucose of 100 to 125 mg/dL or an A1c of 5.7 to 6.4 percent signals prediabetes. Both can stay normal for years while insulin climbs.
Fasting insulin test
Shows how hard your pancreas is working to keep blood sugar normal. Results vary between labs, so trends over time are especially useful.
HOMA-IR
A score calculated from fasting glucose and fasting insulin that estimates insulin resistance. There is no single universal cutoff, so it is read in context.
Triglycerides, HDL, and waist
A high triglyceride to HDL ratio and a waist above 35 inches for women or 40 inches for men point toward insulin resistance.
Fasting insulin is one of the tests that most often gets skipped, which I cover in my article on feeling tired with normal labs.
See a provider promptly if you notice
- Increased thirst and frequent urination
- Blurred vision, slow-healing cuts, or frequent infections
- Unexplained weight loss
These can be signs that blood sugar has already risen into the diabetes range.
What Drives Insulin Resistance
Genetics play a role, and so do a handful of everyday factors that are very changeable.
Excess visceral fat, too little muscle, low physical activity, diets heavy in refined carbs and sugary drinks, short or broken sleep, and chronic stress all push insulin sensitivity down. Hormone shifts contribute too. Perimenopause, low testosterone, and thyroid problems can all make insulin resistance worse. Poor sleep is one of the most underrated drivers, which I cover in my article on waking at 3 AM.
The encouraging part is that insulin resistance responds well to change. In the landmark Diabetes Prevention Program trial, people with prediabetes who aimed to lose 7 percent of their body weight and exercise 150 minutes a week cut their risk of developing type 2 diabetes by 58 percent.
How I Approach It In My Practice
When I see the signs of insulin resistance, I look beyond fasting glucose. We check fasting insulin, A1c, a lipid panel, liver markers, and, when relevant, hormones and thyroid function, and we measure your waist. Then we connect those results to your symptoms and history.
The plan usually centers on protecting and building muscle, steadying blood sugar through how you eat, improving sleep, and managing stress. For some patients, medication helps, including GLP-1 medications when weight is a major factor. I explain how to keep the results from those medications in my article on stopping semaglutide. You can learn more on our medical weight loss page and our functional medicine page.
What You Can Do Starting Now
- Measure your waist
Measure at the belly button. Above 35 inches for women or 40 inches for men is a reason to look closer.
- Build meals around protein and fiber
Pair carbohydrates with protein, fiber, and healthy fat to blunt blood sugar spikes and the insulin surges that follow.
- Cut back on sugary drinks
Soda, sweet tea, juice, and specialty coffee drinks are among the fastest ways to spike insulin.
- Walk after meals
A 10 to 15 minute walk after eating helps your muscles pull sugar out of your blood.
- Strength train two to three times a week
More muscle means more places to store blood sugar and better insulin sensitivity.
- Ask for a fasting insulin test
If your symptoms fit, ask your provider about fasting insulin alongside glucose and A1c at your next blood draw.
Frequently Asked Questions
What are the first signs of insulin resistance?
The earliest signs of insulin resistance are often weight gain around the waist, energy crashes or brain fog after meals, strong sugar and carb cravings, skin tags, and darkened skin in body folds. Lab clues include high triglycerides and low HDL, often while fasting glucose and A1c are still normal.
Can you have insulin resistance with normal blood sugar?
Yes. For years, the pancreas can make extra insulin to keep blood sugar in the normal range, so fasting glucose and A1c may look fine. A fasting insulin test, the HOMA-IR calculation, and your triglyceride and HDL levels can reveal insulin resistance before blood sugar rises.
Can insulin resistance be reversed?
In many cases, it can be improved significantly. Losing some waist fat, building muscle, eating fewer refined carbs, walking after meals, and sleeping better all improve insulin sensitivity. In the Diabetes Prevention Program, lifestyle changes cut the risk of developing type 2 diabetes by 58 percent.
What is a normal fasting insulin level?
There is no single agreed optimal number, and results vary between labs because insulin tests are not fully standardized. Your provider should read fasting insulin alongside your glucose, the HOMA-IR score, triglycerides, waist size, and symptoms. Tracking the trend over time is often more useful than one result.
Does insulin resistance cause belly fat?
It contributes. High insulin levels encourage fat storage, especially deep in the abdomen, and that visceral fat makes insulin resistance worse, creating a cycle. Hormone changes in midlife, poor sleep, and muscle loss can intensify it. Breaking the cycle usually takes several changes working together.
Catch It Early, Change The Course
The signs of insulin resistance often build quietly for years. Finding it early, while blood sugar is still normal, gives you the best chance to reverse the trend and protect your long-term health.
Find out what your labs are really saying
Book a free 15-minute discovery call to talk about your symptoms and the tests that fit. We see patients in our New Port Richey office and by telemedicine throughout Florida, Nevada, and Arizona.
Book Your Free ConsultPrefer to talk today? Call (727) 312-4042