What are the symptoms of insulin resistance in men?

The most common are: weight accumulating around the midsection despite stable habits, afternoon energy crash after meals, cravings for carbohydrates or sweet things that are unusually intense, fatigue that is disproportionate to activity level, and brain fog. These symptoms often predate an elevated glucose reading by years.

Can you have insulin resistance with normal blood sugar?

Yes. In insulin resistance, the pancreas compensates by producing more insulin to keep blood sugar in range. The blood sugar appears normal. The elevated insulin is doing the compensatory work. A fasting insulin test reveals the resistance before the glucose does.

How is insulin resistance diagnosed?

Fasting glucose alone is insufficient. Fasting insulin combined with fasting glucose, or a fasting insulin with a calculated HOMA-IR index, is more sensitive. A fasting insulin above 10 uIU/mL with normal glucose suggests developing resistance. A HOMA-IR above 2.0 is generally considered indicative of resistance.

The System Gap

Insulin Resistance Symptoms in Men. We Miss Them Because We Look Fine.

Insulin resistance develops for years before glucose rises. A cardiologist names the signs men miss and the test that catches it first.

Job Mogire, MD, FACP, FACC · Medically reviewed June 14, 2026

The Insulin Resistance Atherosclerosis Study, published in 1997 and following over 1,600 adults across multiple clinical centers, established two things clearly: insulin resistance precedes type 2 diabetes by years, and it independently predicts cardiovascular events regardless of what the glucose reads at the time of the visit. The man reading this probably had a normal glucose at his last physical. That finding, on its own, tells him almost nothing about where his cardiovascular risk is heading.

He is not sick. He is fine. His fasting glucose came back at 94. His A1C is 5.3. His physician looked at the panel and said everything looks good. He weighs about fifteen pounds more than he did at forty, most of it in the belly, but he attributes that to getting older and not getting to the gym as much. He gets tired in the afternoons but he works hard and he does not sleep enough and that is probably all it is. He is not the kind of person who has a metabolic condition. He is just busy.

He may have had insulin resistance for three to five years.

Approximately one in three adults in the United States has insulin resistance, according to CDC and NHANES surveillance data. Most are undiagnosed. Most have a recent normal glucose. The glucose is not the right test for what is happening to them yet.

The Mechanism

Insulin resistance does not begin with an elevated glucose reading. It ends there, years later, after the pancreas has been compensating silently.

The sequence starts in the liver, muscle, and fat tissue. These cells become progressively less responsive to insulin’s signal to take up glucose from the bloodstream. The signal is being sent. The cells are not responding at full efficiency. The pancreas detects that blood glucose is not being cleared properly and does the only thing it can: it produces more insulin. In early to moderate insulin resistance, the pancreas will produce two to three times the normal amount of insulin to maintain blood glucose within the reference range. The glucose reads 94. The lab report says normal. The fasting insulin, which was not ordered, is sitting at 16.

This compensated phase can last a decade. During that decade, the elevated circulating insulin is doing significant metabolic work that has nothing to do with glucose control.

Elevated insulin drives sodium retention and increases blood pressure. It directly promotes visceral fat storage, meaning fat deposited inside the abdominal cavity around the liver, pancreas, and intestines, rather than the subcutaneous fat that accumulates just under the skin. Jensen and colleagues, writing in the Journal of Clinical Investigation in 2002, identified visceral fat as the primary site of excess free fatty acid release that impairs hepatic insulin signaling, creating a self-reinforcing cycle: insulin resistance promotes visceral fat accumulation, and the visceral fat deepens the insulin resistance.

The elevated insulin also generates low-grade systemic inflammation. Visceral fat is not inert. It is metabolically active tissue that produces interleukin-6, tumor necrosis factor-alpha, and plasminogen activator inhibitor-1. These are not abstract molecules. IL-6 and TNF-alpha drive endothelial inflammation. PAI-1 impairs clot resolution and is independently associated with cardiovascular events. The man’s glucose is normal. His vascular environment is not.

The atherogenic lipid pattern assembles during this same period without any glucose abnormality to flag it. Elevated triglycerides, low HDL cholesterol, elevated ApoB, and the small dense LDL phenotype that does not appear on a standard LDL test. Reaven, writing in Arteriosclerosis in 1996, documented the triglyceride-to-HDL ratio as a cardiovascular risk marker in insulin-resistant populations. A fasting triglyceride above 150 mg/dL with HDL below 40 mg/dL is the lipid signature of insulin resistance even when glucose is entirely normal.

And elevated insulin suppresses sex hormone binding globulin. SHBG is the protein that carries testosterone through the bloodstream. When SHBG falls, total testosterone may look normal on a lab report while free bioavailable testosterone drops. The man who asks his physician about fatigue and low drive gets a total testosterone result that comes back in the lower half of normal and is told he is fine.

This is the mechanism. The symptoms it produces are real, physiological, and specific.

What the Evidence Shows

The midsection shift is not cosmetic and it is not random. The pattern most men describe is weight that accumulates in the abdomen specifically, often over two to four years, without a clear change in diet or overall activity. This is the visceral fat accumulation pattern driven by elevated insulin and altered cortisol metabolism. A waist circumference above 40 inches in men is the clinical threshold for visceral adiposity that correlates with HOMA-IR. The man who has not changed his habits but has added 15 pounds mostly in the belly is not experiencing normal aging uniformly. He is describing a specific metabolic signature. 4 / Promising

The afternoon energy crash has a precise physiological explanation. After a carbohydrate-containing meal in an insulin-resistant individual, the postprandial insulin response overshoots. The pancreas, already in a compensatory state of hyperinsulinemia, releases an exaggerated amount of insulin in response to the meal. Blood glucose rises, the insulin overshoot clears it faster than it should, and glucose falls below baseline. This reactive hypoglycemia produces the fatigue and hunger signal that arrives 90 to 120 minutes after eating. Ludwig’s research on postprandial insulin dynamics documented how this insulin overshoot drives subsequent hunger, particularly for fast-digesting carbohydrates. The man who is fully functional all morning and becomes foggy and hungry by 2:30 in the afternoon is describing this pattern with precision. He calls it the afternoon slump. It is postprandial insulin dysregulation. 4 / Promising

The carbohydrate craving is not a discipline failure. The brain requires a steady supply of glucose. Insulin receptors are present throughout the central nervous system, including in the hippocampus and prefrontal cortex. When peripheral tissues are resistant to insulin’s glucose-delivery signal, the brain is not receiving adequate glucose delivery and generates a hunger drive oriented toward fast-digesting carbohydrates. This is a signaling response to impaired glucose delivery, not a character deficiency. The hypothalamus maintains partial insulin sensitivity even in peripheral insulin resistance, and this selective sensitivity drives appetite signals. The man who finds himself craving sweets at 3pm despite having eaten lunch is responding to a physiological signal, not a willpower gap.

Fatigue disproportionate to activity level reflects mitochondrial impairment. In states of chronic elevated free fatty acids, which are released by visceral fat and impair insulin signaling, the mitochondrial electron transport chain becomes less efficient. Men with fasting insulin above 15 show measurably impaired post-exercise recovery in studies using DEXA and VO2 testing. The fatigue is not psychological. The energy production machinery is running less efficiently. The man who exercises regularly and consistently feels more drained than his training load should produce is not overtrained. He is metabolically inefficient in a way that responds to intervention.

Brain fog and cognitive friction are real effects of insulin resistance on the central nervous system. Craft and colleagues, writing in Archives of Neurology in 2000, documented that insulin resistance impairs cerebral glucose metabolism and that intranasal insulin temporarily improves cognition in early Alzheimer’s trials, suggesting a direct relationship between insulin signaling in the brain and cognitive function. The FINGER trial, a large randomized trial of lifestyle intervention targeting metabolic health, improved cognitive function scores in participants. The evidence here is mechanistically strong and early in terms of direct causal proof in otherwise healthy men. 3 / Early

Sexual function and testosterone are affected through the SHBG suppression mechanism described above. Kapoor and colleagues in 2006 documented the bidirectional relationship between testosterone deficiency and insulin resistance in men: low testosterone promotes insulin resistance, and insulin resistance suppresses SHBG and bioavailable testosterone. Men presenting with fatigue, reduced libido, and low-normal total testosterone who have never had a fasting insulin drawn are often in this cycle without knowing it. Erectile dysfunction in younger men deserves particular attention in this context: penile arteries are 1 to 2 millimeters in diameter. Endothelial dysfunction from insulin-driven inflammation and oxidative stress affects small-caliber arteries first, making erectile function one of the earliest functional signals of vascular compromise. 4 / Promising

The cardiovascular stake is the reason this matters beyond metabolic curiosity. The Helsinki Policemen Study followed men for 22 years and found that men in the highest insulin quartile had a 2.2 times greater cardiovascular event rate than men in the lowest quartile. The DECODE study, published by Barzilay and colleagues in 2001, confirmed that insulin resistance predicts cardiovascular mortality independent of glucose levels. The atherogenic lipid triad of elevated triglycerides, low HDL, and elevated ApoB, assembled during the compensated phase of insulin resistance, is a direct contributor to atherosclerotic plaque burden. The small dense LDL particles that dominate this pattern are more atherogenic per particle than the large buoyant LDL that a standard lipid panel measures. They do not show up as an elevated LDL. They require ApoB or LDL particle number testing to detect.

Cardiologist's Note

The man who comes into my office with these symptoms and a normal glucose almost always gets reassured before he reaches me. I understand why: the standard panel does not produce a number that requires action. The glucose is 94, the A1C is 5.3, and the physician tells him he is fine and to watch his diet. What the standard panel misses is that the glucose is normal because the pancreas is working twice as hard as it should be to keep it there. When I add a fasting insulin to the draw, I regularly see values between 15 and 25 in men whose glucose is entirely normal. A fasting insulin of 18 with a glucose of 94 gives a HOMA-IR of approximately 4.2. That is established insulin resistance. That man is not fine metabolically, even though every number the physician looked at was in range.

What I see clinically is a pattern that takes two to three visits to fully map. The first visit, the man presents with something else: fatigue, his wife wanted him to come in, or a routine physical that was overdue. The lipids come back with triglycerides at 180 and HDL at 38, which gets noted but rarely acted on aggressively when the glucose is normal. The second or third visit, the waist has grown another inch or two. He mentions the afternoon energy issue when I ask specifically. When I ask whether he is reaching for carbohydrates in the late afternoon, he looks at me like I have been following him around. He had not connected those things to a metabolic pattern. He attributed all of it to getting older.

The fasting insulin test costs almost nothing and is available at any standard lab. It is not on the standard metabolic panel. It will not be ordered unless someone asks for it. That is the gap. The physiology is well-described and decades old. The clinical gap is that the compensated phase is largely invisible to the tests we routinely run, and men in this phase are reassured when they should be warned.

What I tell men in this situation is that they have found something good: they are in the window where intervention is most effective and most reversible. The pancreas still has significant beta cell reserve. The glucose is still normal. The vascular damage is early and partially recoverable. This is not a diagnosis that requires medication yet. It requires a few specific changes executed consistently, and re-testing in three to four months. The men who do that consistently see their fasting insulin drop, their HOMA-IR normalize, their triglyceride-to-HDL ratio improve, and their afternoon energy pattern resolve. The men who wait until the glucose is elevated have moved past the easiest part of the intervention window.

What to Do This Week

Measure your waist at the navel, not the belt. Stand relaxed, exhale normally, measure at the level of the belly button with the tape horizontal. If the number is above 40 inches, that measurement alone justifies asking for fasting insulin at your next lab draw. The belt hides this measurement. The tape does not.
Request fasting insulin at your next lab visit, specifically. It is not included in the standard metabolic panel. You will need to ask for it by name. Ask for fasting insulin alongside fasting glucose. If both are available, your physician or a calculator can derive HOMA-IR. A fasting insulin above 10 uIU/mL with a normal glucose warrants attention. Above 15 is consistent with established insulin resistance in most clinical contexts.
Track your energy pattern for one week without changing anything. Note what time your energy drops, what you ate in the two hours before it dropped, and whether you reach for carbohydrates or caffeine when it happens. This is not a diet intervention yet. It is documentation. The pattern of energy crash timing and the foods that precede it is clinically informative and worth bringing to a physician.
Run a two-week carbohydrate reduction as a diagnostic test. Remove the most refined sources: bread, white rice, pasta, sweetened beverages, and packaged snacks. Do not replace them with anything elaborate. Just remove them. Research by Volek and colleagues across multiple studies found that two to four weeks of refined carbohydrate reduction reduces fasting insulin by 20 to 30 percent in insulin-resistant men. If your afternoon energy pattern, your hunger cycle, and your mental clarity improve meaningfully within two weeks, that response is information about what was driving the symptoms.
Add 30 minutes of moderate aerobic activity on most days and protect your sleep. These two changes are not generic wellness advice in this context. Exercise upregulates GLUT4 transporter expression in skeletal muscle, allowing glucose uptake to occur with less insulin signaling. The HERITAGE Family Study found that 20 weeks of aerobic training improved insulin sensitivity by 10 to 24 percent in men with metabolic syndrome. Sleep matters by a specific mechanism: Spiegel and colleagues, publishing in Sleep in 2005, found that one week of sleep restriction to five hours per night reduced insulin sensitivity by 25 percent. Protecting sleep is a metabolic intervention.

The Measurements That Tell the Real Story

Fasting glucose alone does not capture insulin resistance in its early years. The test that does is fasting insulin. Values above 10 uIU/mL with normal glucose suggest developing resistance. Above 15 is consistent with established resistance in most clinical contexts.

HOMA-IR is calculated from both: fasting insulin in uIU/mL multiplied by fasting glucose in mmol/L, divided by 22.5. A result above 2.0 is generally considered indicative of insulin resistance. Above 3.0 is consistent with metabolic syndrome. Online calculators make this arithmetic immediate once you have both numbers.

The lipid signature to know: a fasting triglyceride above 150 mg/dL combined with HDL below 40 mg/dL is the insulin resistance lipid pattern even when glucose is entirely normal. If those two numbers are present together and the physician has not discussed what they indicate about insulin metabolism, that is a conversation worth initiating.

ApoB and LDL particle number testing, when available, detect the small dense LDL pattern that standard LDL measurement misses. Men with the insulin resistance lipid signature frequently have an elevated ApoB with a normal or borderline LDL, meaning the cardiovascular risk from their lipid pattern is underestimated by the standard panel.

The man who acts on insulin resistance in the compensated phase (before the glucose rises, before beta cell function has partially declined, before the atherogenic lipid pattern has years of runway) is acting during the period when the condition is most reversible. The glucose that is currently normal is the evidence that the window is still open. What he does with the window is the only variable left.

The Signal Check is fifteen questions mapping the male cardiovascular risk pattern, including the physiological domains most commonly missed in standard screenings. It produces a specific starting point for your next clinical conversation.

Start with the gap between how you appear and what your body is doing.

Take the Signal Check

Did this land?

The conversation

Join the men working through this in the open.