Insulin resistance is being talked about more as GLP-1 medications become part of the mainstream conversation around blood sugar and weight. At its most basic, it’s what happens when your cells stop responding to insulin as they should, allowing sugar to build up in the bloodstream. For many people, the early signs show up long before any diagnosis or prescription—often in small, everyday ways that are easy to overlook.
Ahead, experts break down how insulin resistance can show up in everyday life, often before it’s flagged in bloodwork.
Featured Experts
- Ayla Barmmer, MS, RD, LDN is a registered dietitian in Concord, MA and the founder of FullWell
- Felice Ramallo, MSCN, RDN, LD/CDN is a registered dietitian nutritionist and lead dietitian at Allara Health
Early Patterns Experts Notice First
One pattern Ayla Barmmer, MS, RD, LDN sees “over and over again” in her clinical practice is what she calls the “doing everything right but nothing’s working” phase. It shows up in women who are eating well and exercising consistently, yet still can’t lose weight—or are gaining weight despite no real changes to their routine. That kind of “metabolic stuckness,” she says, “is often a sign” of insulin resistance.
How you move throughout the day matters just as much as how often you work out. Barmmer notes that someone can crush a morning workout and still struggle metabolically if the rest of the day is spent sitting. Felice Ramallo, MSCN, RDN, LD/CDN sees the same pattern in lifestyles built around long commutes, desk-heavy days and frequent takeout, which “often contribute to insulin resistance,” she says.
Sleep and stress tend to layer on as well. “If you’re consistently getting less than seven hours, or your sleep quality is poor, that alone can drive insulin resistance,” Barmmer explains. Chronic stress plays a role, too. “Cortisol and insulin have an intimate relationship, and when cortisol stays elevated, insulin sensitivity suffers.”
Hunger, Cravings and Energy Red Flags
For many people, insulin resistance becomes harder to ignore when it starts affecting appetite and energy. “One of the most noticeable signs of insulin resistance are significant or increased cravings and appetite,” says Ramallo. “This often comes along with out of control or unintentional weight gain. Eating more calories than your body needs contributes to insulin resistance. This is made worse if there are a lot of added sugars and processed foods in the diet.”
Barmmer sees a familiar pattern play out: you eat, feel okay for a short while, then crash. That drop can bring brain fog, irritability and a strong pull toward carbs or something sweet. “That’s your blood sugar on a rollercoaster, and it’s a hallmark of insulin resistance,” she says. And there’s a physiological reason those cravings feel so intense. “Even though there’s plenty of sugar in your bloodstream, your cells are essentially starving,” she explains. “Your brain interprets this as ‘we need more fuel,’ and sends out craving signals.”
Hunger cues can shift in subtler ways, too—feeling hungry again shortly after meals, never quite feeling satisfied or having little appetite early in the day only to feel out of control later on. Fatigue often follows. Ramallo notes that insulin resistance can lead to “higher background levels of insulin,” which many people experience as constant tiredness, low motivation or the familiar 2–3 p.m. slump Barmmer sees regularly in practice.
Skin and Body Symptoms to Watch For
Some signs of insulin resistance are easier to see than feel. One of the most well-known, Barmmer says, is acanthosis nigricans, “which presents as darkened, velvety patches of skin, typically in the folds of the neck, armpits or groin.” It’s a clue she says shouldn’t be brushed off, noting that “this is a visible marker of insulin resistance.”
“Skin tags are another one,” she adds. “They’re so common that people think of them as just a normal part of aging, but clusters of skin tags, especially around the neck and underarms, are associated with insulin resistance.” Ramallo notes that acne, increased facial hair (hirsutism) and ingrown hairs can also show up as insulin resistance disrupts hormone balance.
Body changes can offer clues, too. Barmmer pays close attention to central adiposity—when weight tends to collect around the midsection rather than distribute evenly. Ramallo adds that “less muscle and more fat accumulation,” especially at the waist, is a common pattern, with a measurement over 35 inches considered a potential red flag.
And finally, Brammer points to menstrual changes as a common but often overlooked clue. Irregular or lengthening cycles can signal that insulin resistance is affecting ovarian function, whether someone is dealing with PCOS or navigating perimenopause.
The Takeaway
If any of these signs sound familiar, they’re worth discussing with a doctor, who can help determine what’s actually going on—and whether lifestyle changes, further testing or treatments such as GLP-1 medications might be suitable for you.
