Why Your Blood Sugar Reacts Differently to Carbs Than Your Friend’s

We’ve all been told the same thing: carbs spike blood sugar. But here’s the twist—not all carbs affect everyone the same way.

A new study published in Nature Medicine (Wu Y, et.al., 2025) looked at how 55 people responded to common carbohydrate-rich meals like rice, bread, grapes, and potatoes. The results? Huge differences from person to person.

• Some people spiked the most after eating potatoes.
• Others had the highest spike from grapes.
• Rice turned out to be the biggest overall blood sugar booster—especially in Asian participants.

Beans spiked the lowest for everybody.

Why does this happen?

Researchers dug deep using continuous glucose monitors, metabolic testing, and even microbiome analysis. They found that individual factors like insulin resistance, beta cell function, blood pressure, and gut microbes all played a role.

For example:

• Potato-spikers were more insulin resistant and had weaker beta cell function.
• Grape-spikers were more insulin sensitive.
• Bread-spikers tended to have higher blood pressure.

The team also tested “mitigators”—adding fiber, protein, or fat before a carb-heavy meal. These helped reduce blood sugar spikes, but only for people who were insulin-sensitive. For those with insulin resistance, the benefit was much smaller.

What this means for you

• One-size-fits-all nutrition advice doesn’t work. Your body’s response to carbs is unique.
• Tracking your own blood sugar (with tools like a continuous glucose monitor) may be the best way to know which carbs affect you most.
• Pairing carbs with protein or fiber can help—but the effect depends on your metabolic health.
• Adding beans to your meals will keep your blood sugar lower.

Supplement Spotlight: Berberine UltraSorb™

Berberine UltraSorb — enhanced absorption berberine; supports glucose metabolism and cardiometabolic health.

• Ages 18+
• Glucose metabolism support
• Metabolic function support
• Helps support healthy metabolic function
• Promotes healthy insulin receptor function and signaling
• Supports glucose and lipid metabolism
• Provides 550 mg of clinically-studied, enhanced bioavailability berberine phytosome
• Four times more bioavailable than standard berberine
• Made with high-quality, vegan ingredients

Register with Pure Encapsulations to receive a 5% discount and free shipping on all orders:

Bottom line: your friend’s “healthy carb” could be your blood sugar nightmare.

Personalized nutrition—based on your body, not general guidelines—might be the future of preventing diabetes and heart disease.

Reference

Wu Y, Ehlert B, Metwally AA, Perelman D, Park H, Brooks AW, Abbasi F, Michael B, Celli A, Bejikian C, Ayhan E, Lu Y, Lancaster SM, Hornburg D, Ramirez L, Bogumil D, Pollock S, Wong F, Bradley D, Gutjahr G, Rangan ES, Wang T, McGuire L, Venkat Rangan P, Ræder H, Shipony Z, Lipson D, McLaughlin T, Snyder MP. Individual variations in glycemic responses to carbohydrates and underlying metabolic physiology. Nat Med. 2025 Jul;31(7):2232-2243. doi: 10.1038/s41591-025-03719-2. Epub 2025 Jun 4. PMID: 40467897; PMCID: PMC12283382.