Seventeen years ago, when I was pregnant with my daughter, I was diagnosed with gestational diabetes. I assumed it would go away after delivery, as it does for many people. But it didn’t. Today, like about 1 in 3 American adults, I live with prediabetes, marked by elevated HbA1c—a quiet signal that my blood sugar regulation is off. What’s more troubling is that most people with prediabetes don’t know they have it. And the consequences aren’t trivial: about 70% of people with prediabetes eventually develop type 2 diabetes, and even before that, the spikes and swings in blood sugar can fuel inflammation, high blood pressure, cardiovascular disease, kidney damage, and more. Here’s how a recent Nature Medicine paper frames one of the challenges in its opening sentences:
Elevated postprandial glycemic responses (PPGRs) are associated with type 2 diabetes and cardiovascular disease. PPGRs to the same foods have been shown to vary between individuals, but systematic characterization of the underlying physiologic and molecular basis is lacking.
That is: we’ve known for a while that some foods spike blood sugar more than others, but we haven’t fully understood why the same food can spike one person’s glucose dramatically, while barely nudging another’s. This study took a rigorous look at that mystery. The researchers gave 55 people seven different carbohydrate-rich meals—rice, bread, potatoes, pasta, beans, grapes, and berries—and then tracked their glucose levels. They also performed an in-depth analysis of their metabolic health.
As expected, blood sugar responses to the same foods varied hugely between individuals. For example, rice produced the biggest spike in most people, but others spiked more with potatoes, bread, or even grapes. But these response patterns weren’t random—they reflected underlying physiology. People who spiked most after potatoes were often insulin resistant and had weaker beta cell function, whereas “grape-spikers” were generally more metabolically healthy. Another key insight: “mitigators” like fiber, protein, or fat—when consumed just 10 minutes before a meal—could blunt glucose spikes, but only in people with good metabolic health. For insulin-resistant individuals like me, these strategies were less effective.
The takeaway is both sobering and empowering: glycemic responses are personal, shaped by your unique metabolic profile. Blood sugar is easy to monitor, and can expose dysfunction that traditional labs might miss. Many of us are trying to be pro-active about health – and this kind of personalized insight could be a key to staying on the right side of the tipping point.
Individual variations in glycemic responses to carbohydrates and underlying metabolic physiology
In Nature Medicine, 4 June 2025
From the groups of Tracey McLaughlin at Michael P. Snyder at the Stanford Diabetes Research Center of Stanford University.
Snippet by Angela Andersen
Image credit: Figure 1a from Wu et al. cited above (CC BY-NC-ND)