A recent exchange between a patient and UCLA Health doctors highlights the impact of both diet and exercise on blood sugar control. The patient, who was asked by her doctor to use a continuous glucose monitor (CGM) for several weeks, noticed improved readings on nights when she and her husband walked after dinner. She believed skipping dessert was responsible, while her husband credited the walking.
The doctors responded that both behaviors are effective in supporting insulin response and maintaining healthy blood sugar levels, though they work through different mechanisms. “The behaviors you and your husband have identified — exercise vs. food choices — are quite different. However, they both bolster the body’s insulin response, which in turn helps maintain optimal blood sugar levels,” the doctors wrote.
They explained that skipping dessert reduces added sugars in the diet, leading to lower blood glucose levels. On the other hand, post-meal walking can immediately moderate blood sugar by allowing muscles to absorb glucose through pathways less dependent on insulin.
Citing research from 2022 conducted in the U.K., the doctors noted that analysis of seven studies found even brief walks after eating—lasting as little as five minutes—improved blood sugar control by making changes more gradual and less extreme. This is significant because sharp spikes in blood sugar are thought to contribute to Type 2 diabetes risk. The positive effects of a post-meal walk were shown to last up to 90 minutes. Even standing briefly after meals offered some benefit, though it was less pronounced than walking.
The CGM device itself is emerging as an important tool for tracking how dietary choices and physical activity affect individual glucose responses over time. According to UCLA Health doctors, these devices provide real-time data that can help people identify patterns related to prediabetes or elevated blood sugar—often called a “silent symptom” because it has no immediate warning signs.
“With the data collected by a CGM, you can see the difference between how a doughnut or an apple affects glucose metabolism, or…the benefits of a post-meal walk,” they said.
In this case, short-term CGM use validated both skipping dessert and taking nightly walks as strategies for better managing blood sugar.
