When you eat a lot of sugar-loaded simple carbs—like soda, white bread and pasta, or processed snacks—it’s safe to assume you’re probably not getting enough fibre from more complex carb sources, like whole grains, legumes, and fruit.
Those refined carbs cause a rapid surge in blood sugar after your meal, says Myers. Your body tries to correct that spike by producing more insulin, resulting in an energy crash.
But when you eat a fibre-rich meal, your blood sugar increases at a slower, steadier rate. “Fibre, along with protein and fat, helps to slow down digestion, which means sugar is released into our bloodstreams more slowly,” says Alissa Rumsey, M.S., R.D.
“Foods high in fibre help to stabilize our blood sugar and prevent peaks and crashes that can happen with low-fibre, refined carbohydrate-based foods,” she says.
The result? A more controlled and sustained energy boost, says Myers.