Why is this effective? Normally, when you dive into something with a high glycemic load, sugar enters your bloodstream and spikes your blood glucose levels fast, leading to a quick zing of energy. However, that high doesn’t last long. “When people’s blood sugar levels go up really quickly, they end up dropping a lot lower than where they started,” says Brigid Titgemeier, a functional medicine RDN. A few hours later, cue brain fog, fatigue, “hanger,” and—surprise—more sugar cravings as your body tells you it needs another boost.
When protein’s in the mix, though, this rebound effect is less pronounced. “Protein helps slow down the absorption of the sugar in your blood,” explains Titgemeier. “This helps prevent the blood sugar ‘highs,’ which then reduces the likelihood of the blood sugar crashes that happen as a result.”
“Protein helps slow down the absorption of the sugar in your blood. This helps prevent the blood sugar ‘highs,’ which then reduces the likelihood of the blood sugar crashes that happen as a result.”
A 2017 study backs this idea up. Researchers from Tufts University found that a piece of white bread paired with tuna (a great source of protein) led to a slower rise in blood sugar than white bread eaten alone or paired with oat cereal (fiber), butter (fat), or rice cereal (more carbohydrates).
Titgemeier’s seen it in her practice, too. “A lot of clients that I work with, especially people who are sensitive to sugar, say that they don’t feel the same impact when they eat protein before they eat sugar,” she says.
While science isn’t exactly clear on why protein modulates the rate that sugar’s absorbed in your blood, it is known that protein is generally digested slowly, which is key for maintaining steady blood sugar. And, in any case, making sure you’re getting enough protein in your diet is a healthy move for other reasons, too. It’s a building block for your body’s tissues (including skeletal muscle), and it also plays an important role in satiety and hormone function, to name just a few of its jobs.
So next time your sweet tooth refuses to be ignored, consider adding in some protein to stave off a post-indulgence crash. Titgemeier’s favorite options are roasted chickpeas and grass-fed beef jerky sticks (as long as they don’t also contain dried fruit, which adds to the sugar content), or go for a hard-boiled egg or a small handful of nuts. They’ll be a match made in heaven for that cookie calling your name—and you’ll thank yourself later.