The Types of Food That Can Hurt Your Sleep

Processed carbs (think: white bread, doughnuts, and cookies) out of the saddle aren't the best food for your overall health.


By Danielle Zickl |

  • According to a new study published in The American Journal of Clinical Nutrition, the more refined—or processed—carbs you have in your diet, the higher your risk is of experiencing insomnia.
  • On the other hand, eating a diet rich in complex carbs lessens your chance of having trouble sleeping.
  • Refined carbs spike your blood sugar, which results in an insulin response that can lower blood sugar to levels low enough to induce secretion of hormones that can wake you from sleep.

When looking at riding food, we tend to rely on fast-acting carbs such as gummies, gels, or energy bars. While these forms of fuel are great to prevent the oh-so-dreadful bonk, filling up on refined or processed carbs (think: white bread, doughnuts, and cookies) out of the saddle isn’t the best for your overall health. Studies have shown it can lead to obesity, type 2 diabetes, and high cholesterol. And now, new research out of Columbia University finds that consuming too many refined carbs can even mess with your sleep.

The study, published in The American Journal of Clinical Nutrition, looked at the food habits of over 50,000 women between the ages of 50 and 79 who participated in the Women’s Health Initiative Observational Study over a four-year period of time (1994 to 1998).

The women filled out an initial survey that included questions about the types of carbs they consumed, all based on the Glycemic Index (GI), which, according to the study, is “considered a measure of the quality of carbohydrate-based foods in the overall diet.” For instance, food like fruits and vegetables are low on the GI scale because they contain minimally-processed, complex carbs. But foods such as bagels and doughnuts are high on the GI scale because they contain highly-processed carbs.

Stick to complex carbs—like whole grains, beans, and vegetables—when preparing your everyday meals.

After a three-year follow-up, researchers found that the more the participants regularly ate foods high on the GI scale (refined carbs—especially those high in sugar), the higher the chances were of experiencing insomnia. Conversely, the more the participants regularly ate foods low on the GI scale (complex carbs—including those rich in fiber), the less they had trouble sleeping.

So what gives? According to James Gangwisch, Ph.D., lead study author and assistant professor of clinical psychiatric social work at Columbia University, it has to do with how the sugars in refined carbs spike your blood sugar.

“Consuming sugars and refined carbs spikes blood sugar, which results in an insulin response that can lower blood sugar to levels low enough to induce secretion of counter-regulatory hormones such as adrenaline and cortisol that can awaken someone from sleep,” he told Bicycling. “Low blood sugar has been shown to produce arousal from sleep and substantially reduce sleep efficiency.”

Gangwisch goes on to say that this study suggests that eating high-GI food could be a risk factor for insomnia, whereas consuming dietary fiber, fruit, and vegetables could help ensure you get proper shuteye.

And while the study only included postmenopausal women, Gangwisch notes that the results would be applicable to younger women and men of all ages, since most everyone experiences a blood sugar spike after eating refined carbs.

So while processed carbs can help fuel your rides, it’s best to stick to your go-to gels or bars on days when you’re doing hard intervals or riding over an hour. Otherwise, stick to complex carbs—like whole grains, beans, and vegetables—when preparing your everyday meals.

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