Skip to content

8 Side Effects of Eating Too Many Carbs

If you're experiencing any of these signs, you may need to start cutting back.

Unless you really like math, you may find that tallying up how many carbs you eat in a day isn't a whole lotta fun. For the record, the Food and Drug Administration's (FDA) guidelines recommend that carbohydrates make up 45 to 65% of your total daily calories. If you take in, say, 2,000 calories a day, that would be between 900 and 1,300 calories from carbs or around 225 to 325 grams. And if you're not careful, you could be eating too many carbs in one day.

For a more visceral idea if you are overdoing the bread, rice, pasta, chips, and Mountain Dew, see if you notice any of these common side effects of eating too many carbs below. That knowledge may nudge you to focus on consuming the much healthier variety of complex carbs. Read on, and for more healthy eating tips, check out our list of 21 Best Healthy Cooking Hacks of All Time.

Fatigue

fatigue
Shutterstock

Chronic fatigue, or even feeling tired after consuming simple carbohydrates, could be a side effect of habitually eating too many carbs, according to the National Sleep Foundation. While eating high-carb foods can temporarily raise blood sugar levels and energize your body and brain for action, the rise is often followed by a rapid decrease in blood sugar, which reduces the activity of certain neurons involved in the sleep/wake cycle among other things and saps your energy, suggests a study in Frontiers in Endocrinology. What's more, when you eat too many carbs during the day, you may find your sleep disrupted, making you feel exhausted the following day. For reference, Here's How Many Carbs You Can Eat a Day to Lose Weight.

Weight gain

stepping on scale
Shutterstock

Eating too many calorie-dense carbohydrates, like chips, baked goods, pizza, sugary beverages, cocktails, and crackers, can obviously put weight on you. But there's more going on here than calorie overload. To understand how, you have to know how insulin works.

When you eat too many processed carbohydrates, many people get an insulin spike—the pancreas floods the body with the hormone to help the glucose enter your body's cells, which lowers glucose levels in your bloodstream. But when your cells get more glucose than they need because you've eaten way too many carbs, the body converts the excess glucose into fat.

In a study in the journal Clinical Chemistry, researchers at Harvard Medical School analyzed data on more than 140,000 people who experience high insulin after eating processed carbohydrates and found a strong association with higher body mass. "It appears that a lifetime of high glucose-stimulated insulin secretion…is obesogenic," wrote the study's lead scientist David Ludwig, MD, an endocrinologist, and professor at Harvard Medical School.

Here are 19 Surprising Foods With More Carbs Than a Bowl of Pasta.

Weight loss

Woman taking mirror selfie at a gym showing off her weight loss
Shutterstock

Yes, we just presented evidence that high carb intake can lead to weight gain. But it all depends upon the type of carbohydrates regularly consumed. A study in the journal Nutrients found that a diet overwhelmingly rich in plant-based carbohydrates can reduce body weight, body fat, and improve insulin function.

"Fad diets often lead people to fear carbohydrates. But the research continues to show that healthy carbohydrates–from fruits, vegetables, beans, and whole grains—are the healthiest fuel for our bodies," says lead study author Hana Kahleova, M.D., Ph.D., director of clinical research for the Physicians Committee for Responsible Medicine.

Here are 16 Simple Ways To Cut Back On Carbs.

Getting gassy

gassy
Shutterstock

Eating meals rich in carbohydrates makes your body retain water, which can make you feel bloated. Many types of carbs—from sugary processed foods to fruits and vegetables to carbonated beverages like sodas—can generate abdominal gas. The most gas-producing foods are short-chain carbohydrates called FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) foods. You can find a complete list of FODMAPs from the National Institute of Diabetes and Digestive and Kidney Diseases website.

Want a flat belly? Here are 9 Foods To Avoid if You Want to Lose Belly Fat, Say Experts.

Craving more carbs

pasta eating
Shutterstock

Eating lots of sugary carbohydrates can activate parts of the brain in ways similar to patterns involved in substance dependence like drug and alcohol addiction, according to research in Archives of General Psychiatry. Consuming carbs triggers the release of dopamine, a pleasure hormone. Researchers have measured elevated activation of this reward circuity in response to carbohydrate cues, as well as the deactivation of areas of the brain that inhibit overeating.

Cavities

cavities
Shutterstock

You've known what jawbreakers, gummi bears, and Jolly Ranchers will do to your teeth since you were four, but were you aware that your adult obsession with fries and pizza can give you cavities, too? Carbohydrates, especially starchy ones like chips, pasta, and bread, are broken down by saliva into simple sugars, according to The American Journal of Clinical Nutrition. The bacteria in your mouth feed on these sugars and produce acids that affect plaque pH, cause tooth demineralization, and trigger decay. So, listen to your childhood dentist: brush after every meal, especially those high in carbs.

For more healthy eating tips, sign up for our newsletter.

A sluggish brain

Man thinking at a computer
Shutterstock

Glucose, from carbohydrates, is the brain's primary source of energy. But make a habit of eating too many carbs and that brain fuel could backfire. In a study funded by the National Institutes of Aging, Mayo Clinic researchers tracked 1,230 people age 70 and older for about four years and found that those who eat diets high in carbohydrates, including diets high in sugar, have nearly four times the risk of developing mild cognitive impairment.

"A high carbohydrate intake could be bad for you because carbohydrates impact your glucose and insulin metabolism," says lead study author Rosebud Roberts, a Mayo Clinic epidemiologist. "Sugar fuels the brain—so moderate intake is good. However, high levels of sugar may actually prevent the brain from using the sugar—similar to what we see with type 2 diabetes."

Acne

Woman with problem skin
Shutterstock

Self-reported dietary studies suggest that young people who eat more sugary foods, especially those processed carbohydrates with added sugars as well as milk and saturated fats, may aggravate acne. Researchers reporting in the Journal of the Academy of Nutrition and Dietetics asked 248 (115 male, 133 female) participants age 18 to 25 to complete questionnaires measuring reported acne severity and dietary habits. They found that, compared to participants with mild acne, those with moderate to severe acne reported greater consumption of added sugars, milk, and saturated fats. 52% of all participants blamed their diets for aggravating breakouts.

So ditch those processed carbs and enjoy these The 9 Best Complex Carbs for Weight Loss instead.

Jeff Csatari
Jeff Csatari, a contributing writer for Eat This, Not That!, is responsible for editing Galvanized Media books and magazines and for advising journalism students through the Zinczenko New Media Center at Moravian University in Bethlehem, PA. Read more about Jeff
Filed Under