8 Things That Happen When You Stop Eating Bread

The good, the bad, and the constipation 

The low-carb craze is going strong. Bread is out. Pasta is overrated. And dieters are experimenting with how low their carb intake can go. But grains are anything but all the same. So whether you are cutting out refined grains, whole grains, or carbs in general, the effects can vary widely. Here’s a look at the wide array of things that happen when you ditch the bread bags:

• When you reduce your carb intake, the first thing you notice is how quickly, even magically, the weight falls off. But it’s not fat you’re losing. It’s water. “When carbs are stored in the body in the form of glycogen, each gram of carbohydrate stores three to four times its weight in water,“ says dietitian and strength coach Marie Spano, R.D., C.S.C.S. So as soon as you cut carbs and start using your glycogen stores, you’ll lose a good amount of water weight. 

• "Carbs are the brain’s main source of energy,” says Spano. “When a person cuts down on carbs, the brain is running on fumes, especially as glycogen stores get low and become depleted.” Eventually, once all that glycogen is gone, your body breaks down fat and runs off of little carbon fragments called ketones. The result: bad breath, dry mouth, tiredness, weakness, dizziness, insomnia, nausea, and brain fog. Basically, you feel like you have the flu. Eventually, your body adapts to running on ketones so you don’t feel so bad, but they are still aren’t your body’s preferred fuel source, says Spano.

• Refined carbohydrates are infamous for sending your blood-sugar levels through the roof, only for them to crash back down again. And recent research published in the American Journal of Clinical Nutrition suggests that the rollercoaster ride activates addiction centers in the brain, leading to subsequent cravings. Opting for fiber-rich whole grains, though, can keep blood-sugar levels from plummeting to prevent cravings, says nutritionist Alex Caspero, R.D., owner of Delicious Knowledge. 

• The type of grains you cut makes a big difference here. For instance, a 2014 study published in PLOS ONE found that refined carbohydrates drive up the body’s levels of a fatty acid (called palmitoleic acid) to raise the risk of heart disease and type 2 diabetes. Meanwhile, according to the American Heart Association, whole grains can improve blood-cholesterol levels and lower risk of heart disease, stroke, obesity, and type 2 diabetes. The choice is clear. 

• Whole grains are a great source of iron, magnesium, and B vitamins, all of which are critical in maintaining energy levels, says Spano, who notes that many people are already deficient in magnesium. Plus, since carbs are your body’s preferred fuel source, all of your cells slow down without a healthy supply, says Caspero.

• Whole-grain intake is a major player in how much fiber you get, according to a recent Nutrition Research study that found that 92 percent of U.S. adults don’t get enough of the grains. Fiber, the indigestible part of plants, like grains, not only helps stabilize blood-sugar levels, reduce the risk of obesity, and chronic diseases, but keeps your bathroom habits regular, says Spano. 

• And not just because you’re eating all of your sandwiches as lettuce wraps. Carbs—whether they are whole or refined—increase the brain’s levels of the feel-good neurotransmitter serotonin, says Caspero. So when you cut healthy carbs like whole grains, your mental health goes right along with it.

• “Carbohydrates are the body’s primary source of energy for fueling all exercise, including both endurance and resistance training,” says Spano. “Cut carbs, and your energy will drop. Decrease your levels of your body’s stored carbohydrates, and your ability to produce force and power will decrease.” And the suckier your workouts, the suckier your results.