Signs & Symptoms of Not Enough Carbohydrates

Skimping on carbohydrates can cause low energy, constipation, headaches and nausea.


Carbohydrates are often viewed as a cause of weight gain and obesity-related diseases. As a result, many people trying to lose weight shun carbohydrates; however, your body needs carbohydrates to function properly. The 2010 Dietary Guidelines for Americans recommend that carbohydrates make up 45 to 65 percent of total daily calories, which means you'd need to consume between 225 and 325 grams of carbohydrates a day if you normally consume 2,000 calories, according to Signs and symptoms that you're not consuming enough carbs include everything from fatigue to constipation to headaches, nausea and even bad breath.

Lack of Energy

According to the University of Maryland Medical Center, the main role of carbohydrates is to provide your body, particularly your brain and nervous system, with energy. An enzyme secreted by your body converts carbohydrates into glucose, or blood sugar, which is the fuel your body needs for energy. Some of this is used for immediate fuel, and the leftover glucose is stored in your liver, muscles and cells for later use. If you don't consume enough carbohydrates, you'll lack energy, which can make you feel tired, weak and unable to think clearly.


Healthy carbohydrates include whole-grains, vegetables, fruits, beans and nuts. If you don't consume enough of these plant-based carbohydrates, your diet may be low in fiber, which can lead to constipation, according to PubHealth. Constipation is defined as having a bowel movement less than three times a week. Other signs of constipation include hard stools and difficult passing stools, which can cause discomfort when going to the bathroom. Consuming enough complex carbohydrates, such as whole-grain breads, pastas and cereal, will aid your digestive health by helping waste move through your body and reducing the risk of constipation.

Nutritional Deficiencies

According to the Weight-Control Information Network, if you skimp on carbohydrates you could miss out on key nutrients needed for good health, leaving you vulnerable to minor illnesses and serious diseases. For example, citrus fruits, broccoli and tomatoes are good sources of vitamin C, while carrots, sweet potatoes and apricots are rich in vitamin A; beans are high in folate and whole-grain carbs contain a wealth of minerals and B vitamins. Vitamin C helps support immunity, vitamin A is important for eye health and folate plays a vital role in many of your body's functions and may help prevent heart disease. Signs of poor nutrition may not be obvious immediately, but they can a toll on your health over time.

Nausea, Headache and Bad Breath

Drastically restricting carbohydrates to less than 20 grams a day can result in ketosis, which occurs when your body doesn't have enough glucose for energy, according to When you deprive yourself of energy-providing glucose, your body breaks down stored fat. These partially broken-down fats trigger ketosis. Signs and symptoms of ketosis include nausea, headache and bad breath, as well as mental fatigue. Moreover, ketosis can cause your body to produce high levels of uric acid, which can be a risk factor for painful swelling of the joints and kidney stones, reports the Weight-Control Information Network.

About the Author


Photo Credits

  • Brand X Pictures/Brand X Pictures/Getty Images
Suggest a Correction