9 Weird Things That Can Happen If You Cut Carbs

by Carina Wolff

Diets that cut out of carbs have been around for a while, but carb shunning has seem to have a comeback, likely due to the popularity of trending diets such as Paleo or Keto. However, as tempting as they may sound, there are some dangerous things that can happen to your body if you cut back too drastically on carbs, and with any change in your health, it's important to make sure you do it cautiously and carefully.

"Our body’s preferred source of fuel is carbohydrate, and it is especially what the brain needs to function," says Kimberly Gomer MS, RD, LDN over email. "When you cut out carbohydrates, you always have a diet high in fat. One can’t live on veggies and fish alone, so heavier, fattier, meats, cheese, nuts, etc. come in which negatively impacts heart health, weight, immune function, and cancer risk."

What type of carbs you eat are crucial. You want to stick to whole, unprocessed carbohydrates including fruit and whole grains, and avoid refined carbohydrates such as white rice and white bread. If you're thinking of completing ditching those carbs, you might want to think again. Here are nine surprising and dangerous things that can happen to your body if you dramatically cut back too much on carbs.


Low Blood Sugar


Without consuming adequate and consistent carbohydrates, our blood sugar can drop. "This can actually cause us to seek out more carbohydrates and sugar for instant energy," says Sarah Schlichter, MPH, RDN, LDN over email. Low blood sugar can affect how you feel both mentally and physically.




"You may also feel tired, sluggish and lethargic," says Schlicter. "Protein and fat take longer to absorb and digest, and don't have the same 'instant energy' function as carbohydrates."




"When you cut back on your carbohydrate intake, you are cutting back on your fiber intake, and that can leave you backed up," says Brigitte Zeitlin, MPH, RD, CDN over email. "Constipation can also cause bloating, abdominal cramps, and gas.




"When our blood sugar levels drop too low, we can frequently get headaches," says Zeitlin. "If you are restricting your carb intake, and feeling headachy, this is your body’s way of telling you it needs more carbs."


Bad Breath


Although not exactly dangerous, bad breath as a side effect of a low-carb diet is definitely surprising. When you dramatically cut down or cutout carbohydrates entirely, your body is deprived of glucose and, therefore, it begins breaking down fats for energy. "As this happens, chemicals called ketones (responsible for the name: ketogenic diet) are released, which lead to bad breath and odor," says Rachel Berman, RD over email.


Higher Cholesterol Levels


If you're replacing your carbs with animal protein, you may be in for some trouble. "All animal fats will raise non-HDL, (the dangerous cholesterol) which can lead to heart disease and increased risk of atherosclerosis," says Gomer.


Decrease In Vitamins

In order to get all the nutrients you need, eating a balanced diet is important, and if you're not eating enough carbs, you may be low on certain nutrients. "You may be missing vitamins including the B’s and antioxidants and phytonutrients that come along with the healthy carbohydrates," says Gomer.


Brain Fog


Food affects more than just our bodies — it affects our brain and mental state too. "Our body’s preferred source of fuel is carbohydrate, and it is especially what the brain needs to function," says Gomer. "Hence when you cut out carbohydrates, you feel a brain fog."


Increased Hunger


If you're not eating carbs, you may find that you're still always hungry. "Our bodies are smart and realize that just vegetables and protein will not completely satisfy us," says Schlichter. "We'll often be in search of some sort of carbohydrates to provide the missing link."