• Not eating enough carbs can cause physical signs in the body, a dietitian told Insider.
• There is no good reason to reduce or remove carbs from your diet, Nichola Ludlam-Raine said.
• If you don't eat enough carbs you may get brain fog and muscle loss.

Carbohydrates are one of three macronutrients, alongside fat and protein, that make up all our foods. They're found in various quantities in a range of foods, from pasta and bread to oats and bananas.

Cutting out — or cutting down on — carbs is often mistakenly thought to be a way to lose weight, but not only is this a myth, it can negatively impact your health. 

Limiting the amount of highly processed foods like cookies and chips that we eat is usually beneficial. But there is no good reason to reduce or remove carbs from your diet, registered dietitian Nichola Ludlam-Raine told Insider.

Dietary requirements vary from person to person, but the Dietary Guidelines for Americans advises making up half your plate with fruits and vegetables, which are generally primarily made up of carbohydrates.

Physician Dr. Mark Hyman previously told Insider's Gabby Landsverk that the average person should consume up to 75% of their overall food intake (by volume) from carbs. Prioritize getting your carbs from vegetables and fruit rather than sugary or refined carbs, he said.

When you're not eating enough carbs, it can show up in physical signs in the body, Ludlam-Raine said.

"Low-carb diets have been popular for a number of years, even decades now, but reducing your carbohydrate intake can come with a cost," Ludlam-Raine said. 

These side-effects include fatigue, brain fog, and difficulties recovering after exercise.

"Carbohydrates are a primary source of fuel that gives our muscles and brain the energy that it needs to move and think," registered nutritionist Lily Soutter previously told Insider.

4 signs you're not eating enough carbs

1. Lack of energy

Carbs are the body's main source of fuel, so if you reduce your carb intake significantly, you'll likely notice a depletion of your energy levels, too, Ludlam-Raine said.

"Our body can use other sources of fuel (such as fat), although carbohydrates are able to provide a more rapid source of energy to enable us to function optimally, both cognitively and physically," she said.

2. Brain fog

The brain requires glucose, which is broken down from carbs, to function optimally. So when you haven't consumed enough carbs, you may find yourself in a bad mood and struggle to concentrate, Ludlam-Raine said.

"Consuming carbs alongside protein helps to support the production of tryptophan which is then converted into serotonin, also known as the happy hormone," she said, referring to the essential amino acid needed to produce and maintain the proteins in our bodies.

Ludlam-Raine recommends getting your carbs mostly from wholegrains, fruits, and vegetables, as these provide fiber and essential nutrients to support overall health and mental wellbeing.

3. Less energy for workouts

The body stores carbohydrates as glycogen in the liver and muscles. This is used for energy and thus beneficial for exercise, whether that's running, cycling, or gym workouts, Ludlam-Raine said.

Eating enough carbs is particularly important for people who do high intensity workouts like HIIT (high intensity interval training) or CrossFit, sports nutrition coach Dr. Mike Molloy previously told Insider.

If you haven't consumed enough carbs, your performance will hit a ceiling and you may suffer from muscle loss and "exercise flu" — this is "a pretty nasty place" where you feel totally out of it, your body aches, your head hurts, and you just want to lay on the ground, Molloy said.

4. Difficulty recovering from workouts

Carbs are not only beneficial for fueling exercise, but they aid recovery from workouts too.

"After we exercise, our body needs to replenish its glycogen stores that have been depleted during a workout, and therefore it's recommended to consume carbohydrates alongside protein to support recovery and enable you to feel at your best before your next workout," Ludlam-Raine said. 

If your body doesn't recover efficiently, you may have muscle pain for longer after your workout, have less energy when you next hit the gym, and make slower progress.