4 physical signs you need to eat more carbs, from brain fog to exercise flu

• Not eating enough carbs can have physical effects, a dietitian told Insider.
• There is no good reason to reduce or remove carbs from your diet, Nichola Ludlam-Raine said.

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

Cutting out or cutting down on carbs is often thought to be a way to lose weight. But not only is this a myth — it can harm your health.

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

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

Dr. Mark Hyman previously told Insider's Gabby Landsverk that carbs should make up to 75% of the average person's overall food intake by volume. He recommended getting your carbs from vegetables and fruits rather than sugary or refined sources.

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

Ludlam-Raine said that physical signs — including fatigue, brain fog, and difficulties recovering after exercise — can show you're not eating enough carbs.

"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.

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.

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

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 working out at the gym, Ludlam-Raine said.

Mike Molloy, a sports-nutrition coach, previously told Insider that eating enough carbs is particularly important for people who do high-intensity workouts like high-intensity interval training, or HIIT, or CrossFit.

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

4. Difficulty recovering from workouts

Not only are carbs beneficial for fueling exercise, but they aid recovery from workouts.

"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.