Carbohydrates are one of the three macronutrients that our body needs to function properly, alongside proteins and fats. Carbohydrates are the primary source of energy for our body, particularly for our brain, which uses glucose as its primary fuel. Despite this, there are diets that recommend a low-carbohydrate intake, such as the ketogenic diet, which advocates for consuming a high amount of fat and protein while limiting carbohydrates to a minimum. While there are potential benefits to these diets, it is crucial to understand the consequences of a carbohydrate deficiency on the body.

What happens if you eat too few carbohydrates?
When the body does not get enough carbohydrates from the diet, it goes into a state of carbohydrate deficiency, which can lead to a series of physical consequences. In the absence of carbohydrates, the body uses stored fats as its primary energy source, which can result in the production of ketones, a byproduct of the breakdown of fats. While a moderate amount of ketones can be beneficial, excessive production can result in a condition called ketosis, which can be dangerous and lead to a series of health issues.
Physical consequences of carbohydrate deficiency
- Low energy levels: Carbohydrates are the primary source of energy for the body, particularly for the brain. In the absence of carbohydrates, the body may struggle to maintain its energy levels, leading to feelings of fatigue, weakness, and dizziness.
- Muscle loss: Carbohydrates are important for muscle growth and repair, and a lack of carbohydrates in the diet can lead to the breakdown of muscle tissue for energy. This process can result in a loss of strength, decreased physical performance, and reduced metabolic rate.
- Mood changes: Carbohydrates are also essential for the production of serotonin, a neurotransmitter that helps regulate mood. A low-carbohydrate diet can lead to a decrease in serotonin levels, resulting in mood changes, including depression, anxiety, and irritability.
- Digestive issues: Carbohydrates also play a crucial role in digestive health, particularly in the form of dietary fiber. A lack of carbohydrates in the diet can lead to constipation, bloating, and other digestive issues.
- Risk of nutrient deficiencies: Many carbohydrate-rich foods, such as fruits, vegetables, and whole grains, are also rich in essential vitamins and minerals. A low-carbohydrate diet can increase the risk of nutrient deficiencies, particularly if it is not adequately balanced with other nutrient-dense foods.

A study published in the Journal of the International Society of Sports Nutrition found that a low-carbohydrate diet can lead to decreased muscle glycogen stores and a decrease in the body’s ability to use carbohydrates for energy. This study also found that a low-carbohydrate diet can lead to a decrease in physical performance and an increased risk of injury during exercise.
Another study published in the Journal of the American College of Nutrition found that a low-carbohydrate diet can lead to an increase in LDL cholesterol levels, which can increase the risk of heart disease.
A review of studies published in the Journal of the Academy of Nutrition and Dietetics found that low-carbohydrate diets can result in weight loss in the short term. However, the review also found that low-carbohydrate diets can lead to an increased risk of cardiovascular disease and a decreased intake of essential nutrients.
Sources of carbohydrates
While it is essential to limit the intake of processed and refined carbohydrates, it is crucial to consume a sufficient amount of complex carbohydrates, such as whole grains, fruits, and vegetables. These foods provide the body with essential vitamins, minerals, and fiber while helping to maintain steady energy levels throughout the day.
Conclusion
In conclusion, while there may be potential benefits to low-carbohydrate diets, it is crucial to understand the consequences of a carbohydrate deficiency on the body. A carbohydrate deficiency can lead to a range of physical consequences, including low energy levels, muscle loss, mood changes, digestive issues, and an increased risk of nutrient deficiencies. You need to consume an adequate amount of complex carbohydrates, such as whole grains, fruits, and vegetables, to ensure that the body receives the essential nutrients it needs to function properly.
Note that the recommended daily intake of carbohydrates varies depending on factors such as age, gender, weight, and physical activity levels. According to the Dietary Guidelines for Americans, carbohydrates should make up between 45-65% of daily caloric intake.
Also remember that not all carbohydrates are equally beneficial to our health. Processed and refined carbohydrates, such as white bread and sugary drinks, should be limited, while complex carbohydrates, such as whole grains, fruits, and vegetables, should be emphasized in the diet.
In summary, a carbohydrate deficiency can have negative effects on the body, including low energy levels, muscle loss, mood changes, digestive issues, and an increased risk of nutrient deficiencies. You need to consume an adequate amount of complex carbohydrates as part of a balanced diet to ensure that the body receives the essential nutrients it needs to function properly.