The Truth About Carbohydrates: Energy, Focus, and Feeling Good

Author: Breanna Mills R.D.

Carbohydrates are one of our three main sources of energy, and they are the preferred energy source of the brain. During digestion, carbohydrates are broken down into glucose and transported throughout the body to provide energy to our cells. Carbohydrates are present in almost all of the foods that we eat and there are three main types of carbohydrates: simple, complex, and fibre. Simple carbohydrates are made of 1-2 molecules joined together and are broken down quicker and provide glucose to our cells faster. Simple carbohydrates can be found in fruit, dairy products, bread, pastas, cereals, etc. Complex carbohydrates are made of multiple molecules joined together and these are broken down more slowly. They are often found in vegetables, whole grains and legumes. Fibre is an undigestible part of carbohydrates and is often found in vegetables, fruits, whole grains, beans and legumes.

Why do we need carbohydrates?

Fuel

Carbohydrates are the main source of fuel for the body and the brain’s preferred fuel source. Carbohydrates help to fuel our muscles, central nervous system and the brain. Our brain can’t store carbohydrates, so it needs a consistent supply in order to function properly. If we don’t eat enough carbohydrates or don’t eat them consistently, this can affect our brain function and make it difficult to concentrate, make decisions, or regulate our emotions.

Protection

Since carbohydrates are the macronutrients that are most easily broken down into glucose, they have a “protein-sparing effect.” If we are eating enough carbohydrates, that means that the body won’t need to break down muscle tissue to provide energy. Then, the protein that we eat can go towards muscle growth and repair.

Digestion

Some carbohydrates can contribute to the growth of healthy bacteria in our intestines, which helps our gastrointestinal health. Fibre is also important to promote regularity with bowel movements and provides bulk to our stool, which makes bowel movements easier to pass.

Mood, Sleep and Appetite

Carbohydrate intake is linked to the release of serotonin in our brain, a neurotransmitter that is important in mood regulation, our sleep cycle and appetite regulation.

How much carbohydrates do I need to eat?

It is recommended that carbohydrates make up about 45-65% of our daily intake. The brain requires at least 120g of carbohydrates per day.

Carbohydrates are often misunderstood and have gotten a bad reputation. Eating enough carbohydrates has a lot of benefits to your overall well-being and helps to provide energy, aid in proper sleep, support brain function and mood regulation.

References

Centre for Clinical Interventions. (2018, February 15). Carbohydrates (myths and facts). Eating Disorders. https://www.cci.health.wa.gov.au/~/media/CCI/Mental-Health-Professionals/Eating-Disorders/Eating-Disorders---Information-Sheets/Eating-Disorders-Information-Sheet---Carbohydrates-Myths-and-Facts.pdf

HealthLink BC. (2025, March 17). Fibre and your health. Fibre and your health | HealthLink BC. https://www.healthlinkbc.ca/healthlinkbc-files/fibre-and-your-health