So what exactly are carbohydrates (carbs) ?
Carbohydrates are a macro nutrient that provides energy and other health benefits. Carbohydrates are present in all fruit and vegetables, breads and grain products, and sugar and sugary foods.
It is best to choose carbohydrate-rich foods that are healthy and full of dietary fibre.
We need carbohydrates to balance blood sugar levels and as an energy source.
Our bodies are designed to be fuelled with carbohydrates and as such we need them for our energy needs.
In the absence of carbohydrates our body will convert dietary protein to glucose via a process called gluconeogenesis, and as a flow on effect if our bodies utilise all dietary protein for energy sources the catabolism/breakdown of muscle can occur.
Eating carbs after a certain time of day is NOT a bad thing. Eating carbs of an evening won’t make you fat.
If we eat carbs in excess of our energy needs and a calorie surplus occurs, we can store excess calories as bodyfat
Each gram of carbohydrates we consume contains 4 calories. As an example, 1 average sized banana contains approximately 25 grams of carbs or 100 calories.
Types of carbohydrates
Sugars, starches, and some types of dietary fibre are carbohydrates. Sugars include:
- glucose — in fruit, honey, and some vegetables
- fructose — in fruit and honey
- sucrose — from sugar cane
- lactose — in all types of milk including breast milk
- maltose — in malted grains
Starches are also known as complex carbohydrates. Starches can be found in:
- legumes/beans/peas - Chickpeas, black beans, green peas, lima beans, kidney beans, black eyed peas, navy beans, baked beans, peanuts (yes peanuts are a legume) etc
- nuts – almonds, macadamias, Brazil, cashews etc (peanuts are technically a legume)
- potatoes – white, sweet etc
- rice – white, brown, black, basmati, jasmine etc
- pasta
Starches are also found in cereal and grain products such:
- oatmeal – rolled oats, quick oats etc
- breakfast cereals – boxed cereal etc
- flour – white, self-raising, wholemeal etc
- polenta/corn grits
- couscous
- burghul (cracked wheat)
- quinoa
- buckwheat/buccinas
- seeds such as sunflower, chia, hemp, pumpkin, watermelon, flaxseed, sesame
Dietary fibre is found in many different plant foods including:
- vegetables
- wholegrain foods
- legumes/beans
- fruits
- nuts
- seeds
How are carbohydrates digested?
Carbohydrates are digested in the small intestine. They are broken down into simple (single) sugars such as glucose and fructose.
These sugars are absorbed into the bloodstream and can be used for energy. Some sugar is converted to glycogen and stored intramuscularly and within the liver.
Glycogen is also stored in muscles for muscle activity. Carbohydrates not used for energy or glycogen storage are converted to fat.
Glycaemic index
The speed at which the carbohydrates in a food are digested to glucose is called the food’s glycaemic index (GI) value.
Low GI foods are broken down slowly. They cause slow rising of blood sugar levels. The glucose, or energy, from their carbohydrates is released into the blood over several hours. Low GI foods prolong digestion due to their slow break down and may help with you to feel fuller for longer.
High GI foods are digested rapidly and give you a rapid blood glucose spike. In most instances (apart from post workout) Slow digestion is better than fast digestion, so low GI foods are generally better than high GI foods. This is important if you have diabetes — it helps keeps your blood glucose levels stable.
It’s important to look at the overall nutritional value and carbohydrate content of a food item, not just the GI. Junk food with a low GI is still junk food.
A calorie is not a calorie.
50 grams of carbs from a doughnut is not equivalent to 50 grams of carbs from a high-quality source such as rice, sweet potato or most types of fruit for instance.
Bear this is mind when utilising flexible dieting methods.