Carbohydrates have been battling a bad reputation for many years. The fancy name for sugars, starches and fibres, they have been misunderstood and demonised with many people believing they cause weight gain and gut issues.
However, carbohydrates are simply misunderstood. They are the primary source of energy for the body and an absolute essential in everyone’s diet. It’s important to know which ones are best for you, your health, lifestyle and training needs.
What are carbohydrates?
Carbohydrates are saccharides – a group that includes sugars, starch, and cellulose (fibre).
They are one of the three macronutrients (the others are protein and fat) that the body needs to function, grow, repair and survive.
What do carbohydrates do?
The primary role of dietary carbohydrate is the provision of energy to cells, particularly the brain that requires glucose for its metabolism.
The digestive system breaks down the carbohydrates in foods and drinks into simple sugars, mainly glucose. This simple sugar is then carried to each cell through the bloodstream. Once inside a cell, the glucose is ‘burned’ along with oxygen to produce energy.
The body converts excess glucose from food into glycogen. Glycogen is stored in the muscles for energy at a later time. If the muscles max out their storage capacity, glycogen will be converted to fat.
If carbohydrates are not present, your body will utilise fat and protein for energy, which is an inefficient energy source for the brain and for runners and athletes.
What foods contain carbohydrates?
All fruits, vegetables, grains, legumes and milk products contain carbohydrates; but they are not all created equal.
Without getting bogged down in the detail of the unique chemical structure of the different saccharide groups it’s often easier to understand that there are two main types:
- Simple carbohydrates
- Complex carbohydrates
There are pros and cons to both depending on your unique energy needs.
Simple carbohydrates are broken down into sugar and converted to energy quickly, causing a spike in blood glucose and insulin levels.
SIMPLE carbohydrates include:
- Most refined sugar products (cakes, biscuits, confectionary, soft drink)
- Dried fruit
- Fruit juice
- White potatoes
- White bread
- White rice
For maintaining good general health, dieticians recommend avoiding simple carbohydrates. They don’t deliver consistent energy and are stripped of many micronutrients, vitamins, minerals and phytochemicals. A serving of simple carbohydrates will often leave you hungry, unsatisfied and looking for another meal soon after; leading to overeating and weight gain.
However, if you’re completing a long run and need a quick boost of energy before a big hill climb, simple sugars may be perfect. They’re absorbed quickly and the low fibre content also reduces the chances of any #2 toilet trips mid-race. It’s the reason why you see lots of sugared energy drinks, watermelon and fruit buns at trail run checkpoints.
Simple carbohydrates also play a role during the first 24 hours of recovery after an event to rapidly replenish muscle fuel stores (glycogen).
Complex carbohydrates are more slowly digested, absorbed and metabolised and cause a lower and slower rise in blood glucose and, therefore usually, insulin levels.
Outside of your intense training and racing, complex carbohydrates should make up most of your diet. They deliver consistent energy and are full of micronutrients, vitamins, minerals, phytochemicals and digestive fibre. Complex carbohydrates will also help with growth and repair of the body.
COMPLEX carbohydrates include:
- Sweet potatoes
- Rye bread
- Brown rice
- Wholewheat pasta
- Legumes, such as black beans, chickpeas, lentils
- Loads of coloured fresh fruits and vegetables!
How many carbohydrates do I need each day?
The dietary guidelines recommend that carbs provide 45–65% of your daily intake. You’ll need more if you have a heavy schedule of training and racing.
Should you load up on carbs before a run?
Eating lots of carbohydrate-heavy foods leading up to a race stocks your muscles and liver with glycogen. But it’s only necessary if you’re exercising intensely and continuously for 90 minutes or more and you’re confident that the glycogen will be used.
Choose complex carbohydrates to ensure you’re getting the full benefit of vitamins and minerals that are often depleted with intense exercise.
But what about the weight gain and gut issues?
If you’re overeating, it doesn’t matter if it’s carbohydrate, protein or fat, there’s a chance you’ll put on weight. If you’re concerned about your weight, pay more attention to your serving sizes and focus on eating complex carbohydrates.
Complex carbohydrates will also help with good gut health. The increase in fibre feeds the good bacteria in the gut.
So don’t be scared of carbs! They’re absolutely essential to the diet and once you know the difference between simple and complex and what your unique training and lifestyle goals are you’ll start to make peace with plants.
Nutrient Reference values: https://www.nrv.gov.au/nutrients/carbohydrate