The Importance of Having a Balanced Diet for Sport

The Importance of Having a Balanced Diet for Sport

A nutritious diet is important for everybody, but athletes especially need the nourishment and fuel provided by healthy foods. So many of the products that line the supermarket shelves these days are severely lacking in real nutrients, and are often processed so much that they can barely be recognized as food. These so-called foods are lacking in nourishment even for couch potato types, so sportspeople can’t hope to get the fuel they need from the typical processed food diet. A diet lacking in vitamins, minerals and other important nutrients will result in a sluggish body which soon becomes fatigued. For peak sports performance, you need to look beyond your sessions in the gym and start thinking about the food you put into your body.

All food is basically made up of three molecular structures, which you are probably already familiar with: carbohydrates, protein and fat. But how do they work in your body and what role do they play in sports performance?


Your body breaks these down into sugar (glucose) which is used to fuel your energy. Carbs are converted into glycogen and stored in the liver and muscle tissue. They are our body’s main source of energy so a diet which is low in carbohydrates can quickly lead to fatigue as there are insufficient stores of glycogen for the body to convert into energy. In such a case, the body will start to break down muscle and fat to use as energy.

There are two types of carbohydrates: simple and complex. Simple carbs are generally processed very quickly in the body resulting in a quick spike of energy which soon fades. Some athletes find these useful to consume during a sporting event for a quick boost when they start to feel fatigued, but one should be careful about consuming simple carbs too often as the benefits are short-lived and they are often present in refined food products which lack nutrition. Avoid refined sugar and white flour, in favour of whole foods like milk or honey which also contain beneficial micronutrients.

Complex carbohydrates are broken down into energy over a longer time period, resulting in a sustained energy release over several hours. While simple carbs are a quick cheat for an energy boost, most of your overall energy should come from complex carbs, which are commonly found in whole grains and beans. Fruit is also a healthy source of carbohydrates.

The Glycaemic Index

A useful tool to measure how much energy you can expect from a given food is the Glycaemic Index (GI) which measures how quickly blood sugar levels are affected. A high GI food is released as blood sugar very quickly but the energy also gets used up very quickly and you will become fatigued fairly quickly. If you need to eat during your workout, or just after finishing, these may help you keep going for a while. Low GI foods should be eaten before sports and as part of your daily eating habits for more sustained energy release.


People often think that athletes need to take a lot of protein supplements in order to ‘bulk up’ and support their muscle growth. While it is true that protein contributes to tissue growth and regeneration, dietary protein is usually more than enough even for athletes’ needs.

The most widely recognized sources of dietary protein are meat, fish, eggs and dairy foods. Not many people realize that protein is also found is vegetables, whole grains (which are often a mix of carbohydrate and proteins) and, seeds, nuts and legumes.


Demonized for decades as unhealthy, scientists are now coming to recognize the essential role fats play in our diet. When you run out of glucose from carbohydrates, your body turns to fat as the next energy source. Some scientists advocate a low-carb diet, claiming that it’s possible to train your body to use fat as its primary energy source, but most conventional nutritionists still advocate for dietary carbohydrates as the main source of energy, especially for athletes. It’s certainly worth considering which option is right for you and your individual body.

Foods like nuts, avocadoes, seeds and oily fish are high in fat and other nutrients.


Drinking enough fluid during sport is essential, as dehydration can lead to fatigue and even more serious health risks. Water is generally the best option, although some athletes may choose sports drinks with electrolytes. Sports drinks can be highly processed and full of sugar or artificial sweeteners which are not a healthy long term option. If you need the occasional kicks of energy they can provide hydration and a blood-sugar boost to keep you going for a little while but should be used with sparingly and with caution.

Even slight dehydration can affect your physical performance, so keep on top of your hydration not only during sport but as a general lifestyle rule.

What should sports people eat?

Athletes may require more calories that the average person to replenish the fuel they use up during the day, depending on the sport and the amount of training. Even if you just want to start doing a bit of recreational exercise, you may feel hungrier that you otherwise would have. It’s important to give your body the nourishment it needs, but it’s always better to consume healthy, natural foods rather than unhealthy ‘empty’ calories.

Your choice of food may be influenced by your particular sport. Endurance runners might want to focus on low GI carbohydrates for sustained energy release, while weightlifters might need fewer carbs and more protein to help build healthy muscle tissue.

Whether you’re an athlete, a sports enthusiast or just enjoy casual exercise, diet plays a huge role in your physical health. While athletes may want to pay extra attention to the chemical reactions going in their bodies, a healthy diet isn’t just about molecules and blood glucose levels. It’s easy to become obsessed with the ratio of nutrients in every food you eat, but don’t get carried away with food science. Eat a wide range of whole foods and you will almost certainly get the nutrition you need for peak physical performance.