Blood sugar is essentially a measurement of the amount of glucose in the body. Glucose is what the brain uses for fuel and is created when the food (carbohydrates) we eat is broken down and released through the bloodstream to the cells for energy.

The brain needs glucose to function. Without it, our cognitive abilities would suffer considerably. Congruently, the correct dose of glucose can make all the difference when it comes to performing well. As there are no energy deposits in the brain like in the muscles, it relies on a continuous supply of glucose to maintain stable blood sugar levels and thus operate efficiently, at a stable pace. 

This knowledge can be quite powerful for gaming enthusiasts, as eating a diet aimed at creating a stable blood sugar level is a game-changer if you’re wanting to perform at a high cognitive level, consistently, for long periods. For example, eating carbohydrate-heavy meals in between sessions will cause large fluctuations in one's blood sugar levels, which will be mirrored by large fluctuations in brain performance, including cognitive abilities and emotional state. Prioritising three larger meals a day combined with small snacks if hungry, will offer the energy your brain needs to function at an optimal level for prolonged periods. Naturally, this will have a huge influence on in-game performance.

From a performance point of view, the key is to distinguish between what you “need to eat” and what you would “like to eat” and plan around when best to eat what. Chocolate, pizza and the like are not forbidden if you really enjoy those foods, but be aware of when you eat it for example right before a match or exercise. Instead, eat in on the days and times when you don't have to perform.