Every food we consume, no matter how healthy it may appear, can become unhealthy if consumed excessively. For top-level athletes who will do everything to be the best, what you fuel your body with every day (especially tournament day) is crucial.
Food is a direct source of ATP (Adenosine Triphosphate), a molecule that provides energy. The more food we have in our bodies, technically the more energy we should have. With that being said, we need to make sure we have the right type of energy in our body, so we can get through numerous routines without having an energy "crash." We want to make sure all our meals have incorporated the main macronutrients. Macronutrients (macros) are your staples: carbohydrates, proteins, and fats. Carbohydrates are used for quick energy; this is what our bodies need both the night before, and day of competition since we will need to have an abundance of energy for routines. Protein is nutrient-dense, it will stay in the body for a longer amount of time, and help feel satisfied longer (not to mention, proteins are literally the building blocks of the body). Fats are the last source of energy to be burned off, so in case the tournament goes later than expected, you're going to want to eat this so you don't run out of fuel.
With all of this being said, here are some examples of foods I recommend incorporating into your diet tournament day as well as some other foods to avoid. For breakfast, EAT: eggs, yogurts, avocado (healthy fat), turkey (lean protein), legumes, fruits (blueberries are a good choice because they have antioxidants), a source of carbs other than fruits like potatoes (not fried). DON'T EAT: sugary cereals, greasy foods (these can make you feel sluggish) or granola bars (most of these are just sugar and don't provide much of a nutritional value). If you would like to eat pancakes or waffles (my favorite) for a carb source, make sure there is protein incorporated with the meal. You can also add peanut butter to give you both protein and fat that will be useful for later on.
Now that we talked about breakfast, let's discuss lunch, ring side snacks, and supplements. For lunch it would be helpful to focus intake on an excess amount of carbs (pasta, rice), as well as a protein of your choice (i.e., chicken). For anaerobic athletes like sport martial arts competitors, it is recommended to have about 30-35g of carbs pre-competition (within the hour of competing). It's also recommended to consume 1.0-1.6 g/kg BW (body weight) of protein pre-competition. Some snacks that I find helpful to keep ringside are rice crackers (you can add peanut butter to these as well as mentioned above the fats will stay with you). You can also eat nuts and fruits. I always make sure I have an apple with me as it is a quick source of natural sugar and can give me a boost for my forms.
However, if you have a sweet tooth like me, don't worry, you can eat the sweet of your choice in moderation ringside if you feel it can help your performance. Other supplements like liquid carbohydrate packs are beneficial; I use them about 5-15 minutes before my divisions are up and they provide me with a ton of energy I can feel throughout my whole body. When taking supplements like these be mindful of caffeine concentration (if any), as caffeine is not ideal for children under twelve years old. Additionally, energy drinks should not be consumed by children for these are known to cause an array of side effects (heart palpitations, insomnia, and even dependence that can lead to overdose.) This "band aid" fix for energy is not worth the stress that is put onto the heart, especially for younger competitors.
With everything mentioned, it is important to find what foods work best with you. It can be helpful to stick to the same meal plan for each tournament once you discover the best recipe for your optimal performance. Having a good nutritional game plan is part of having an intelligent competition IQ.