Drinking sufficient water is vital in supporting wrestlers. It helps regulate body temperature and lack of water will decrease metabolism, strength, and stamina. It also helps quicker muscle recovery. Water should not just be consumed during a meal, but throughout the day. Wrestlers should carry around water bottles during the day. Two rules of thumb for water are:
If you are even a little thirsty, you are dehydrated.
If your urine is yellowish, you are not drinking enough (your urine should be clear)
It is important that wrestlers stay hydrated during the day, but it is especially important for wrestlers to come to practice well hydrated and stay hydrated during the work out as much fluid will be lost during practice. How much water to be drinking depends on the gender and weight, but generally, all wrestlers should be consuming 2L to 3L of water throughout the day to maintain optimal muscle performance and prevent injuries due to lack of water (such as cramps). Drinking before and during practice is very essential as well.
Here's an article on the importance of hydration for wrestlers.
Eating breakfast is crucial for wrestlers. As counter intuitive as it sounds, eating breakfast helps lose weight more efficiently. A good breakfast will start up the metabolism. This allows the wrestler to have more concentration and strength throughout the day and also intake nutrients effectively. Wrestlers should eat simple and complex carbohydrates and protein in the morning. Just eating simply carbohydrates is ineffective. It is also best to leave 12 hours between dinner and the breakfast the next day.
After breakfast, wrestlers should eat frequently with emphasis on taking more calories of the day before mid-afternoon. If the wrestler is on a , say, 2000 calorie diet per day, it is better to eat 5 meals with 400 calories each, than, 2 meals with 1000 calories. Bringing small portions of sources of complex carbohydrates and protein (with a little fat) to eat throughout the day will help improve athletic performance. Then, after practice, wrestlers should eat a good source of complex carbohydrate and protein (about 200 - 400 calories worth) within 1 hour after practice for optimal recovery. Then, finally dinner which should be lighter than most other meals. Dinner should be eaten before 8pm at the latest (to give the 12 hour fasting period before breakfast). Do not eat 2-3 hours before you sleep. And, wrestlers must get good sleep! Sleeping is the easiest way to lose weight (you literally lose weight doing nothing) and it is very important for your body to recover to endure training the next day.
Contrary to the common belief, a wrestler who is good at controlling weight and performing well at practices are constantly eating (of course, eating smart and well calculated).
Here's a resource for the timing at which you should eat: https://www.eatingwell.com/article/7826585/best-times-to-eat-for-weight-loss/
The day before the day of the tournament, ideally wrestlers should be about 1lb under their weight class. By being 1lb under, wrestlers can get a good dinner to recover and still make weight the next day. If wrestlers are over by a 1lb or so, usually (depending on the wrestler) they will lose about 0.5lb - 1lb during their sleep. If they are over by more than 1lb, they may need to go out for a jog/exercise to lose some more.
Here's an article on some advice for eating on the day of the tournament.
On the day of the tournament, before coming to school, wrestlers should check their weight. If they are under weight (say, by 1lb), then they can eat 1lb worth of breakfast. If they are exactly on weight, get something very light (like, 1 banana, 1 cup of orange juice, 1 bar) to eat and go to school (during the travel, wrestlers will lose about 0.1 - 0.5lb). If wrestlers are over weight, don't drink or eat and come straight to school. Wear lots of warm clothing so you can sweat it off during the travel.
After wrestlers successfully weigh in, they are free to eat and drink (they are free to eat, but it does not mean they can eat anything they want). If a wrestler has been cutting weight for a while, their body is not used to eating "normally". After weigh-ins, it is important that wrestlers get hydrated and also consume carbohydrates. Consuming protein and fat on the day of the tournament does not help much. Wrestlers should focus on replenishing quick sources of energy (carbohydrates). They should not eat full as they will have to wrestle in about an hour or so. Replenishing the body with water and carbohydrates after each match is important to be able to keep going for the whole day. Starting out with soups or fluids and small amount of meals with fast absorption is best.
After the tournament, your body is tired. Carbohydrates along with protein and fat are needed to recover. Usually, the next day is a day off. On the day off, it is important not to go crazy with your meals. Getting a little more calories than usual (if you have been on a very low calorie diet) is fine but not a lot more; as it will make it harder for you to make weight (most likely the week after).
Watch the video below for some good and bad ideas for breakfast:
Read pages 6 - 10 of the PDF for ideas on when and what to eat on tournament days.
Refer to the sample meal plates depending on the type of training recommended by the United States Olympic team nutritionists.