It's not too late to change your eating habits to fuel your best Open performance yet. No, this does not mean cutting all carbs out of your diet - it's actually quite the opposite! Quantity is key for optimal performance and recovery.
If you follow a programmed set of macros that are specific to your goals, there won't be much to change here. The only recommendation would be increasing your carb intake surrounding your workout. Glycogen is your body's preferred fuel source and the primary fuel source for CrossFit specific energy systems, so you want to ensure you have enough fuel to perform and recover as quick as possible.
If you eat intuitively (aka whatever you want, whenever you want), you may want to increase your consumption of starchy carbohydrates in these upcoming weeks. Starchy carbohydrates include high glycemic (eg. white rice, white bread, fruit) and low glycemic options (brown rice, quinoa, oats, root vegetables). The best time to consume low glycemic options are 2-3hrs before your workout so that you have a slow and steady release of energy. The best time to consume high glycemic options are immediately post workout to kick start the recovery process (especially if you plan a re-do!).
If you wake up with at least 2-3hrs before attempting the WOD, you can consume a well balanced meal of protein, carbs and fat (eg. eggs, toast, potatoes cooked in coconut oil). If you only 1hr or less before attempting the WOD, you want to stick to quick digesting protein and carbs (eg. a protein shake with oats in it). Stick to foods and supplements that you are familiar with, as you don't want to stop because of digestive issues - the workout will leave you with more than enough pain! You may already be dealing with a queasy stomach from the stress of the workout so keep your fibre intake low beforehand.
Immediately following the workout, consume a 2:1 or 3:1 ratio of carbs to protein to optimize recovery. The best sources of carbs to help you recover from the massive stress of going HAM during the workout include high glycemic sugary options. Fruit is a great source of high glycemic carbs, paired with other options include white bread, white rice, a carb powder or a drink like gatorade. Ensure your protein source is low in fat so that you absorb the protein as quick as possible.
It's easy to forget to eat right after your workout when you're watching your friends compete or stewing on your performance... High cortisol levels may prevent you from feeling super hungry immediately post workout, but if you plan on attempting the workout a 2nd time around, it is especially important to ensure that you are getting that post workout meal in as soon as possible. This is the only time that you are going to hear me say that sugar is a good option here to reduce cortisol levels as much as possible post workout - so eating a protein bar, fruit in your protein shake, or simple sources of carbs like white bread (hello bagels!) is totally fine! If you have more specific questions, don't hesitate to reach out to me via email.