Many people have the mentality that "I worked out so I can eat what I want." Jade Jenny, head CrossFit coach and owner of Champlain Valley CrossFit shared that "reducing belly fat ultimately comes down to how you eat."
Daily calorie amount is what matters. If you chow down on a post-workout "snack" that has twice as many calories as your workout burned and it puts you over your daily calorie amount, you'll gain weight.
After a workout, go for something small that's around 150 calories. Make sure it offers protein and carbs to refuel and aid in healing and keep you satiated until your next meal.