It's Sarah again :) As a professional triathlete, I find a rigid diet is necessary to maximize my performance at a world class level. But it takes time, planning, and a lot of effort. Most amateur athletes don't have the time, desire or need to be so structured. So, I don't recommend it for most people. Trust me, eating six pre-planned meals a day plus snacks is exhausting!
What I've found having come into contact with amateur athletes my entire career is that following a few basic principles will help you develop long-term healthy habits.
Watch your macros
Don't obsess over this, but try to make sure each meal has a good balance of carbs, fats and protein.
Fuel within 30 minutes of your workout
Getting protein, carbs and fat within 30 minutes after finishing your workout will help replenish lost resources and promote proper recovery.
Eat plenty of unprocessed foods
Avoiding processed foods is a must and will get you most of the way to a healthy diet. Once you've done that, make sure you're eating enough food and that it's coming from nutrient-dense sources.
Don't be afraid of carbs
Rather than shy away from carbs, learn to use them to your advantage as a performance enhancer. Quinoa, rice, potatoes, oats, fruit and veggies are all excellent sources of energy.