What is carb backloading?
This approach requires you to eat a low carbohydrate diet up until your evening meal/post workout.
Why does it work?
It allows your body to become more efficient at burning body fat throughout the day and also improves insulin sensitivity, meaning when you consume carbohydrates they will be driven into muscle more effectively reducing the chance of storing them as fat. It's also a very practical approach as many people grave carbs later in the day!
Who is it useful for?
Anyone who ideally trains in the evening and is looking to lose body fat. If you have a substantial amount of fat to lose (as a guy you're over 25% body fat) you would be best off beginning this process with a period of time (between 2-4 weeks) eating low carb across the board before brining in this dietary structure.
What if it's a rest day?
In this situation I would be looking to reduce caloric intake and the same goes for overall carb intake. Still keep that carbohydrate based meal structured into your evening, but simply reduce the portion.
What are the best carbs to use?
The obvious answer is to tell you all the natural, wholesome stuff like white/sweet potato, rice, oats, quinoa, root vegetables etc which are fantastic, nutrient rich options. That said, don't be afraid of the naughtier stuff too. If you love a Kinder Bueno or a couple of Hobnobs, this is the time you can get away with it. *DISCLAIMER* Portion control is critical with these kinds of foods. Six Kinder Buenos or a whole pack of Hobnobs is pushing it.
My best suggestion is to have a portion of natural, wholesome carbs and one not so natural portion of carbs that might be your guilty pleasure. This will help you get the best from the carb backloading approach and keep your sanity in the process!
What about fats and protein?
Fats can be moderate to high through the day but I would suggest keeping to stereotypically healthy fats here. So eggs, oily fish, nuts, avocado, olives, red meat etc. Foods which contain high levels of manufactured, poor quality fats will also most likely have a ton of sugar in too so that rules them out of the carb backloading approach anyway.
Protein should say consistently high throughout the day to ensure healthy growth/maintenance of muscle tissue. Aim to include a protein source in every meal.