Darkoz, would all the IF people disagree with your comment on breakfast? I thought timing didn't matter etc etc... or is this question about to open a can of worms?
It's not whether or not you have breakfast it's what you have for breakfast
Ya not having breakfast will decrease BMR
Even Berkhan admits there is no evidence to suggest you're not going catabolic
That's why I opt for a PSMF instead
If you want breakfast, go for high protein and zero carbs. You will get all the benefits of fasting still. Go low fat as well as fats slow down absorption.
Basically with nutrient timing...
High protein, low carbs/fats
Sugars before/during training
Lots of carbs after training
Each meal after training, lower carbs and go for lower GI, increase fats
Last meal should be fatty to give slow absorption of aminos thru the night