Noone has added to this post, so I wanted to add a bit. It really depends on your goals, if fat burning or bulking. If you are fat burning though, the muscles use glycogen when active but when at rest or inactive the muscles/body prefer the fat substrate for fuel. Fats that come from our fat storage. It is a scientific fact that when muscles are being used, they use glycogen storage, but when at rest they use fats. If we go to bed with low muscle glycogen storage and the muscles are inactive, what will the body use as the fuel of choice? Fats, of course. When we are sleeping our insulin levels are low, our GH increases, therefore fat utilization increases. When the next morning comes our bodies will still be utilizing fat as the fuel of choice because glycogen stores are low. Instead of eating a high carb - high glycemic index breakfast that will replenish the muscle glycogen stores, why not eat a low carb - low glycemic index meal? Our muscles will be forced to continue burning fat for fuel to preserve the storage.