Not just in the mornings!!!!
I see people are still saying it only matters in the mornings. It matters all day long!!
By keeping your blood sugar on the low side as much as you can (especially during the 2ww), you are giving your pink blastocyst as many hours out of the day as is possible for it to divide in its preferred, low glucose environment. You don't need to starve yourself, just don't snack every half hour throughout the day, don't eat big huge meals that take forever to digest, and make sure you're good and hungry before you eat again.
I'm assuming people are confused because of the skipping breakfast thing, but the reason you should skip breakfast is because you've already gone for so long without eating, it just gives you a nice long run with no food intake and blood sugar on the low side (meaning your pink blast has that much longer to divide and implant). That doesn't mean it's no holds barred and eat whatever you want for the rest of the day, it's best to keep your blood sugar on the low side.