Present while Overeating

This afternoon I was randomly munching on cereal while playing battle ship with my son and completely aware I am not hungry at all. I have been working on 100% commitment to my meal plan which I am not clearly there yet. I am frustrated and disappointed that I kept forgetting my why and then mindlessly eat. I can’t say that it was habit. I was eating and thinking I am not hungry and then looking my TDL from this morning and am like-oh yeah- I am supposed to be 100% committed. I am wondering how I can be so focused in the morning and then its like I black out in the afternoon. Do you recommend reminders? Phone alerts? Any help would be appreciated.