The concept of the food Diary is OK but it is responsive to what you already ate.
I found it a lot more productive to take out a spreadsheet and write out a menu for a week. Rather than cheating and having to document it I found it way easier to just try and stick to the times and food I put on my spreadsheet.
It takes about 45 minutes on a Sunday night to write out your plan and t is funny how compelling it is once you’ve written it down. Makes it easy to walk by the free food samples at Costco becaseu they are noton your spreas sheet.
Dropped 24 lbs in 15 weeks using this approach. Have gained back 4 lbs since I went off.
Give it a shot. A litte tough the first could of weeks but once you got it down it is pretty easy to copy and paste.