Yes, a food journal is a must. Daily recording of your grub intake.
Regular weight monitoring - I weigh and record it daily, I record my exercise, too.
I am not saying others need to weigh DAILY but do it often - weekly or bi-weekly or use a pair of jeans to monitor your size.
You cannot go from following the weight loss regimine to gangbusters or you will eat yourself right back to your former flabby days.
Permanent weight loss = permanent life style changes.
It may sound boring & yucky to have to monitor for life, to eat restricted portions, to avoid some trigger foods, but you all know the alternatives: Flabdom Forever or Thinsville Forever...I have been morbidly obese and I have been thin; I choose the latter any day!