Nothing more complicated than a scale in your bathroom is needed. Check daily and see if you lose weight with whatever combination of food/activity/metabolism you have going on. If you somehow gain or lose weight, eat accordingly.

Using the scale is great if you understand proper nutrient timing and partitioning. What if you don't know the basics of nutrition though? Where do I cut from? What can I add in that will assist with satiety but still reduce overall energy absorbed? Where do I go to understand that these are questions that need to be asked in the first place?