As Facebook is quite limiting in how you can explain stuff, I will use my blog to make it more clear (it will be gone in a week or so. Maybe I'll upload it on my website before then, but otherwise it is just gone).
The first step is to let MyFitnessPal calculate how many calories I burn on a day I do nothing. That's done on this page: http://www.myfitnesspal.com/account/change_goals_guided
I do this by entering "sedentary" as my daily activities and at goal "maintain my current weight". As I weigh once a week, I change my current weight every week and let this do another run, so it takes my weight loss into account when calculating how many calories I normally burn.
While that is what I do weekly, I also do something daily. Namely connecting my Garmin Vivofit 3 to my smartphone and therefore having my actual activity taken into account. Once connected, it will add the extra calories burned with the calories MFP calculated.
So, you see. Yesterday I did 9271 steps. The intensity minutes were something I did on monday and I actually ignore it. But it didn't add any extra calories for today, so you can ignore it for this example as well. These 9271 steps added 315 to what I burned that day, coming to a total of 2815 kcal I should eat if I wanted to remain the same weight.
MFP can also do this, but I prefer working with Connect, as I don't insert my calories in MFP anyway.
I've now calculated how many calories I burn, but I still need to calculate how many I've eaten.
My meal replacers are around 230kcal per meal (±60g, I weigh it myself, so it can be slightly over or under), which comes down 500kcal with two shakes or 700kcal for three shakes. I sometimes eat a small apple or a large carrot, which comes down to ±50kcal. And I might buy something in the supermarket. My favorite mozzarella is 285kcal per package for instance.
I add all those. With my aim being between 700 en 1200kcal a day (green), but I'm okay with 1200-2000kcal (orange) and everything above 2000kcal is an unsuccesful day (red). And that is what I will fill in on the first (tracking) page of my bullet journal:
So now I can see how I am doing with weight loss in general. But it is not very specific in how much I am likely to loose.
To get a better overview on that part, I need the calories that I calculated at the beginning, my burn. Yesterday I've eaten about 1200kcal (2 shakes plus some fat stuff from the supermarket), which means I have a difference of 2815-1200 = 1615 kcal weight loss. In this case, the rounding of to 100-calories is easy (1600kcal). But because of several reasons, I normally use 65kcal as a cut-off point. So 1660 kcal weight loss will still be counted as 1600kcal weight loss, while 1670 kcal weight loss will be counted as 1700 kcal weight loss. One of the reasons is that a kg of bodyfat is slightly over 7000kcal, but 7000kcal is easier than 7200-7300 to make boundaries for. So I compensate for that this way.
That is where the second tracker comes in. This tracker has 13.5 blocks of 70 squares. The use of multiple colors is mostly because it remains visible how much I've lost every day, though it isn't always true. Yesterday was the second blue group on the left (9 squares) and the first blue group on the right (7 squares). Those 9 squares at the left were the last squares I needed for the loss of a kg of bodyfat, while the second group of (blue) squares on the right was my first day of this tracker, as I had made an error in drawing the boundaries of the blocks. So normally, you would do one block at the time. I sometimes work up and sometimes work down, often I combine them. Just what I think is fun that time.
So, that makes the second page. And yes, it has been quite accurate. Since march 17th, I've lost 1.4kg and that is exactly how much I should have lost according to the tracker (1 complete block and 29/70 squares of the second block, which is 41%). In real life, it is very slightly off, as I did have one off-day when I ate 600kcal above maintenance. So I should have only lost 1.3kg. But either I lost some water, or I also lost a fraction of muscle (quite possible of course), the end-result is exactly as the tracker predicted.
If you want to use it with pounds, that's no problem as well. Just split the blocks into two. In that case, you can just split your calories at the 50-point (so 1649 is 16 squares; and 1651 is 17 squares), as it is overcompensated the other way (1kg is 2.2lbs).