Reading the article I saw this:
It helps greatly if you are willing to eat similar foods day to day that are easy to track
THIS is my problem. I tend to rarely eat pre-packaged processed food, or simple things. I cook from scratch, large batches of things, to eat as leftovers for most of the week.
Let's say since greens are in season now, I cook a HUGE 6-7QT pot of greens, Basically the only fat in the thing is 1lb of Andouille sausage. This pot will easily be 6-10 portions/meals. Granted this is a simple dish with few ingredients, but what about the same size pot of mushroom chili? Or something else that is complex and has a lot of ingredients and I don't really know how many meals will come put of it, or maybe it is something I'd combine with other leftovers into a different dish, for example I might grill out a bunch of eggplant, onions and zucchini...I might eat some in a salad, or maybe some as a wrap with yogurt sauce..etc.
The thing is...I rarely cook anything simple with an easy to find and read ingredients list, It would take forever to figure what the calories and all were from what I cook since so much of it is fresh vegetable and meat based, etc.
I dunno what a portion would be in so many cases...although it is largely healthy food.