One thing that really helped me lose weight was learning to read labels. I mean that two ways. One is learning what to look for, how to read them, how to make sure you understand what a portion size is, etc. The other is to learn to read labels the way you learn to look both ways before you cross the street.
The other night in a CVS pharmacy, I happened to notice a shelf with some of those Hormel "Compleats" microwave meals and there were a couple of packages of their Rotini & Zesty Marinara Sauce. If you look at them casually, they look like the exact same product. If I read the label of one and decided I wanted to purchase two, I would have just grabbed the other one without checking its label. Closer inspection however shows they're not the same thing. The one on the left has 290 calories, one cup of vegetables and 8 grams of whole grain. The one on the right has 300 calories, half a cup of vegetables and 28 grams of whole grain.
I'm guessing the one on the left is from an old shipment and the one on the right is the new version. And I'm wondering if the changeover is accomplished at least in part by cutting back on sauce and putting in more pasta.
I don't have a big point to make here other than that you need to study labels to know what you're getting. Sometimes, a product changes without it being too apparent.