It's very true. So easy to just mindlessly snack and not pay attention to serving size. I always tell people that they should keep a food journal for even one week because the results will shock them. I did that once, when my postpartum weight loss stopped before I hit my goal weight. I knew it was dietary but I wanted to know what I was doing wrong. As it turns out I had a lot more milk, cheese, and nutella than I realized, and once I started making changes I started losing again. And I wasn't even overweight; I was at the higher end of my normal BMI range, but even at that weight food was the reason I wasn't thinner, and even though I wasn't overeating enough to make me fat I still was out of touch with just what I was eating through the day. I can only imagine how much worse that is for someone whose life revolves around food - they must lose track entirely.