I've been eating pretty small portions. I eat stir-fry almost every day and usually I think about how small it is but I'm never noticeably hungry afterward. Today was stressful for me so I didn't eat all day and instead just sipped on water. I finally got hungry and made myself a HUGE stir-fry with chicken, peppers, water chestnuts, pea pods, onions, green beans, and broccoli and a one-minute muffin (a low carb muffin recipe using ground flax, one egg, butter, and seasonings) topped with cream cheese. I noticed that I ended up making a ton of food, but didn't think much of it. About halfway through my meal I started getting full but kept eating. A little while later I realized that I couldn't finish it! I wasted almost a whole muffin and a bunch of veggies. Now that I think about it I should have covered it and had it with breakfast or lunch tomorrow.
All of my food rambling aside, I usually describe this as my stomach shrinking because I'm eating less, but I started thinking about it and I realized that I'm not sure exactly what happens. Does the stomach really shrink when you eat less? I went from being able to polish off half of a pizza with a soda and now I'm getting stuffed off of half of a muffin and stir-fry. Could it also be that I'm eating more filling foods?