Smoothies and protein shakes are solid tools here. Liquids sit easier on the stomach and leave faster, so they ease nausea and discomfort. Plus they pack protein for fullness and muscle when appetite tanks. They fight dehydration when solids are rough. And portions feel adequate even when small.
Weight loss usually does make people happier at first. Though I'll say sometimes folks expect it to fix stuff it won't. People didn't suddenly treat me nicer or anything after dropping weight - just stayed the same. But at least I feel better in my own skin now.