With that garbage can I really recommend NOT having a kitchen sink, and only using the pedestal kind in the bathroom. That way you can put your dirty dishes in the can for $10 each as well as garbage. My Sim kept on trying to wash the dish before I could stop her, so I just sold the sink. Now she puts her dirty dishes on the counter, and I can move them to the trash for cash.
I think my Sim Charlee ended the challenge thinner than she began it. I only fed her eggs, or eggs and toast, and only when her hunger got completely into the red. Her other moods were high enough that being uncomfortable from the hunger never bothered her. She ate a little less than once a day with no problems, and even less once I got her the reward that makes her not hungry. For my second try, I made my new Sim as skinny as she could go, and even removed her meager curves. I wanted to see exactly how much weight she would put on during the challenge.