I have found that when I use only part of a bell pepper, it keeps longer if I first use the flesh from the bottom or sides of the pepper. I cut of slices from the sides, leaving the top and core intact. The core and seeds seem to keep the pepper from beginning to spoil.
I learned the hard way that when handling raw butternut squash (or any other orange squash) that it's a good idea to wear latex gloves. Butternut squash has enzymes that can act like a chemical skin peel. My fingers turned orange and the skin got really tight and then started peeling over the next day, but only on the hand touching the raw squash. My right hand, which held the knife, was fine. Had to research online to figure out what happened.
Eating healthy can take a lot of prep time. I cut up and prepare salad fixings for 2-3 days at a time. I make bags of chopped cucumbers, tomatoes, etc. and keep them ready for a fast, delicious salad. Just grab a serving from each bag and add to your plate. Yum!