Looking for a superfood loaf/muffin recipe for my grandfather

Hi! My grandfather is 90 years old, and I’m worried that he’s not eating enough or getting enough nutrients. His appetite is relatively small, but he enjoys a slice of banana loaf or a muffin at lunch, so I was hoping to make him a loaf/muffin he could have at lunch to sneak in a few extra calories and nutrients! Something with a nice dose of healthy fats, protein, and fibre would be amazing (and some hidden vegetables wouldn’t hurt either😊)

He likes something sweet but not too sweet, and moist seeing as he is at risk of choking.

Thank you so much for any suggestions you may have :)