Solver/Goal Seek HARD Optimization Issue

Thanks for taking the time to help - I will lay out what my data looks like, what I am trying to do, and what I have attempted already - The short and sweet of it, however, is that I am looking to use some type of optimization feature. I have also included a sample file of my problem!!

WHAT MY DATA LOOKS LIKE:
I am analyzing food as nutrition compares to user enjoyment -- I have a list of different types of food in Column A, in Column B is a numerical score that I have given the food based on nutrition (Nutrition Rating). In Column C I have a numeric score given to each food based on how much people enjoy eating it (Enjoyment Rating).

WHAT I AM TRYING TO DO:
I would like to run an optimization analysis to find how to maximize the Enjoyment Rating given that I constrain the number of food options (say there can only be 5 foods) and that I constrain the Nutrition Rating (nutrition rating cannot exceed 100).

THE TROUBLE AND WHAT I HAVE DONE:
I have not been able to find a way to optimize while keeping the nutrition value of each food the same and selecting the best combination of 5 foods from a list of 100 foods. I have attempted to use Goal Seek and the add-in Solver, however, I am having trouble setting this up to use the list of foods and keep the nutrition value the same in order to maximize the sum of Enjoyment Rating which also stays the same. In other words, I do not know what to use as the variable that goal seek and/or Solver changes.

All help is extremely appreciated and welcome!

Thanks!