These "most valuable food brands" make products that kill people. They've become the tobacco industry of our generation.
If you want to understand why the above claim is true, I encourage you to watch "Processed Food: An Experiment That Failed" by Robert Lustig, M.D., M.S.L. a whirl. Link: https://www.youtube.com/watch?v=pvgxNDuQ5DI
Also, Sugar: The Bitter Truth: https://www.youtube.com/watch?v=dBnniua6-oM