I have reconsidered what you said, and reanalyzed my diet. My conclusion is that nuts are the key. I tend to balance my weight with nuts. When my weight is on the high side, I will eat very little or no nuts or seeds. When my weight is on the low side, I might eat plenty of nuts and seeds. I looked up the copper and zinc content for the various nuts and seeds, and did notice how huge their copper content is. I decided that I shouldn't be taking any supplemental copper during the periods when I am eating plenty of nuts, but should still probably take 2 mg a day when I am avoiding nuts.