I buy dark chocolate when I should not. But I buy for the immediate moment. I have no problem buying less than my impulsive self ideally might desire. I run out of the stuff quickly, even though when I run out part of me wishes I had bought more (this is similar to "gamma discounting.")
I need only make fewer trips to the store. Each time I go, I should fill the cart with milk, grapefruit juice, and cereal, so I need not return for a long time. Fewer store trips mean fewer chances to be weak. Being myopic in my weakness of will, I won’t much adjust using larger chocolate inventories.
Chocolate below 70 percent is not worth my while.
The best solution to my self-constraint problem is to tell my wife where the chocolate is hidden.
Sadly, I know she does not like the 85 percent.