The consensus from the most sensible people is, do the diet you can stick to, in the end just eat less. That’s most important.
It wouldn't require a whole lot of thought to come up with an all candy diet that supplied the minimum necessary nutrition. How broad is our definition of "candy" for this? Are you willing to consider candied fruits, vegetables, and bacon? Chocolate covered things? How much dark chocolate would we have to add to something to consider it candy?