It's important to note the difference between refined sugars (candy) and natural sugars (fruits). Refined sugars are basically fructose (hello High Fructose Corn Syrup).
Refined sugars -- super hella bad.
When you eat the refined sugars, your liver actually traps the ATP, blocking the pathway to the brain, making you still feel hungry.
Great 10 min clip: https://www.youtube.com/watch?v=8ve6XQH68mg
sucrose (white refined sugar) is half fructose, half glucose
https://en.wikipedia.org/wiki/Sucrose
High Fructose Corn Syrup has a variable amount of fructose, but is usually similar to cane sugar because it is used as a substitute.
Fructose does not provoke a satiety response in the human gastroenteric system, unlike glucose.
So if you do eat candy, prefer sucrose to HFCS and glucose to sucrose. Sucrose will be listed on packaging as "sugar".
Lustig[1] says the reason naturally occurring fructose is not as harmful as industrial fructose is that fruit also contains fiber, which slows down the absorption of fructose.
[0] https://thepaleodiet.com/fruits-and-sugars/ [1] https://www.youtube.com/watch?v=dBnniua6-oM