Endorphins are composed of amino acids. Certain triggers release them to the brain where they attach to the dopamine receptors, which are the ones that make you feel happy. They can determine your mood, pain threshold, and even your stress level producing a natural high.
Each and every day we do things that trigger endorphins to be released. The levels varies by action to action and quantity to quantity.
Addiction to any of the above may be caused by the craving for the Endorphin release whether it be Alcohol or eating. To have an easier time quitting any addiction, substitute a few other actions that release endorphins. Laughing is pretty easy. Do it with insanity. Eat curry and chocolate (don't mix). Go walking for a long time.
Daily quantity of cigarettes doesn't always indicate the ease in which a person can quit. Person "A" smokes 3 cigarettes a day. Person "B" smokes one cigarette but puffs it up as fast as they can. Person B usually has a much harder time quitting because the brain craves the higher release. The sames goes for alcoholics and other substance addicts.
Runners high is attributed to released endorphins that can cause runners, who were previously tired, to feel like they just started the race. Endorphins can make running an addiction. At the end, we feel happy, extremely relaxed, and food and drink are delicious with quantity being of little importance. Sleep is always restful and deep.
Many teens cut themselves for a physical release of the emotional pain they have. Cutting releases endorphins and confusingly makes them feel better. The effect is temporary, and guilt builds as they reflect on their age and "unnatural" pleasures to cope with it. It's estimated 1/200 high school girls cut themselves, but it may likely be a much higher rate. Teen Cutter Poetry, Suicide Poetry, and Teen Depression Poetry are among the most written poetry by teens on the web. Poetry sites always have plenty of depressed kids at any given time.
So we've seen endorphins to be a factor of addiction. Think of the little kids that go to McDonalds. A lot of sugar will release endorphins. The cokes have like 20 sugar packets. A lot of fat will release endorphins. The burgers are nothing but a ball of fat with preservatives. Food with lots of oil release endorphins. The fries are boiled in oil. On top of that, the kids are given a playground, a little toy and a cute bag for future association to the food. They are helpless against future craving. Uneducated, less wealthy, and usually overwhelmed parents parents find it a inexpensive and fast solution to cooking, but the organization should not be supported.