I was reading a bit of research the other day about serotonin and diet. Here's an interesting abstract on the subject:
"Current findings on the relationship between excessive appetite for carbohydrate-rich foods and mood disorders may explain repetitive weight gain or the inability to lose weight among some obese individuals. Obese individuals who crave carbohydrates, exhibit positive changes in mood after carbohydrate intake; individuals suffering from Seasonal Affective Disorder experience a craving for carbohydrate-rich foods in association with their mood disturbances. Brain serotonin may be involved in these disorders of affect and appetite; thus therapies that mimic the effect of carbohydrate intake on the synthesis and release of this neurotransmitter may be useful in treating obesity arising from these causes."
People eat junk food for a reason - it gives a temporary high by boosting serotonin. But this is sort of the "cheap" way to get serotonin. The better way for the long-run is to boost serotonin by making lifestyle changes. Four of the biggest lifestyle factors that affect serotonin are:
Getting sufficient sleep
Getting regular sunlight
Aerobic exercise, especially dance
Another way to get serotonin is through the use of antidepressants. But like food, this type of "shortcut" can lead to problems. Here's one quote (from this article ) about how antidepressants affect sex drive: "The more you bathe people in serotonin, the less they need to be sexual."
So here's what I think is happening: evolution set people up to "chase" serotonin via sex and dance. (Sufficient sleep and sunlight came naturally during ancient times.) Nowadays, people can get serotonin via cookies and such, with some getting it through antidepressants. But these type of strategies do not bode well for the long-term. Maybe the serotonin receptors get burned out or dulled this way. And of course, there are the health issues that come with long-term consumption of refined carbohydrates.
In this framework, I can see dancing as a good tool for weight loss. If a person is cutting down on sugar and refined carbs, then you want to replace that with something that boosts serotonin like dancing. Dancing also burns calories but its biggest benefit may be in the seronin high it creates, replacing the artificial high a person can get from refined carbohydrates.