But drugs do tap into the natural reward pathways used by food (and other things). Which is why I think that Rat Park is relevant when we look at the ways food, eating, fat, and weight are studied.
Why? The Rat Park experiment, in a nutshell, shows that few rats become addicted to morphine when they’re given an interesting environment, one similar to conditions they’d find in the wild, where they’re able to interact with other rats, play with toys, and exercise on wheels. Rats kept in small cages, on the other hand, with nothing to do but eat, sleep, and self-administer morphine, will self-administer until they die.
I touched on this a bit in an earlier post, We aren’t caricatures. One problem with the way that lab animals are studied, including the animals they use to study fat, is this:
Without toys or exercise wheels to distract them, the mice are left with nothing to do but eat and sleep—and then eat some more.
The fact that mice and rats are studied under these conditions not only causes problems in general in applying the results to humans who do have more to do than eat and sleep–it is also one reason scientists applied the addiction model to eating in the first place. It seems likely that rats would not act “addicted” to food (or certain categories of food) if they weren’t so often kept in small cages with nothing to do but eat and sleep.
I suspect part of why humans with lower socioeconomic status are fatter on average is the same reason(s) why they are more likely to be abuse drugs. (Exactly what that reason is, I’m not sure. It could be stress, it could be the need to escape an unpleasant life, it could be that–like the mice–their life simply has more periods of boredom.) They are still subject to most of the factors making people with higher SES fat, e.g. genes and plentiful food. But there are multiple reasons why people become fat, and this could be one reason why people with lower SES are more likely to be fat.