[VS1999]

"Impulses" here means the mind. Medication with side effects also effect the body. You're giving three options of altering the mind, body, or environment. On principle I'm against altering the mind and body of millions of people because their environment is shitty. This also doesn't buy anyone any time, it just makes it the new "baseline" normal as companies and society adapt around it like these snack companies you're saying take advantage of people.

[idle_zealot]

Assuming the change really is just limited to being less suseptible to cravings for unhealthy foods, I don't see an issue. That's a big "if" thought. And yeah, fixing the environment in this case would just be a matter of the FDA or regional equivalent resticting the sale and advertising of unhealthy foods, which personally I view the same as anti-smoking laws and would be all for, but the current regulatory climate makes that seem extremely unlikely.

[maxerickson]

Your principle as stated doesn't apply to a situation where individuals have the agency, which I think is a fair assessment of a drug that they choose to take. They are examining their environment and making a choice, not having their mind and body altered by some exterior force.

Which isn't to say that the overall idea of trying to find other ways to make obesity less common is bad, it just isn't a coherent argument for that.