Assumptions don't get you anywhere.
Do you think they spend so much on lottery tickets because the rich so unfairly keep them out of derivative trading?
If all you can afford is ramen/bread/fast food, your body makes you overeat to get enough other nutrients (eg. vitamin C, B).
The second is that your insulin goes crazy with all those simple carbs and sugars (carbs are cheap, unlike protein, fish and vegetables, and get metabolised to glucose) so you get massive blood sugar swings. The low side of those makes you eat more and get fatter.
Lottery tickets are a strawman. Or, to quote a science fiction novel that I can't quite remember: "a tax on hope."
Vitamins pills and vegetables are reasonably cheap. And anyway if deficiencies caused obesity, the rate would drop off dramatically over some threshold income.
Lotteries matter because that's where poor Americans spend about 10% of their income. Taxing the rich to destruction will not fix that.
http://www.guardian.co.uk/commentisfree/2011/dec/14/obesity-...
http://www.huffingtonpost.com/dr-mark-hyman/not-having-enoug...
10% of a poor person's income turns out to be about $25/week according to this article: http://www.dailymail.co.uk/news/article-2123448/Poorest-peop.... Hardly earth shattering or likely to lift them out of poverty if they somehow manage to save it.
Re. lottery spending, they are losing $12 a week! That is $600 a year! That could buy premium multivitamins, an extra several eggs a day, rather a lot of cheese, with money left over for the occassional meal out.
The problem of most poor Americans is not resources, it is the deployment of them.
Hmm... the blatant gambling nature of both of those makes it a good analogy.
Problem is, if income/wealth inequality is too severe, those guys are the only ones with money to contribute. So on some level, you need a certain level of income/wealth equality just to have multiple classes/brackets with enough excess income to contribute to the national welfare.