Well, uh, working. The less you make per hour of work means the more hours you need to maintain a normal standard of living. Obviously there's variance in standards of living, but wealthier people don't typically work two or three jobs. Poor people do, I've met people who do. The reality is that at 12 dollars an hour, 40 hours is just not gonna cut it.
And it's a little more complicated than even just that. Another reality is that, at 12 bucks an hour, nobody is going to be giving you a steady 40 hours. You need extra shifts for buffers, and your shifts will be shorter.
Sure, working 50 hours a week across 7 days isn't technically more than 50 across 5 days. But it does certainly drain your will to live a lot more, from what I've seen.
Poor obese people aren't working so much they don't have time to cook.
And using numbers to support that idea doesn't work, it actually goes against you. A small (much smaller than most obese people will eat in one sitting) fast food meal costs about an hour of minimum wage! Buying stable calories in cereals where the time to buy and cook them can be amortized into many more servings can be amortized is actually cheaper and also takes less time.
In the US, obesity rates rise as income drops, but it continues to rise beyond the point at which income drops below a full time federal minimum wage income.
It's over-eating and under-exercising. I know this is hard for certain ideologies to accept because it means obesity is not inflicted upon victims against their will and beyond their control. If you really need to minimize their agency and responsibility for their choices you can call it addiction to food and addiction to sedentary lifestyle if it helps.
I’m pretty sure this has reversed in recent decades. Wealthy people are far more likely to work long hours than the poor.