What kind of “poor” people are we talking about, exactly? The OP (or his source) mentions “the Caribbean”, but that’s a big place, with people of all kinds of social/economic background. Are we talking about homeless people on the streets, single mothers on welfare or minimum wages, subsistence farmers or what? Or are we just comparing countries by GDP correlated to body mass index?
My experience is that diets in the Caribbean are bad due to the fact they are small islands which rely very heavily on in imports, and those imports tend to be processed food not fruit or vegetables. I can’t say I’ve noticed any different attitudes towards weight (except for an increased likelihood of older female relatives to call their nieces/granddaughters out for “gettin’ thick”)
I have heard (though this is not from personal experience) that south pacific nations had a completely different attitude towards body weight. In Fiji the word for thin and sickly are one and the same, larger body shapes were completely desirable. Eating disorders were completely unknown until the nation got TV for the first time in the 1990s. Since then incidence of them has exploded. Is it possible the OP got the Caribbean and South Pacific confused?
I think that the Caribbean is a good starting place. There are wealthy countries like Europe. There are horribly destitute countries like Ethiopia.
And then there are countries with a large, poor working class–like Jamaica (which I seem to recall might have even been the focus of the TV report, among others). 
The poor are fatter because calories are plentiful, over-eating is more satisfying than is calorie-cutting, and generally there is less of a cultural premium placed on “thin” for the poor than for the rich.
The idea that “healthy” foods are expensive and keep you more thin is hilarious to me. It’s not more expensive to eat a skin-free chicken breast portion than half of a fried chicken. It’s not more expensive to eat less of everything you eat. It’s just less satisfying.
The idea that a lack of education is the culprit is equally hilarious to me. The pretense that the poor are too stupid or too uneducated to figure out that thinner is healthier than fatter is a bit of an insult to them, I’d say. But ask a few if they think fat is just as healthy as not fat, and decide for yourself.
I’ve noticed something like that too. Why would that be?
My guess is that the kind of poor societies we’re talking about, don’t have disposable income for luxuries like new cars, expensive clothes, various other luxury goods, services and entertainment that comes with disposable income. But food is an affordable “luxury” and it’s relatively abundant and often stands in as a kind of replacement for other comforts of life that they can’t generally afford.
because losing weight and keeping it off requires surplus time and energy.
Losing weight is viewed like peacock feathers or a luxury sedan. It is a way to signal to the outside world ‘I have surplus resources, therefore am successful’.
Fighting your biology to lose weight requires you to have access to healthy food, the time to prepare it, the money to hire help if need be (cooks, personal trainers, etc), the time to go to the gym, the mental energy to calculate caloric intake vs output each day, etc. All these things require mental energy, time and/or money.
Poor people don’t have the time, energy and/or money to do that. If you have 2 jobs, work 65 hours a week, have 2 kids you are raising by yourself, can barely afford $5 a day for food, etc you will not have the time, energy or money to focus on weight loss and weight maintenance. If you have nannies, cooks, lots of free time and are not as encumbered by responsibility you have far more time, money and mental energy to devote to weight loss.
For the most part, lots of people don’t really even care if losing weight makes you thin, just that you lost weight. If someone starts at 40% bf and ends up at 20% bf, people will congratulate them. They won’t congratulate the person who was naturally at 18% bf by being a lazy couch potato.
It absolutely is! To eat the chicken breast you: A) have to discard the rest of the chicken. B) Butcher the chicken so only the breast remains, and remove the skin from the breast, or (more realistically) pay someone to do that for you if you don’t have the time. An of course the calories from that meal probably aren’t from the chicken itself but what you eat with it, and the cheapest option there are going to be mashed potatoes or fries.
So let’s take the Caribbean as example. Do I understand you correctly if I infer that you want to compare the average income/ BMI quotient nation by nation (still restricted to the Caribbean nations, of course)? Or is your (or your source’s) claim rather that the poorest people of poor (Caribbean) nationality tend to be rather fatter than the poorest from not-so-poor Caribbean nations?
In any case, we must see facts first. Stats, please!
Um… actually, it can be cheaper to eat the fried chicken.
The store I work at sells cooked, ready-to-eat chicken as a loss-leader. Yes, the fried chicken is actually cheaper per pound than buying fresh raw chicken to cook at home. Is that the whole of the problem? No - but it is a contributor.
(Though, to be fair, the rotisserie chicken is more healthy than the fried and also sold dirt cheap, and the frozen chicken parts can be pretty cheap, too, especially when on sale).
I’ve got a bunch of 20-something coworkers who know very well that thinner is better than fatter, but they don’t know how to cook. Seriously, I’ve been giving a sort of remedial e-mail course to them on basic thinks like how to make a simple casserole (veg, meat/bean, noodle + cream soup base) because they NEVER learned even something that simple. Their parents raised them on frozen meals and fast food take-out. Yes, they are capable of learning, but when no one in their lives does any cooking whatsoever (I don’t count “put box in microwave, nuke on “high” 6 minutes” as cooking) they don’t know how to cook. We’ve got young cashiers who have to be trained on how to identify basic fruits and vegetables. It’s very sad.
Providing stats will be difficult. I am doing this on my smartphone and I haven’t figured out how to copy and paste yet (sorry–but I am learning).
And again, I heard it on TV some time ago. So it is hard to back it up with cites, or even stats for that matter.
I am going offline for a little while now in any event. While that is happening, and while I meanwhile consider my options, maybe someone else will give some statistics. (As I said, I think it is just common knowledge anyways.)
But you don’t have to discard the rest of the chicken. You need to have a fridge or freezer and the ability to stop after eating only one breast. A whole roast chicken lasts me 5 meals (not sequential). And that’s if “you” happens to be a single person: the same roast chicken lasts my family half a family on any Sunday (9 of us at the table, 2 chickens).
For many people, the issue is in knowing when to stop and being able to do it.
But it is more expensive to eat chicken breast than chicken-flavored ramen.
Didn’t it use to be that poor people were skinny and only ‘rich people’ were fat?