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Comment by tjic | Hacker News Reader

There may be more to the methodology than presented, but from what I read, it stinks. They merely looked at height, weight, and location without controlling for income.

Wealthier people are in better shape and weigh less (for the first time in history we live in a society in which poor people still earn enough money to become obese!).

More walkable areas may be more desirable, and may therefore have higher prices, and may therefore only be available to wealthier (and thinner) people.

The article doesn't establish causality at all.

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The study is linked to in the second paragraph. It appeared in what seems to be a reputable, peer-reviewed journal and controls for socioeconomic status.

I see this all the time online: a study is published, and a chorus of commenters echo "correlation isn't causation" without actually reading the study and seeing that these other factors have been accounted for.

There are plenty of things wrong with science reporting, but when many readers are apparently too lazy to exert the minimal effort to verify that their misgivings were indeed addressed by the researchers, one can't exclusively fault the media.

In passing, while playing with Google Trends, there seems to be a long term inverse correlation between media coverage and search volume for terms such as 'study' and 'research', as well as for the term 'statistics'. http://www.google.com/trends?q=statistics,+study,+research&#...

The annual cycle seems to correlate strongly with college schedules :)

I have to disagree with both of you. The original criticism was incorrect, because this study does control for income and other socioeconomic stuff. But "correlation isn't causation" is still a valid criticism of this study. To prove causation you would have to have some random effect controlling where people live.

Just because it's peer-reviewed doesn't mean the article proves what it claims to. Unless you have a natural experiment it's hard to prove causation in situations like these. So you get a lot of published research that just proves correlation.

You merely read a blog post about the study. The study itself is linked in the second paragraph. Here:http://www.ajpm-online.net/webfiles/images/journals/amepre/A...

If you had bothered to click on the link to the original study, you would have seen this in the second paragraph (the "Methods" section):

"Linear regressions of BMI and logistic regressions of overweight and obesity include controls for individual-level age and neighborhood-level racial/ethnic composition, median age of residents, and median family income."

Poor people become obese because cost of food does not depend on calories, or rather is inversely related to calories. The cheapest foods tend to be the most processed, less nutricious, but very calorie laden.

So it's not exactly that they "still earn enough money" to become obese, it's that somehow the food supply has been inverted so everyone can afford calories but not so many can afford healthy food.

Besides that, as a counter argument to your hypothesis, wouldn't inner city neighborhoods be old and walkable? In that case, your argument that they are more healthy because they are inhabited by richer people doesn't seem to fly.

While this is true in general, it is still possible to eat a balanced, healthy diet for very little money. That said, it requires a lot of discipline and a somewhat sophisticated understanding of nutrition. Still, my wife and I managed to get by on $20-30/week for combined groceries for about a year (we're in AZ, and being vegetarian helps keep costs down), but still managed to eat well.

Holy crap. Do you mind giving us a rundown of what you ate in a typical week? I'm really curious.

Some cheap and healthy things: Oat meal, beans, tea / water, fruits of the season, yoghurt, rice, pasta, potatoes, sweet potatoes, cabbage.

I can easily imagine eating for around 2 Euro a day or even less. It just would not be as much fun. So I get around with 5 to 7 Euro, that allows me to add delicious ham and some other meat to my diet in small portions.

eru nailed it. We lived off bulk everything -- oatmeal, rice, beans. For fresh food, we got cheap veggies with lots of nutrition; greens tend to be the best bang for the buck, but also bags of carrots, beets, and such. For protein, it was all about tofu, eggs, milk, yogurt and nuts (mostly peanuts, soy nuts or pepitas, which are much cheaper than tree nuts). For beverages, bulk tea is absolutely the way to go, at just a few cents per cup.

Food prices have really shot up since 2006 though; in particular, bulk beans have almost doubled. Still, I think it would be possible to eat the same diet today for around $35/week for a couple.

It's just laziness, rice and beans are still cheap and work fine for huge parts of the world. Being poor in America is no excuse to be fat.

Laziness? Is that based on opinion or data? This is an unbiased question. I am further interested in how widespread this sentiment is.

I heard a story about a McDonald's closing in a poor area. There are at least two effects of this, the second of which was quite surprising: 1. McD, a source of high-fat food, leaves the area, and subsequently people need to find alternative food; 2. McD, a source of cheap food, leaves the area, and subsequently people have trouble affording food.

Apparently McD's distribution chain is so efficient, that their presence resulted in wider access to food. I say nothing about nutrition, jobs, or anything else. Just food that fills your stomach. It seems like nothing is that simple enough to summarize in a single sentence. Doing so is likely overestimating of your grasp of the situation. But perhaps it is indeed just laziness.

Also see: http://news.ycombinator.com/item?id=643999

I don't know of a study that makes the claim, but I can go to the grocery store and buy really cheap food that's not bad for me. It takes more work to prepare than hitting a preset on the microwave or going to a drive-thru, but it's cheap and will keep you healthy.

(I say this as I'm about to re-heat some left over spanish rice that I made last night. It cost almost nothing to make.)

Perhaps you should read "Why it's expensive to be poor." http://news.ycombinator.com/item?id=619110

I recently learned the great utility of beans and I asked why they aren't pouring over the streets. Apparently: culture, agriculture, and subsidies. A culmination of broken links.

Why on earth aren't beans subsidized instead of corn? Among other things, this would cut down immensely on the amount of fertilizer consumed per year.

My guess: Grain farmers have the better lobby.

Anyway, beans don't need a subsidy.

Characterizing the problem as one of "just laziness" is intellectual laziness. For one thing, the environment is dramatically different. People have an easier time sticking to rice and beans when that's pretty much all there is. In America, unhealthy food is not only more accessable but heavily marketed. You can't expect people to make similar descisions on average in such different circumstances.

If poor people are eating unhealthy food because of marketing it is still laziness. Take the time to find out what's good for you, it's not hard.

My point is that no one can honestly say that they are fat because they can't afford good food. There are tons of excuses, but it comes down to personal responsibility.

I'm not talking about excuses, I'm talking about your expectations. You're holding people born in America to a higher standard of discipline than those born elsewhere, and poor Americans to a higher standard than rich Americans.

From the article

> Sociodemographic Measures > Driver license data provide individual-level age and gender. Additional block-group census variables include neighborhood racial/ethnic composition (the proportion of the block group that is Hispanic, African American, Hawaiian/ Pacific Islander, and Asian); median family income; and the median age of individuals in the block group.

....

> Our conclusions are tempered by several study limitations. First, self-reported BMI was used, which can underestimate true BMI. Second, few individual measures were available, thus excluding other potential controls (e.g., number of years in the neighborhood, individual racial/ethnic status, commute distance). Third, the sample is based on one (albeit large) county. Finally, because the analysis is cross-sectional, it is possible that those who value healthy weight may move to walkable neighborhoods. One study of longitudinal data on adolescent BMI demonstrates that cross-sectional relationships similar to those found in the present study did not translate into longitudinal ones.45 Accordingly, future work should assess potential selection effects using longitudinal data on adults.

http://www.ajpm-online.net/webfiles/images/journals/amepre/A...

I live in a very walkable city -- in fact, finding parking is quite inconvenient. It's actually much easier (and healthier) for me to walk a mile to wherever I need to go. In this situation (as I'm sure is true with any downtown area), it is not hard to imagine that the conclusions of the study are sound. Of course, causality is always impossible to establish in sociological studies like this.

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