Correlation =/= causation. So many leaps are being made here.
> One study of 60 healthy young adults (in their 20s and 30s) found that the fatter members of the group had significantly lower gray-matter densities in several brain regions, including those involved in the perception of taste and the regulation of eating behavior.
Maybe the lower gray-matter density, particularly in the "perception of taste and the regulation of eating behavior" areas, predisposes them to being overweight, rather than the extra weight causing brain shrinkage. You'd have to do a longitudinal study to be able to make a case for causation...
Yea, the conclusion is overly simplified here. I think it's safe to say not exercising and not eating well is generally bad for your entire well being, not just your brain and weight.
Just want to add that I much prefer "=/=" rather than "!=" when expressing an inequality.. I don't like the latter used in this context. I might totally wrong here, but I always something like "correlation != causation" as a test, not a statement - it could be true or false!
"Whatever the causes, the implications are grave. In the United States today, around one-third of adults are obese. At the same time, dementia is already one of the most costly and devastating health problems of old age. The possibility that obesity today will lead to higher rates of dementia in the future is, therefore, deeply alarming."
Well, if you are fat enough for the average american to notice you can expect a reduced lifespan. If you are slightly overweight relative to BMI charts you actually have a longer life expenctancy. (http://en.wikipedia.org/wiki/File:WikiRRM.jpg)
It's still relative but when you tip 40+ BMI you still have a significantly shorter life expectancy.
On average, obesity reduces life expectancy by six to seven years:[2][27] a BMI of 30–35 reduces life expectancy by two to four years,[21] while severe obesity (BMI > 40) reduces life expectancy by 10 years.[21](http://en.wikipedia.org/wiki/Obesity)
PS: I have a BMI of 34 so I want to know just how bad it can get if I let myself go any further. There is a lot of misinformation out there but being overweight has real negative effects on your heath.
The article is not just saying fat != healthy. There are some good comments to takeaway about how fat affects the brain, e.g.:
" Fat cells also secrete substances that cause inflammation; chronic inflammation of the brain, which is often found in the obese, impairs learning and memory and is also a feature of Alzheimer’s."
I don't like the causal relationship expressed in the title of this article. What the data they describe in the article suggests is that increased risks for dementia and obesity are linked. But the title has the typical, "If you're not working out you're HURTING YOUR BRAIN." That, it seems, is not yet researched enough to be conclusive (nor is it really germane to the article).
Yet another case of "Good Article, Bad Headline."
I hope this isn't another excuse for thin people to lord their genetic predispositions and life choices over thick people. That's very tiresome.
Yes, being morbidly obese isn't healthy, but I feel obligated to point out that being underweight is generally as bad medically as being obese, yet due to society's standard of beauty trending towards people who are practically skeletal, you don't see that mentioned nearly as much.
Yes, but the underweight people tend to be certain groups of children's role models. While we shouldn't be encouraging our children to be obese, we certainly also shouldn't be pointing them towards models who are clearly anorexic and consider them to be our standard of beauty.
"Clearly anorexic" models haven't really been "in" since the early 90s, and even then most of them weren't anorexic, just skinny. There has been an interesting divergence between "fashion model" and "sex symbol" since the days of the "supermodel" (a term one rarely hears nowadays), and today's sex symbols are back to mostly being actresses and singers. This is largely because the body types which make clothes look best are not really the body types than men are most attracted to.
What was my point? Oh yes, there are very few genuinely underweight people seen as role models. Keira Knightley, perhaps.
Some problems associated with being underweight (I was very underweight when younger) I am aware of are:
- susceptible to illness/disease
- poor metabolism
- bad blood flow
- tiredness
The problems are different, definitely, but no less problematic.
I would argue the higher number of people dying of obesity is purely down to the higher number of obese people (compared to dangerously underweight people)
So if you are not tired not weak and almost never sick but technically underweight you don't have to worry? How can you determine poor metabolism and bad blood flow?
Who says that being underweight presents less consequences than being even just overweight? I had the idea that being slightly overweight actually increases the life expectancy. A quick search gave me this:
Err... no. If you're underweight, you are undernourished. If you're undernourished, you lack the correct amounts of at least some nutrients that are required for proper bodily function.
Being underweight can cause the following issues (and others): a severely weakened immune system, increased chance of early-onset osteoperosis (sort of similar to the increased chance of early-onset dementia), heart irregularities which can lead to serious heart damage, and anemia.
Edit: Now that you've edited your post to include the dangerous components of being underweight, I don't really see how you can support your conclusion.
"Flegal et al., however, found that the mortality rate for individuals who are classified as overweight (BMI 25 to 30) may actually be lower than for those with an "ideal" weight (BMI 18.5 to 25).[12][13]."
> One study of 60 healthy young adults (in their 20s and 30s) found that the fatter members of the group had significantly lower gray-matter densities in several brain regions, including those involved in the perception of taste and the regulation of eating behavior.
Maybe the lower gray-matter density, particularly in the "perception of taste and the regulation of eating behavior" areas, predisposes them to being overweight, rather than the extra weight causing brain shrinkage. You'd have to do a longitudinal study to be able to make a case for causation...