Monday, August 14, 2006

Stomach Bugs

This weekend, The New York Times Magazine featured an article entitled, “Fat Factors,” suggesting that a previously unconsidered factor may be to be blame for your weight—microogranisms.

The article’s author, Robin Marantz Henig, describes recent research indicating yet another biological theory of weight—we already have about 50 “guilty” obesity genes, some of which regulate appetite, satiety cues, and activity level. But now, scientists are exploring the possibility that intestinal microbes (e.g., bacteria, fungi, etc.) may play a role in how fat you come to be. And, lest you have any lingering doubts about an uncertain future, Jeffrey Gordon, the director of the Center for Genome Sciences at Washington University, informs us: “‘Microbes colonize our body surfaces from the moment of our birth. . . . They are with us throughout our lives, and at the moment of our death they consume us.’”

According to Henig’s article, microbes (microflora) accomplish a multitude of gastro-intestinal tasks, including the production of vitamins and enzymes, as well as the facilitation of digestion. Henig writes that they “help extract calories from the food we eat and help store those calories in fat cells for later use—which gives them, in effect a role in determining whether our diets will make us fat or thin.” Thus, my 450-calorie meal may be different than yours. It’s possible that I will extract and store 400 of these calories, you only 300, based on varying levels of intestinal microbes, thus complicating the classic calories-in-versus-out method of weight-loss or -maintenance. And, the formulaic 3,500-calorie reduction requisite for a one-pound weight-loss? Again, not so rigid when microbes are involved.

The Times article details animal studies, suggesting that bacterial microflora and/or exposure to certain viruses (“infectobesity”) lead to increased incidence of obesity. In other words, catching a virus can make you fat. Correlational studies in humans seem to support this notion—those with certain viral antibodies are more likely to be obese. Viruses may lead to increases in fat-cell counts and size or may toy with the brain’s satiety center.

While data are still preliminary, researchers are already toying with antibody tests (documenting exposure to one of the implicated viruses), and as you might imagine, antiviral-drug administration looms in the horizon. What I find most interesting about this report are its psychological and sociocultural correlates. Here, we have yet another biological theory of weight (the existence of obesity genes, preceding it) and yet, we still hold strong to the belief that obesity is a psychological condition, an individual failure of will-power, conviction, and self-regard, when in fact, there are plenty of “overweight” people who eat no more than their thinner counterparts. More and more, research is debunking that myth. Henig details an interesting example discussed by Rudolph Leibel, a Columbia University obesity researcher, “. . . if you take two nonobese people of the same weight, they will require different amounts of food depending on whether or not they were once obese. . . formerly fat people need to eat less than never-fat people to maintain the exact same weight.” The possibility of a microbial factor in the incidence of obesity lends weight to the notion that losing weight may be more of an uphill battle than previously thought.

And there seems to be good reason for this. Transport overweight people back in time, and they’re likely to fare better than those who are thin. As Henig notes, the “thrifty-genotype” hypothesis of weight suggests that historically, there was an evolutionary advantage to packing on the pounds. Now, technologically advanced beyond famine and draught, there’s no such need for biological stores, but let’s not underestimate the power of context—put obese people in another time and another place, and they’re royalty, exalted for their natural inclination toward getting fat and “keeping it on.” They survive, while the skinny perish, somehow unable (or not having the discipline) to eat enough.

10 comments:

ps22 said...

I approach these studies with caution. Our society is so caught up with finding the specific cause, the one to blame, the one point where things all fell apart...all as a means of avoiding the inevitable truth that life is full of complex problems and complications and it takes a lot of work to fix them. My point is that while these studies provide important information, they don't change the fact that our society has fueled misconceptions about body perception, weight/food, etc. (as Dr. S has so appropriately pointed out). But how often do we see major funding dollars going to studies that explore those issues? Biology always wins out because people want a quick fix (or a quick reason why they can't fix it).

PalmTreeChick said...

Interesting point PS222. Yeah, everyone is looking for something else to blame, and yes, sometimes there are legit medical causes for obesity, (thyroid, etc.) but lots of time it's just taking in more calories than you burn.

Besides, I don't like to think about yucky bugs and stuff in my body, even know I know there there somewhere. yuck!

ps22 said...

PTC - I do agree about legit medical causes for obesity. But I'm not just talking about obesity. More so, I'm referring to the "sickness" of fixation on body, weight, food, and looks...no matter what your size. All the medical studies in the world won't change that problem.

PalmTreeChick said...

YES, you are correct. I misread. I'm a little sleepy today. Sorry, ps222.

the only thing that might change that problem would be getting rid of tvs, magazine, etc.

BigAssBelle said...

Interesting study. I'm reminded of the doc who discovered the bacteria that now seems to be the primary cause of ulcers. For all of my young life, people with ulcers talked about stress and having to avoid spicy foods, drink milk, that sort of thing. Now people with ulcers take an antibiotic and are, most of the time, actually cured.

I don't doubt there is way more to this food/eating/addiction/weight thing than we now know. I am always excited to read new research in the area and wish I could wait around ;-) until the cure is found. Alas, I must save my own life now and the only present day way to do that I know of is eating sanely and exercising.

Love your stuff ~ definitely the makings of a book here.

lynette

pinkcat said...

As a formerly obese person, I once weighed 249 lbs and am 5 ft 5 in, I know that I have to limit my food strictly to be very thin. (I've given up that goal because I love food more than I love a size 2 body). It is so freeing to know that it is biology not will power or a personal failure that makes me fatter than society thinks I should be. (Okay so I do buy into this whole thin thing to a certain extent).

I don't believe that because biology is making us fatter that we will all just sit back and say can't lose it because I have no control over my biology. Once I realized that it was biology it made me see how difficult it is to lose weight and cut myself some slack about it. It helps because I know what won't work when it comes to losing weight. Just excercise won't do it and cutting way back on calories will just make me fatter in the end. Knowing that I need 15% less calories than an always thin person to maintain a certain weight really helps. I can adjust intake or excercise to account for this. I believe that this can make the whole weight thing much less frustrating.

Haley-O said...

Ugh. Another day another study. It's all niether here nor there. Everyone's looking for new answers because what is perhaps the most obvious one just isn't good/scientific/sensational enough: a culture that fosters sitting on the couch, isolation, sitting in an office, fast food. ;) Our culture just has the biggest ego and won't take responsibility! ;)

littlem said...

"Society is so caught up with finding the specific cause, the one to blame, the one point where things all fell apart...all as a means of avoiding the inevitable truth that life is full of complex problems and complications"

ps22, IMO you really nailed this. The article said there are at LEAST 50 factors involved in weight loss. Our society has an obsession with ignoring the subtle in favor of the black-white analysis, and IMO they are NEVER going to find a method that works the SAME WAY for EVERY SINGLE PERSON, because everyone is different.

I think Pinkcat is also right about how knowing what you need for your own body, and focusing on making that body work and making that body stronger and healthier, instead of obsessively comparing and comparing and comparing and COMPARING ourselves to other people -- especially since we're NOT all the same -- makes a huge difference.

I know I personally struggle with it because I'm always OK until I think that someone ELSE -- a boss, a boyfriend -- is comparing me unfavorably with someone else. Dr. Stacey, any tips on how to deal with that part?

drstaceyny said...

ps--true, studies can seem reductive. Your comment made me think of an interesting discrepancy--insurance companies are all over obesity, while only 10 states (as far as I'm aware) mandate e.d. treatment. Truth is, health consequences for anorexia, for example, are much more serious than then are for being overweight.

ptc--yeah, kinda gross to think about. . .

bab--interesting analagy w/the ulcer. It seems like you have a good plan for yourself. Thanks for reading!

pc--I agree--an understanding of biological factors helps validate the struggle.

haley--good point--in fact, research suggests that our sedentary status (as a culture) is the biggest factor to blame for health problems (not weight!)

lm--good question. At the risk of sounding trite, I'd say do your best to surround yourself with ppl who don't compare you with others, who value all that you have to offer outside your appearance. If people do offer these types of judgments, express your feelings abt them (it's not ok!), and challenge yourself to understand why they affect you to the extent that they do. That's easy enough, right? ; )

littlem said...

"That's easy enough, right? ; ) "

LOLOLOLOL

"challenge yourself to understand why they affect you to the extent that they do"

Well, if it's a boss, it's because I'm afraid I'm going to get fired and replaced with someone prettier and thinner (yes, it's happened) and if it's a boyfriend, it's because I'm afraid I'm going to get broken up with and replaced with someone prettier and thinner (ditto).

So, aside of looking closely at choices in bosses and boyfriends -- and everyone's choices about things are limited to some extent, you can only choose from a) what's in front of you and b) who will choose you back, at least in those circumstances -- I'm really not sure what additional challenge there is that I could personally meet.