Or, why “just take in fewer calories than you burn” is not quite that simple.
Katsyuri sent in this Newsweek article, discussing how intestinal bacteria may affect the number of calories the body is able to absorb. More efficient bacteria = more calories absorbed = more “calories in” than average.
The calories that count are those extracted by your digestive enzymes and—as more and more research is showing—the trillions of bacteria in your intestine. People whose gut bacteria are better at digesting fats and carbs than their neighbor’s will absorb all 1,500 calories in a Friendly’s Ultimate Grilled Cheese BurgerMelt, while the neighbor will absorb fewer. So even in people with identical metabolisms, the effects of eating identical foods can be different.
The bacteria-made-me-fat idea has been gathering steam since 2006. In that year, Jeffrey Gordon of Washington University and colleagues reported in a paper in Nature that obese mice and slim mice have different populations of gut bacteria. Crucially, they showed that the bacteria caused obesity, rather than obesity producing a specific mix of bacteria.
There’s also a slideshow that touches on the connection between underprivileged communities and the prevalence of fast and processed foods (along with pictures of sad fat people… but they do have heads). Here’s Katsyuri’s disclaimer:
It’s still mainly the same old tripe about exercise and calories and that “Obesity Epidemic”, but at least it doesn’t COMPLETELY blame bigger people for everything.
The article does have some more interesting tidbits:
A study published in April… found that Japanese people harbor gut bacteria that digest nori—the seaweed in sushi—but westerners do not, probably because of the Japanese diet (lots of fish and thus marine bacteria, which digest nori). That suggests that “what you eat is proving to be one of the major determinants of…the community of bacteria living in your intestine.”
I wouldn’t be surprised to see people with nefarious motives say to people trying to lose weight, ‘you must have the wrong bacteria; I have something that will help you.’
The idea here is that gut bacteria interact with intestinal cells in a way that causes them to secrete cytokines, molecules that can cause low-grade inflammation. This inflammation can, in turn, trigger insulin resistance (the mark of type 2 diabetes) and increased appetite, which is an effective way to put on weight.
As scientists work out the details by which out gut bacteria make us fat, health mandarins need to look beyond the simplistic calories in/calories out mantra for explanations of the obesity epidemic.
So what do you think: is this kind of science—shifting the blame away from fat people—a step in the right direction? Or is the focus still in the wrong place?
[Note: The title of this post is a play on an Eric Cartman quote.]
Posted by mo pie