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Obesity Contagious?
An anonymous reader writes "University of Wisconsin-Madison researchers have found that certain human viruses may cause obesity, and by extension make being severely overweight a contagious condition. 'It makes people feel more comfortable to think that obesity stems from lack of control,' the lead researcher says. 'It's a big mental leap to think you can catch obesity.' But other diseases once chalked up to environmental factors, like stomach ulcers, are now known to stem from infectious agents."
If you eat less than your body requires, by definition, you die. Being able to eat less and lose weight instead of starving while fat depends on the ability to get blood sugar out of fat, which is compromised in people with a number of conditions. It also depends on having a low-calorie source of non-energy nutrients, which is often expensive. It also depends on being able to maintain a reasonable blood sugar level without more energy being taken out as fat.
For people without a medical condition that causes obesity, it is possible to take in fewer calories and run off of fat instead. But there are a number of medical conditions which can interfere with this process, which depends on a non-trivial cascade of signals between different organs (something has to detect that your blood sugar is low; it has to release a hormone in response; the fat cells have to respond to this hormone; they have to produce sugar from fat; the fat cells have to stop pulling sugar out of the bloodstream and storing the energy). This research found that some people are obese because of a particular virus. Of course, most of the people they looked at probably just eat too much, but not everybody.
It's odd that the idea that a virus can contribute to, or even be a causation of obesity is so poorly received here. Bear in mind that these are experiments on test animals on a controlled diet, not some survey of McDonalds patrons.
Perhaps because the linked article was a blog...
Study on rhesus monkeys and marmosets.
"In study 1, we observed spontaneously occurring Ad-36 antibodies in 15 male rhesus monkeys, and a significant longitudinal association of positive antibody status with weight gain and plasma cholesterol lowering during the 18 mo after viral antibody appearance. In study 2, which was a randomized controlled experiment, three male marmosets inoculated with Ad-36 had a threefold body weight gain, a greater fat gain and lower serum cholesterol relative to baseline (P 0.05) than three uninfected controls at 28 wk postinoculation. These studies illustrate that the adiposity-promoting effect of Ad-36 occurs in two nonhuman primate species and demonstrates the usefulness of nonhuman primates for further evaluation of Ad-36-induced adiposity."
Not every argument requires reduction to absurdity.