YOU on a diet --- more from the book

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Belly Up Not all fat is skin-deep. Deep down under your muscles, the omentum drapes off the stomach like stockings on a hanger. As we store fat, the omentum wraps around to give us the dreaded beer belly. Toxic Dump All the nutrients we absorb through the intestines pass through the liver via the portal vein. Excess fat and inflammatory chemicals stored in the omentum can dump directly into

the liver as well, which can start a cascade of toxic protein release into the body. Infected and Inflated While it's true that everything from your hair to that ankle tattoo technically belongs to you, the truth is that only 10 percent ofthe cells on and in your body are actually yours. The rest are microbes living on your skin and in your orifices (pleasant visual, eh?), and especially in your gut. Those gut-residing microbes provide the enzymes you need to digest the fiber in fruits and vegetables that would otherwise pass through your system without being absorbed (pleasant visual number two). That's right. Without the bacteria and viruses in your gut, the food-label waring about 100 calories per bite would be a gross exaggeration. Specifically, mice raised without exposure to any germs have 60 percent less body fat than ordinary mice, even though they eat 30

percent more food. More intriguingly, common gut bacteria inhibit proteins that normally prevent the body from depositing fat, so infected mice have more belly fat. So what do a few blubbery mice have to do with obesity in humans? It turns out that people infected with a specific chicken virus in India carry an extra 33 pounds of fat compared with noninfected humans. More important, they have lower choesterol and triglyceride levels-just opposite of what we expect with weight gain. Why? Perhaps because the germs in the gut also diges cholesterol, so that less of it is absorbed. In an American study, the virus was found in 30 percent of obese subjects compared to only 11 percent of leaner people, and the folks who had the virus weighed significantly more thanuninfeced people. (And when twins with only one infected sibling are examined, the infected twin has 2 percent more body fat, despite having the same

genes>) Finally, we know that fat cells and our immune system, possibly explaining why obesity causes an inflammatory response and leads to elevated C-reactive protein (a marker of inflammation) . So how do you tell if you have a germ civil war insiide you that's causing obesity? If your cholesterol and triglyceride levels are low and your C-reactive protein lievel is elevated, it might be worth testing yourself; Obetech (www.obesityvirus. com) makes a kit. This might reduce your guilt level, but since science is still gathering data and a cure is still lacking, you will still need to focus on other approaches. At least for now anyway. Help on the Horizon "Fat-free" can refer to marathoners and teen pop stars, but when you see it referring to

food, you have to be skeptical. That's because either it tastes like a shoe box or it can be loadede withlots of sugar to compensate for fat-making that "fat-free" food more dangerous than a slowpoke in the passing lane. One goal for food manufacturers is to make foods that allow eaters to have the best of both worlds: great-tasting food that doesn't have waist-expanding ingredients. One such substance that mayeventually change the way we eat is called Z-trim-it's a natural, zero-calorie fat substitute that's made from the fiber of such ingredients as oats, soy, rice, and barley. While there's no clinical data showing its effeciveness in weight loss, there's some evidence to suggesst it can be used to cut the amount of fat usually used in a meal by 25 percent to 50 percent. The resulting food has all the "taste" benefits of fat (better taste, more creaminess, better mouth-feel) without the caloric load. Z-trim, which you can use

with your own recipes, might also inhibit the hunger-inducing ghrelin because of its fiber content. The downside seems to be that by adding Z-trim, you also lose the benefit of the healthy oils in the food. Our tasters reported that foods with Z-trim had all the flavor of fuu-fat food, and that's enout to make us hopeful that nonfat won't always have to mean high-sugar or no taste. Party Over Foods entering the liver can stimulate either proteins (NF-kappa that act like drunk frat boys and cause inflammation or soothing receptors (PPAR) that put out the fires. Even if you eat too much, if the PPARs are running the show, the negatiove effects are far less. Weird Causes of Obesity Most people assume that being overweight means one of two things: that you eat too much or move too

little. But some research suggest that overeating and inactivity shouldn't be the only things taking the blame for our moon-sized waist circumferences. Studies show that other explanations for obesity include things like-get this- what you stick under your armpits and the age of your mom when she gave birth. Here are some of the more unusual things theorized to be related to obesity: Deordorants: Some deordorants contain chemicals that can disrupt your normal metabolism, making you more likely to gain weight. While we don't recommend ditching the deodorant and caring off elevator mates, you should avoid deodorants that contain the ingredient aluminum or sprays with polychlorobiphenols . The temperature: Air conditioning in the summer and heating in the winter may make you less cranky, but thye also may make you

fatter, If you're in a cold room, for example, your body has to do more metabolic work to bring your temperature to normal (same for a warm room)-thus increasing your metabolism. You can increase your calore-burning motors simply by lowering the temperature in your house during the winter or raising it in the summer. Stopping Smoking: We recommend cigarettes about as much aswe recommend DIY vasectomies, but nicotine can be a powerful weapon in the fight against fat. See our take on nicotine on pace 324. Your mom: Studies show that the older your mom was when she gave birth, the more likely you are to be fatter. While there's nothing you can do to change your family history, having a mom who was older at the time of your birth means you need to be more vigilant about watching your waist. Your mate: Studies show that fatter people tend to choose fat mates, and that increases the odds that you'll produce an even fatter child. We're not in the matchmaking business, but it's worth noting that the best place to meet a mate isn't at the burger joint. Stress Mess The cycle of stress affects weight by increasing hormones above normal levels, resulting in hunger and fat deposition, which causes inflammation, which causes more stress, and off we go.