Your Post Office Processing Facility: Your Liver. Your liver is the second-heaviest organ in your body (the largest, your skin, is actually twice as heavy) and is your body’s metabolic machine. Your liver works a lot like an urban postal center, taking in all the incoming mail (in terms of nutrients and toxins), sorting it, detoxifying it, and then shipping it off to different destinations for your body to use as energy.
While the three organs all play different roles, the upshot of their relationship is this: The small intestine initially processes your food, and your omentum helps store it. Inflammation occurs in your small intestine and omentum, but the big battle happens in your liver, where the mother of all inflammatory responses takes place. That’s the one that makes you store fat—and experience the unhealthy effects of it.
FACTOID
Fat is like an organ, but the omentum is the supercharged version. Omentum fat has more blood supply than any other kind of fat and is quickest to mobilize itself to feed the liver.
Yes, we know that in-your-gut physiology isn’t always pretty, but we want you to keep in mind our main gut goal: By understanding how food travels through this leg of your digestive system, you’ll be able to identify the foods that will help you reduce harmful and weight-related inflammation. When you do that, you’ll have signed a digestive peace treaty that can end the war on your waist.
FACTOID
About 10 percent of Americans have fatty livers that are overwhelmed with fat sent from the intestines and omentum for processing. Fatty livers can lead to fibrosis-reduced liver function, and even the serious liver disease cirrhosis over time, although for most folks, you just end up looking like foie gras on the insides.
Gathering Intelligence
They say that a woman thinks with her heart, and a man thinks with his personal periscope, but when it comes to sheer anatomy, the organ closest to your brain isn’t the one that flutters over a midnight serenade or the one that tingles over a lingerie catalog. It’s the one that coils through your gut like a sleeping python.
From a purely physiological standpoint, your small intestine functions as your second brain. It contains more neurons than any organ but your brain (and as many as your spinal cord), and the physical structure of the small bowel most resembles that of the brain. In addition, after your brain, your small intestine experiences the greatest range of emotions—in this case, your feelings manifest themselves in the form of gastrointestinal distress. In your brain, you react to actions: You feel love when your spouse holds your hand, mad when he forgets an anniversary, humiliated when he takes off his shirt at the Bears game and thumps his densely forested chest for a shot at being on SportsCenter. Your small intestine does the same thing. It reacts to foods that enter its pathway, depending on their anti- or proinflammatory effect. Your foods dictate whether your small intestine feels mild annoyance (a little bloating), anger (gas), stubbornness (constipation), or all-out temper tantrums (a thar-she-blows case of diarrhea).
Of course, you’re the one who decides what foods you’ll eat, but your small intestine works like an undercover agent—gathering information about all the nutrients and toxins that enter your body.
Your small intestine feels. Your intestine thinks. And your intestine performs a critical job during digestion: It helps guide you in all of the decisions you make about eating, because it tells you which foods agree with your body and which ones don’t. How does it do that? Through the absorption of those foods. Your small intestine has an absorptive surface area that’s 1,000 times larger than its start-to-end length because of all of the accordion-like nooks, crannies, and folds within it. Those spaces are where your body actually absorbs nutrients. So your intestinal absorption area isn’t just 20 feet long; it’s the equivalent of 20,000 feet long. No wonder you absorb so much of what you eat. When you have inflammation in the wall of your small intestine (through a food allergy or intolerance), it dramatically cuts down on that absorptive surface area—from about 2 million square centimeters to 2,000 square centimeters—because of swelling and poisoning of the functional surface cells. And if the intestine can’t absorb nutrients, you experience an upset stomach and diarrhea.
Why Some People Stall
We’d like to think that our bodies work like cars-press the accelerator to go faster, tap the brakes to slow down. But our body’s metabolic switches don’t quite work that way: We may not gain or lose weight at the rate in which we expect to. When we have inflammation, our bodies are less efficient meaning that we burn more calories-as a way to protect you, even as you gain weight. As we lose weight and decrease inflammation, our bodies go back to being efficient, and we may not burn calories at the proportional rate in which we gained them. So when we eat the right foods and more efficiently metabolize them, weight also may stall temporarily-meaning you still may be heavy, but might not have as many health risks associated with the weight.
While we’re all familiar with those overt, emergency intestinal crises, our intestinal emotions also influence us in ways we don’t normally associate with food. The reason we may feel groggy or have less energy than a drained nine-volt could be because our intestines are trying to tell us we’re choosing the wrong foods. If you pulled out the small intestines of your entire family and laid them on the back deck to compare them (latex gloves, please), you’d see that they all look alike; they’re the classic, wormy tubes that wind throughout your gut. In terms of basic physiology, we all have the same intestines, just as we all have the same basic brain structure. But just as all of our brains don’t function the same way even though we have the same parts, our intestines don’t function the same way either. YOU-reka! Our intestines are as different as our smiles, as our laughs, as our political views, as our fetishes. A particular food can make one person feel energized and make another person feel as lethargic as a rag doll.
FACTOID
You may hear that celebrities get colonics because they seem like some sort of miracle weight-loss cure. Here’s how they work: You get a tube pushed up into your lower intestines (via your back end). You’re infused with a solution, and you roll around to wash out your colon, then the fluid gets sucked out (you’re given coffee, to help you go to the bathroom quickly). The purpose is to cleanse out the toxins and “reboot” your intestines. You’ll produce a lot of waste after a colonic, but the main waste here is of money. Your colon only absorbs water, so there’s no weight-loss benefit from colonics. In fact, you can get the same colon-cleansing and toxin-eliminating effect with a twenty-four-hour fast.
Anatomically, your intestinal wall is Clint Eastwood tough. With more than a trillion bacteria living in your intestines at any given time (most of them helpful, but at least 500 species of which are potentially lethal), your body protects itself with a fortified infrastructure to keep the bacteria out of your bloodstream. But your body—though it relies on that Fort Knox-like wall—has to have a way to give clearance to authorized visitors. That is, it needs to allow nutrients to get through the wall to your bloodstream so you can use food as energy to keep your organs functioning, to go to work, to pry the kid’s fingers from the panicked frog’s leg. (One of the ways this penetration system works is through bile, which tricks the wall’s security so fats can get through to the bloodstream.) This selection of