Here’s how they all work together: Ghrelin works in the short term, sending out those hunger signals twice an hour. Leptin, on the other hand, works in the long term, so if you can get your leptin levels high, you’ll have a greater ability to keep your hunger and appetite in check. Isn’t that great? Leptin can outrank ghrelin—to keep you from feeling like feasting on anything short of fingernails every few minutes. If you focus on ways to influence your leptin levels, and, more important, leptin effects (through leptin sensitivity), your brain (through CART) will help control your hunger.
Sometimes, it may seem like we don’t have much control over the chemical reactions taking place within our arteries or inside our brains. But just as you can control things like cholesterol and blood pressure by changing the foods you eat or altering your behaviors, you can also control the satiety center of your brain. How? Through your choice of foods.
Figure 2.3 In a Jam The satiety center is waiting to be turned off by NPY or stimulated by CART. Whichever fills up the receptor docks first is what controls whether you want to eat more or not. In turn, these two proteins are influenced by lack of water, sleep, and even sex. They’re also influenced by ghrelin coming from your stomach, which stimulates NPY so you get hungry, and leptin from your fat, which is further stimulated by a chemical called CCK, released from your intestines after a meal.
At least as far as your body is concerned, foods are drugs; they’re foreign substances that come in and switch around all those natural chemical processes going about their business within your body. When your body receives foods, different chemical reactions take place, and messages get sent throughout your system—turning on some things, turning off others. While your body internally gives orders, you set the tone and direction of those orders through the food you’re feeding it. Eat the right foods (like nuts), and your hormones will keep you feeling satisfied. But eat the wrong foods (like simple sugars), and you’ll cause your body to go haywire hormonally, and that ends up with one result: the next notch in your belt.
A major gang leader against your body is fructose, found in high-fructose corn syrup (HFCS), a sweetener in many processed foods. Here’s how it works: YOU-reka! When you eat calories from healthy sources, they turn off your desire to eat by inhibiting production of NPY or by producing more CART. But fructose in the HFCS, which sweetens our soft drinks and salad dressings, isn’t seen by your brain as a regular food.
Because your brain doesn’t see any of the fructose in the thousands of HFCS-containing foods as excess calories or as NPY suppressants, your body wants you to keep eating (which means that even low-fat foods can have extremely bad consequences, calorie- and appetite-wise). Americans have gone from eating no pounds of this stuff per person in 1960 to eating more than sixty-three pounds of it every year (that’s 128,000 calories). That’s a contributor to weight gain, since the fructose in HFCS doesn’t turn off your hunger signals. Foods with fructose—which may in fact be labeled as low-fat—make you both hungry and unable to shut off your appetite. They are also rich sources of calories: the perfect storm of weight gain. So you constantly get the signal that you’re hungry, even after you’ve jammed your gut with two baskets of calorie-laden, fructose-loaded biscuits.
YOU TIPS!
Get Over Sticker Shock. You should read food labels as actively as you read the stock ticker or the horoscopes. Don’t eat foods that have any of the following listed as one of the first five ingredients:
Simple sugars
Enriched, bleached, or refined flour (this means it’s stripped of its nutrients)
HFCS (high-fructose corn syrup-a four-letter word).
Putting them into your body is like dunking your cell phone in a glass of water. It’ll cause your system to short out your hormones and send your body confusing messages about eating. Today’s yearly per capita consumption of sugar is 150 pounds, compared to 7.5 pounds consumed on average in the year 1700. That’s twenty times as much! When typical slightly overweight people eat sugar, they on average store 5 percent as ready energy to use later, metabolize 60 percent, and store a whopping 35 percent as fat that can be converted to energy later. Any guess as to where 50 percent of the sugar we consume comes from? HFCS in fat-free foods like salad dressings and regular soft drinks.
Choose Unsaturated over Saturated. Meals high in saturated fat (that’s one of the aging fats) produce lower levels of leptin than low-fat meals with the exact same calories. That indicates you can increase your satiety and decrease hunger levels by avoiding saturated fats found in such sources as high-fat meats (like sausage), baked goods, and whole-milk dairy products.
Don’t Confuse Thirst with Hunger. The reason some people eat is because their satiety centers are begging for attention. But sometimes, those appetite centers want things to quench thirst, not to fill the stomach. Thirst could be caused by hormones in the gut, or it could be a chemical response to eating; eating food increases the thickness of your blood, and your body senses the need to dilute it. A great way to counteract your hormonal reaction to food is to make sure that your response to thirst activation doesn’t contain unnecessary, empty calories-like the ones in soft drinks or alcohol. Your thirst center doesn’t care whether it’s getting zero-calorie water or a mega-calorie frap. YOU-reka! When you feel hungry, drink a glass or two of water first, to see if that’s really what your body wants.
Avoid the Alcohol Binge. For weight loss, avoid drinking excessive alcohol-not solely because of its own calories, but also because of the calories it inspires you to consume later. Alcohol lowers your inhibition, so you end up feeling like you can eat anything and everything you see. Limiting yourself to one alcoholic drink a day has a protective effect on your arteries but could still cost you pounds, since it inhibits leptin.
Watch Your Carbs. Eating a super-high-carb diet increases NPY, which makes you hungry, so you should ensure that less than 50 percent of your diet comes from carbohydrates. Make sure that most of your carbs are complex, such as whole grains and vegetables.
Stay-Va-Va-Va-Voom-Satisfied. In any waist management plan, you can stay satisfied. Not in the form of a dripping double cheeseburger but in the form of safe, healthy, monogamous sex. Sex and hunger are regulated through the brain chemical NPY. Some have observed that having healthy sex could help you control your food intake; by satisfying one appetite center, you seem to satisfy the other.
Manage Your Hormonal Surges. There will be times when you can’t always control your hormone levels; when ghrelin outslugs your leptin, and you feel hungrier than a lion on a bug-only diet. Develop a list of emergency foods to satisfy you when cravings get the best of you-things like V8 juice, a handful of nuts, pieces of fruit, cut-up vegetables, or even a little guacamole.
Chapter 3
Eater’s Digest
How Food Travels through Your Body
Diet Myths
Fat turns to fat, protein turns to muscle, and carbs turn to energy.
The fullness of your stomach is what tells you to stop eating.
Sugar gives you an instant