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If you're determined to lose weight, but find yourself giving in to an irresistible urge to raid the refrigerator, it's probably not a lack of willpower that's sabotaging your efforts. Scientists recently identified a new hormone called ghrelin (sounds suspiciously like "gremlin") that fires up our appetite when our stomachs are empty and actually drives us to eat-eat-eat!
Researchers stumbled on the hormone's appetite-stimulating properties in late 2000 while evaluating the hormone levels of obese patients who had lost weight. In this study, ghrelin spiked before meals, then plunged after the study subjects ate, suggesting that ghrelin triggers ordinary mealtime hunger, says David E. Cummings, M.D., associate professor of medicine at the University of Washington in Seattle. "Ghrelin levels were higher at all time points throughout the day and night in those who had lost weight on low-calorie diets, an indication that a rise in ghrelin is one of the tools the body uses to fight against weight loss," he explains.
An equal-opportunity gremlin
While ghrelin appears to rise no matter how much you weigh when you begin dieting or what method you use to lose weight, researchers measured some of the highest levels in people with anorexia nervosa, says Cummings. Apparently the spike in ghrelin represents the body's attempt to fight the life-threatening weight loss that results from psychological problems, he adds.
By way of contrast, ghrelin levels "were profoundly suppressed in people who had lost massive amounts of weight after gastric bypass surgery," says Cummings. "This suggests that at least some of the weight loss typically achieved with this procedure may arise because ghrelin production is silenced."
Researchers theorize it's a rise in ghrein levels and the associated drive to eat that makes long-term weight loss so hard to achieve: When we restrict calories, ghrelin jumps in and encourages us to eat. With an appetite-boosting hormone like this coursing through our bodies, it's no wonder we binge when we undereat!
Defending the hormone from hell
Ghrelin may have been helpful in the feast-or-famine days. According to scientists, the hormone was probably Mother Nature's way of prompting us to eat when food was only occasionally abundant so we could survive during the next famine. Today, with fast food around every corner, we hardly need another incentive to eat! (Although we have to admit it is nice to finally be able to partially explain those occasional dietary lapses by something besides our lack of willpower.) You know that time you skipped meals to fit into your party dress or bikini -- then got so hungry you ate the whole (cake, pie, enchilada)? It wasn't your fault -- honest. Chrelin made you do it.
While research on ghrelin is still preliminary, in time, scientists may discover this hormone does something besides make us out-of-control eaters. "Ghrelin is an important hormone, but it's just one of many that regulate appetite," says Xavier Pi-Sunyer, M.D., director of the New York Obesity Research Center at St. Luke's Roosevelt Hospital Center and professor of medicine at Columbia University. "It may be a meal initiator since levels rise just before eating and drop immediately after, but more research is needed to understand the role it plays in regulating food intake."
Fortunately, it's easy as pie to outsmart ghrelin and prevent it from triggering a feeding frenzy. From what we know now, it seems that all you have to do to keep ghrelin (and related "hunger hormones") down is to stay moderately full and avoid getting really hungry.
Not surprisingly, then, the best way to regulate your appetite and still lose weight is to eat six healthful, lowfat mini-meals a day (or "graze"), experts say. "Frequent eating is linked to lower body fat, less stress hormones and less insulin response," says Dan Benardot, Ph.D., R.D., associate dean of research for the College of Health and Human Sciences at Georgia State University, Atlanta, who recommends eating every three hours or so to stay satiated and energized.
The many fringe benefits of grazing
In addition, grazing can encourage better eating habits, says sports nutritionist Nancy Clark, M.S., R.D., author of Nancy Clark's Sports Nutrition Guidebook, Second Edition (Human Kinetics, 1997). "Because grazing keeps you full, it makes it easier to avoid the extreme hunger that triggers bingeing on high-fat foods like bacon and high-carb foods like cakes and cookies. With grazing, instead of reaching for the carrot cake, you reach for the carrots. Instead of diving into a slice of apple pie, you choose a fresh, juicy apple," says Clark.
As well as helping you stay full and lose weight, grazing can discourage undereating -- another major (if highly underrated) cause of weight gain, says weight-loss counselor Katherine Tallmadge, M.A., R.D., author of Diet Simple (LifeLine Press, 2002). "If you skip meals -- especially breakfast -- you are more likely to get really hungry and eat the first thing you see," she explains.
By eating healthy, nutrient-dense foods throughout the day, you'll also thwart the urge to overeat while fueling your body for exercise, says Wayne L. Westcott, Ph.D., author of No More Cellulite (Perigee Books, 2003) and senior fitness/research director at the South Shore YMCA in Quincy, Mass.
You can also stop worrying about scheduling meals and workouts so they don't conflict. Graze, and you can literally eat and run. Plus you'll never again have to postpone aerobics class because you are too stuffed to budge.
"With grazing, you can eat just enough so you can work out at any time," Westcott says. "You won't be skipping meals all day, then gorging at night, when you can't do anything but sit down," he adds.
Also, because grazing eliminates constant fat and carb cravings and bingeing, you'll naturally feel more in control of your eating, says Tallmadge. "Because you're allowed to eat every three hours, you won't ever feel cheated or deprived," she says.
Unlike crash diets, which encourage you to skimp, starve and deprive yourself, grazing gives you the opportunity to develop a whole new relationship with food, Tallmadge explains.
Instead of viewing food as the enemy that makes you fat, you begin to appreciate it for what it truly is: the fuel we need to help our bodies stay healthy and strong.
Four rules for grazing right
Building an eating strategy around grazing is easy and fun, and we have lots of tips and recipes to get you started. That said, grazing won't help you lose weight and may even backfire unless you follow these four simple rules.
1. Practice portion control. This is the key to success--not to mention a huge fringe benefit. By learning what a healthy (as opposed to a restaurant-size) portion really looks like, you'll never unwittingly eat for two (or three) when you dine out--or in. According to the American Dietetic Association, most people have no idea what constitutes a healthy serving size. Here's a quick primer to help:
* 1.5-ounce serving of cheese four stacked dice
* 1/2 cup cooked pasta, rice or veggies = a tennis ball cut in half
* 1 cup raw veggies = a tennis ball
* 2-3 ounces cooked lean meat, poultry or fish = a deck of cards
2. Divvy up the calories to stay full all day. If you're following an 1,800-calorie diet, divide the calories into six 200- to 400-calorie mini-meals, says Tallmadge. For example, split up breakfast into a 400-calorie morning meal and a 200-calorie midmorning snack, and then do the same with lunch and dinner. The breakdown doesn't have to be precise--you can split calories up however you want. Just remember that 300 calories are a substantial snack that should keep you satisfied for about three hours. Good examples: a handful of nuts, several pieces of fruit or a low-fat healthy frozen dinner.
3. Plan your meals and shop accordingly. Nothing ruins grazing faster than an empty refrigerator. Without healthful foods on hand for mini-meals and snacks, you'll get so frustrated and hungry, you'll probably head for the nearest fast food or deli or start dialing for pizza.
To avoid this scenario, make sure your refrigerator, kitchen cabinets (desk drawers at work too) are brimming with healthy choices like dried fruit; nuts; yogurt; whole-grain breads, crackers and cereals; fresh fruits and vegetables; and lean protein (chicken, turkey, fish, eggs, lowfat dairy foods and soy products). "Plan ahead!" says Tallmadge. "If you're going to eat three servings of fruit each day, when you're at the farmers market or grocery store on the weekend, buy 21 pieces of fruit for the week. By having nutritious foods available, you'll dodge unhealthy temptations."
4. Never go more than three hours without eating. The point of grazing is to stay full, so don't even think of skipping a mini-meal, no matter how mini it seems. Ghrelin is triggered by hunger and could kick in at the first sign of a rumbling stomach.
By incorporating these four rules, you'll manage your weight, stay full, feel healthy and have all the energy you need to get and stay in great shape.
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