Hit the weight roomPumping iron keeps your metabolism humming and your silhouette slim. But a recent report from the Centers for Disease Control and Prevention found that a mere 19 percent of women weight-train twice a week or more. It's time to rethink that: "Starting at around age 35, women lose 5 to 10 percent of their lean muscle mass per decade," says Michele S. Olson,
PhD, a FITNESS advisory board member and professor of exercise science at Auburn University at Montgomery in Alabama. "So when you're 45, even if you weigh the same as you used to, you've probably lost about eight pounds of muscle and replaced it with eight pounds of fat." And that switcheroo leads to a 48-calorie-a-day decrease in your RMR. It may not sound like much, but it adds up to about five pounds of fat gained a year.
Make it happen: In addition to regular cardio sessions (intervals are especially good for torching calories and boosting your post-exercise burn), strength-train. "Studies have found that women who do eight to 12 reps of three upper-body and three lower-body strength exercises four times a week using moderately heavy weights can gain about a pound of muscle each month," Olson says.
Ditch crash dieting.
More than half of people who are trying to lose weight say that they crash diet or fast, follow a restrictive program, or skip meals, according to a recent survey. You've probably heard that when you don't eat enough, your body goes into starvation mode and your metabolic rate decreases. Although some researchers have questioned the validity of this claim, a recent study published in Obesity backs it up. People who reduced their calorie intake by 25 percent or consumed just 890 calories a day experienced a drop in their RMR. And that's not all: "If you're not eating enough, you're most likely losing muscle, not fat," says Rachel Berman, RD, the author of Boosting Your Metabolism for Dummies. That's particularly true if you're skimping on protein or essential fats. "Your body will break down its own muscle tissue to get the amino acids it needs," says Caroline Cederquist, MD, the medical director of Cederquist Comprehensive Medical Weight Control in Naples, Florida.
Make it happen: Eat up! If you exercise regularly, you need at least 1,500 calories a day. Active women may require 0.5 to 0.75 grams of protein per pound of body weight, according to Nancy Clark, RD, the author of Nancy Clark's Sports Nutrition Guidebook. That's 70 to 105 grams a day for a 140-pound woman. You can reach that range, for example, by eating one egg (six grams), six ounces of Greek yogurt (17 grams), two tablespoons of almond butter (seven grams), a four-ounce salmon fillet (31 grams), and a cup of pinto beans (15 grams).
Don't party too hard.
A glass of wine a day probably won't cause weight gain. Research shows that people who drink small amounts frequently have healthier body mass indexes than those who drink larger amounts less frequently. Several studies have found a link between occasional bouts of heavy drinking -- consuming at least six cocktails at a time -- and excessive abdominal fat. "The liver normally breaks down stored fat for energy," Dr. Cederquist says. "But with heavy alcohol intake, your body prioritizes the detoxification of the alcohol over the metabolism of fat." Translation: You hold onto fat and torch fewer calories. Buzzkill!
Make it happen: Sip no more than one drink a day. And make it a glass of wine, preferably red. In a recent review of studies at the University of Navarra in Spain, vino wasn't associated with weight gain, but hard liquor was. This may be because the compound resveratrol, found in the skin of grapes, inhibits the production or accumulation of fat.
Cut back on sugar.
The average American consumes almost 152 pounds of sugar a year -- or 43 teaspoons a day! It's not just sweets but simple carbohydrates of all sorts -- chips, pretzels, white bread, and pasta -- that murder your metabolism. "Simple carbs and sugar stimulate the release of insulin," Dr. Cederquist explains. "As people age or gain weight, especially in the abdomen, the body loses sensitivity to insulin, and glucose is unable to enter the cells." That means your body stops using simple carbs for energy and instead stores them as fat, so you wind up hungrier...and heavier.
Make it happen: The American Heart Association suggests that women limit added sugars to no more than about 100 calories (the equivalent of six teaspoons of sugar) a day, but that's easier said than done. "Food labels don't make a distinction between added and natural sugar; they're lumped into one category," Berman says. Limit your consumption of added sugar by keeping processed foods in check and scanning ingredients lists for any word ending in ose (including dextrose, sucrose, maltose, and lactose), as well as honey, molasses, high-fructose corn syrup, and fruit juice concentrates. The closer to the top of the list these ingredients are, the higher the sugar content.
Get more zzz's.
According to recent data from the National Center for Health Statistics, nearly 30 percent of adults report getting six or fewer hours of shut-eye a night. That's a serious nightmare when trying to shed pounds: A 2010 University of Chicago study found that test subjects who snoozed only five and a half hours a night were hungrier and lost 55 percent less weight than those who slept eight and a half hours a night. "Sleep deprivation interferes with your body's ability to metabolize foods," notes Pamela Wartian Smith, MD, the author of Why You Can't Lose Weight. "It also makes you produce more of the hunger hormone ghrelin and less of the appetite suppressor leptin."
Make it happen: Go to bed already. Although eight hours a night is ideal, seven is enough to ward off weight gain and enhance overall health, Dr. Smith says. Even if you're not getting that amount, strive to turn in and wake up at the same time every day. "This reinforces a consistent sleep rhythm and reminds the brain when to release sleep and wake hormones," says Frank Lipman, MD, the author of Revive: Stop Feeling Spent and Start Living Again. And cut back on caffeine; it blocks sleep neurotransmitters, even in small doses or when consumed in the a.m.
How to Bounce Back After a Bad Night's Sleep
Angst affects not only your mental health but also your metabolism. A recent study from Rutgers University in New Jersey found that chronic stress leads women to reach for high-sugar, high-fat comfort foods, and those who were the most frazzled had more abdominal fat. "Chronic stress causes cortisol secretion," Dr. Cederquist says. "Cortisol prompts fat in the body to be relocated and deposited deep in the abdomen, and this visceral fat is the key to the metabolic slowing that occurs with age, weight gain, or hormonal changes."
Make it happen: Take a good, hard look at the stressors in your life. Strive to minimize them wherever possible, whether that means taking a personal day (or full-on vacay) from work or coming up with a new system for organizing your desk. Better yet, practice stress-management techniques, like regular exercise and meditation. "Just five minutes of mindful breathing in the morning is a great place to start," Dr. Lipman says. Go to meditationoasis.com, a site with dozens of free meditation podcasts to help you chill out. The more relaxed you are, the better everything in your life will function, including your metabolism.