If you’re like many women over 40, you’ve probably noticed that it’s become a lot easier to gain a few pounds than to lose them. The foods that you ate without care in your 20s and 30s now stick to your body like glue, adding bulk to your midsection. The good news: The solution to a slim, firm body at 40-plus is no farther than your fridge. Research shows that, when combined with a little regular exercise, what you eat and when you eat it are your metabolic secret weapons for building muscle mass, the body’s prime calorie-burning tissue and a key driver of your metabolism.
“The main culprit that slows metabolism and often leads to yo-yo dieting is what I call shrinking muscle syndrome,” says Caroline Apovian, MD, director of the Nutrition and Weight Management Center at Boston Medical Center and the author of The Overnight Diet: The Proven Plan for Fast and Permanent Weight Loss. Starting at age 30, most people begin to lose about half a pound of the metabolism-revving tissue each year. Poof! Gone, just like that. And at age 50, the rate doubles. “The average sedentary woman may have lost nearly 15 pounds of muscle by the time she reaches her late 50s, a change that could cause her to gain nearly the same amount in body fat,” says Wayne Westcott, PhD, a Prevention advisory board member and the director of fitness research at Quincy College in Massachusetts.
But too-tight jeans, a puffy midsection, and an increased risk of diabetes don’t have to be your future. (Your chances of winding up with all of the above increase with each pound of muscle you lose.) Here’s how to safeguard muscle mass and turn up the heat on your body’s natural calorie-frying furnace.
Here’s how to get started:
• Eat healthy, protein-rich foods to support calorie-burning muscle mass, and follow a moderate-calorie diet.
• Strength-train twice a week to fight muscle loss.
• Squeeze in quickie cardio workouts 3 times a week to hike all-day calorie burn.
Metabolism Booster #1
Keep tabs on protein.
You already know to keep calories and fat in check, but you’ll fan the flames of your metabolism by putting another nutrient on your radar: protein, the building block of lean muscle mass. Each time you eat a protein-rich food—say, a piece of fish or cheese—your body goes to work, breaking it down into smaller particles called amino acids. “The amino acids enter your bloodstream and are then absorbed by your muscle tissues and other cells,” says Douglas Paddon-Jones, PhD, director of exercise studies at the University of Texas Medical Branch. “Once the amino acids end up in your muscles, your body starts putting them back together—sort of like Legos—into your muscle tissue.” This is called muscle-protein synthesis, and it’s the process your body uses to build and maintain muscle mass.
However, just like those rehab-loving design gurus on HGTV, your body breaks down muscle as regularly as it builds it. “All of the cells in your body need protein to function. When there aren’t enough amino acids from food available in the bloodstream, the body will start to break down and harvest amino acids from your muscle in order to keep more vital cells—like the ones in your brain and other organs—functioning,” says Dr. Paddon-Jones. “This is a natural, continuing cycle. Muscle-protein synthesis goes up after you eat a meal with protein, and your body switches back to muscle-breakdown mode a few hours after you’ve eaten. Normally, the ups and downs equal out and your muscle mass stays the same.” However, eat too little protein for too long and your muscles start to shrink, eventually causing your metabolism to take a nosedive.
And new research suggests that many of us may need more protein than we realize. The current RDA is 0.8 g of protein per kilogram of body weight, but several studies have found that 1 to 1.2 g may be more protective against age-related muscle loss. Dr. Apovian uses a slightly higher amount—1.5 g/kg of ideal body weight—to successfully help herself, as well as her patients, shed body fat and maintain lean muscle mass. According to her, if you’re 5-foot-5 and 130 pounds, you should aim for about 90 g of protein. While that may sound like a lot of protein, it’s doable when you break it down. Four ounces of chicken or beef provides nearly 30 g in one shot, and a single serving of Greek-style yogurt packs nearly 20.
While most Americans consume plenty of protein, research shows that some women begin skimping on the muscle-sustaining nutrient as they age, consuming less than the RDA. Calorie-conscious dieters also tend to cut back on protein, when they should be doing the opposite. “Cutting back causes your body to rob your muscles for energy, leaving you thinner but also flabbier and weaker,” says Dr. Apovian. “Not only does losing muscle make your clothing fit poorly, but you begin to burn fewer calories, so even if you’re eating the same amount, you can easily regain the weight you shed.” Having less muscle mass also makes you weaker, making it harder to do simple activities, so you become more inclined to crash on the couch. Eventually, the scale climbs back up and you start all over again, chipping away at muscle mass and putting the chill on your metabolism with each diet you try.
“However, keep in mind that calories still count, especially if you’re looking to drop a few pounds,” says Christine Gerbstadt, MD, RD, the author of Doctor’s Detox Diet: The Ultimate Weight Loss Prescription. “If you’re increasing protein intake, you need to cut back elsewhere.”
Case in point: In a 10-week preliminary study led by Dr. Apovian and Dr. Westcott, baby boomers who exercised regularly and followed a moderate-calorie diet (1,200 to 1,500 calories for women; 1,500 to 1,800 for men), while simultaneously increasing their protein intake to 1.5 g/kg of ideal body weight, lost nearly 5 times more weight than participants who exercised without changing their diets. They also lost 4 more pounds than exercisers who increased protein intake but didn’t keep calories in check. Even better: The calorie- and protein-conscious group gained more muscle, reduced their blood pressure, and dropped 2 inches from their waists.
Metabolism Booster #2
Aim for 20 to 30 g of protein at each meal.
That 16-ounce rib eye at your favorite restaurant may tout well over 100 g of protein, but you’ll have the greatest chance of offsetting muscle loss if you spread out your total daily protein intake evenly, aiming for 20 to 30 g at each meal and snack. “Remember, over the course of a day, there’s a natural balance between muscle breakdown and muscle building,” says Dr. Paddon-Jones. “By eating protein at regular intervals throughout the day, you’ll avoid dipping into breakdown mode for too long at one time.”
Eating protein at breakfast is especially important. “The longest period of muscle breakdown occurs at night, when you’re sleeping and not eating for hours at a time,” explains Dr. Paddon-Jones. “If you skip breakfast or start your day with a protein-light meal—like a bagel, toast, or cereal—you’re missing out on flipping that muscle-building switch back on.”
Spreading out your protein becomes even more important as you rack up birthdays. “How your body reacts to protein, especially with smaller amounts, changes as you get older,” says Dr. Paddon-Jones, noting that whereas a teenager’s body will jump into full muscle-building mode even with smaller amounts of protein, your body needs more—about 30 g—to maximize muscle-protein synthesis. Another bonus: Protein staves off hunger, so you’ll be less likely to snack too.
Metabolism Booster #3
Vary your protein sources
While meat packs a lot of protein in one shot, getting your protein only from animal sources could actually speed muscle loss, according to a 2012 review by the International Osteoporosis Foundation Nutrition Working Group. Why? Meats, as well as grains like wheat and corn, are acid-producing foods that stunt muscle-protein synthesis. The good news: Fruits and vegetables are alkalizing and can help offset some of the muscle-robbing effects of meaty, starchy meals. “Plus, there are a lot of delicious vegetarian sources of protein,” says Dr. Gerbstadt. “Try experimenting with tofu, lentils, or beans. They taste great and tend to be lower in calories.” When you opt for animal protein, avoid high-fat sources such as regular ground beef, bacon, whole milk, or full-fat cheese.
Metabolism Booster #4
Challenge your muscles.
“If you eat enough protein and stay active, you can maintain muscle mass,” says Dr. Apovian. “But to really build new muscle—the key to increasing your metabolism—you’ll need to strength-train too.”
“When you do resistance training, it causes a degree of microtrauma, or tiny tears, to the muscle tissue,” says Dr. Westcott. “Over the next 48 to 72 hours, your body remodels and heals that tissue with amino acids, making it stronger—or, if you’re just starting out and need to gain muscle mass, the muscle slowly grows.” This throws coals onto your metabolism’s calorie-burning fire in two ways: First, the more muscle you build, the more calories you’ll burn each day. Second, the rebuilding process itself requires extra energy, boosting your daily calorie burn by 5 to 9%.
The great news: You don’t have to spend hours in the weight room. “Research shows that you’ll have the same muscle gains with 2 days of strength training as you’d have with 3,” says Dr. Westcott. In a recent study, participants who performed a strength-training program twice a week for 10 weeks had the same increase in muscle mass—an average of 3.1 pounds—as those who added an extra weekly session.
How much protein do you need?
Caroline Apovian, MD, recommends using this formula to determine the minimum amount of protein you should eat daily to offset muscle loss—and protect your metabolism—while you lose weight.
Estimate your ideal weight. “If you’re a woman, start with 100 pounds for the first 5 feet in height, and add 5 pounds for every extra inch,” says Dr. Apovian. “For men, it’s 106 pounds for 5 feet in height, plus 6 pounds for every additional inch. However, if your ideal weight is less than 120 pounds, don’t eat less than 82 g of protein daily.”
Ideal Weight (in lb) ÷ 2.2 = Ideal Weight (in kg)
Ideal Weight (in kg) × 1.5 = Daily Protein Goal (in g)
Sip this to spike up calorie burn
While maintaining and building lean muscle mass is the best way to keep your metabolism humming, research shows that staying hydrated may also increase calorie burn, especially if your beverage is cold and frosty. How? Your body has to heat up icy drinks to reach body temperature, which requires energy. Making your drink of choice green or oolong tea can also give your metabolism an added boost, according to Japanese researchers.
Want to painlessly burn off a few extra calories? Try our refreshing Metabolism-Boosting Iced Lemon-and-Ginger Green Tea:
Combine 10 green or oolong tea bags, 2″ piece peeled fresh ginger cut into thin slices, 3 large mint sprigs, and 1 sliced small lemon in heatproof 2 qt pitcher.
Bring 4 cups water to a boil in saucepan and pour into pitcher.
Stir once and let tea bags steep 6 minutes.
Remove and discard tea bags and mint sprigs.
Add a touch of honey to tea, if desired.
Let cool 20 minutes.
Add enough ice and cold water to make 6 cups.
Serve over ice in glasses with fresh mint sprigs and lemon slices.
Refuel with protein to lose more fat
Men and women who consumed a postexercise protein drink gained more metabolism-revving muscle mass and lost 50% more body fat than those who didn’t refuel after working out, found a study published in Fitness Management. “For about 30 minutes after exercise, muscles are especially receptive to amino acids,” says Wayne Westcott, PhD, the lead study author. “The combo we used—about 24 g of protein and 36 g of carbs—helps speed muscle repair and growth. As long as you eat close to 20 g of protein and 30 g of carbs, you’ll get similar results.” Enjoy this snack—or something similar—soon after exercise.
Top 6 oz organic plain 0% Greek-style yogurt with 1/4 cup Nature’s Path organic granola, 1/4 cup blueberries, and 1/2 cup sliced strawberries.
TOTAL: 238 cal 20 g pro, 31 g carb
Maximize metabolism in minutes
Interval training—alternating between high-intensity bursts of movement and a moderate pace—has been shown to amp up metabolism for up to 24 hours postworkout. “You don’t have to do a lot to see the benefits,” says Wayne Westcott, PhD. “Aim for 15 to 25 minutes of interval training 3 or 4 days per week.” If you’re just getting started or have a lot of weight to lose, do walking or stationary cycling intervals, which are easier on the joints. If you want to challenge yourself, lace up your sneaks and jump rope or go for a run.