The Easiest Change You Can Make to Your Post-Holiday Diet

You study nutrition labels at the grocery store and pore over menus and cookbooks for the healthiest choices. Yet if you're like most people, you don't give nearly as much thought to what you use to wash down all that wholesome food.

It's time to start. According to one recent report, Americans get an average of 22 percent of their daily calories from beverages. Sound hard to believe? "Since most beverages don't fill us up the way food does, it's easy to consume a lot of calories in liquid form and not even realize it," explains Molly Morgan, a New York-based dietitian. Unless you pay attention, those extra calories can undermine your best intentions for staying healthy.

In terms of nutrition, drinks are a mixed bag. Many harbor unhealthy ingredients such as sweeteners and artificial colors, while others are veritable health elixirs, rich in antioxidants, vitamins, minerals, and compounds that help prevent chronic illness. Most, of course, have both health benefits and drawbacks. By understanding the potential pros and cons of common beverages, you'll know which ones to reach for, which to toss, and which to modify. To that end, our experts helped us put together this cheat sheet.

Smoothies

Calories
150 to upward of 500, based on the contents

Pros
When they contain healthy ingredients, smoothies can deliver big on vitamins, minerals, antioxidant compounds, and calcium. They're a good way to add a serving or two of fruit to your day. Berries, bananas, mango, and melon all make good options.

Cons
Some store-bought smoothies are packed with calories, sugar, and artificial ingredients, says behavioral nutritionist Joy Kettler Gurgevich. Read menus and labels carefully.

Bottom Line
The best smoothie is the one you make yourself. For a basic smoothie, blend 1 to 2 cups of juice and/or milk (or milk alternative) with two cups frozen or fresh fruit (such as bananas, strawberries, and blueberries).

Related: 8 Surprising Ways to Tame Your Sweet Tooth

Herbal Tea

Calories
With nothing added, about 2 calories

Pros
Long used to treat various conditions, certain herbal teas (also known as infusions or tisanes) have medicinal value, says integrative-medicine pioneer Andrew Weil, M.D. Try sipping a cup or two of peppermint tea for indigestion, for example, or chamomile to promote relaxation. Ginger tea may ease nausea, marshmallow root may soothe sore throats and coughs, and nettle blends make for a mineral-rich health tonic.

Cons
The same properties that give herbal teas their healing potential may also cause problems for some people. (Peppermint, for instance, may trigger acid reflux in those prone to it.) And since herbal teas lack catechins, don't expect the same disease protection that true tea offers, says Weil.

Bottom Line
Experiment with herbal teas to promote health or ease minor ailments, but consult an herbalist for more extensive advice.

Tea

Calories
With no added sugar, honey, or milk, 0 calories

Pros
All from the Camellia sinensis plant, black, green, and white teas contain antioxidant compounds called catechins. This may explain studies linking tea consumption to a host of benefits, including stronger immunity and a lower risk of diabetes, cognitive impairment, heart attacks, and some cancers. The less tea is processed, the more catechins it retains. White tea has the most; black tea has the least.

Cons
All true tea still contains caffeine, which makes some people jittery. Although evidence is mixed, adding milk to tea may block the healthful effects of catechins. Pass up bottled iced teas that contain high-fructose corn syrup, artificial colors and flavorings, and other unhealthy ingredients.

Bottom Line
Tea is truly a health beverage; keep drinking it -- or start.

Related: 47 Ways to Maximize Space in Your Kitchen

Cow's Milk

Calories
A cup of whole milk, 146 calories; low-fat, 102; and nonfat, 86

Pros
A nutrient-rich 8-ounce serving of milk delivers about 300 mg of calcium, along with vitamins A and D and about 8 g of protein.

Cons
"A lot of people have trouble digesting lactose [milk sugar]," which can trigger digestive problems, Gurgevich explains. Others are allergic to casein, or milk protein. Conventional milk may be produced with added growth hormones and antibiotics.

Bottom Line
If you drink cow's milk, choose organic, and as a rule stick to low-fat or nonfat varieties. But for women trying to conceive, it may be worth including full-fat dairy; a 2007 study suggests that consuming whole dairy products may reduce the risk of infertility, while drinking low-fat milk may increase it.

Juice

Calories
50 to 160 calories per cup, depending on the juice

Pros
Many juices deliver vitamin C and other antioxidants. Research has linked fruit and vegetable juice consumption to a lower risk of Alzheimer's disease. Specific juices convey particular benefits: Apple appears to have anticancer effects on the colon, Concord grape may protect memory, cranberry may help prevent urinary-tract infections, and pomegranate contains high levels of antioxidants.

Cons
"Many are diluted versions that contain added sugars, flavors, and artificial colors," says Gurgevich. "Plus, if they've been sitting on the shelf, their nutritional benefits may be depleted."

Bottom Line
Squeeze your own to ensure freshness. If that's not feasible, "be a detective in the juice aisle," explains Morgan, as even some so-called healthy brands contain added sugar. Choose antioxidant-rich varieties and drink in moderation. But don't use juice as a replacement for whole fruits and veggies, which offer more fiber and other compounds.

Water

Calories
0 calories

Pros
Water carries nutrients to cells, moistens membranes, and helps flush out toxins and waste. "Replenishing your body's supply of water is crucial for good health," says Gurgevich. Since research has debunked the notion that everyone needs eight glasses of water a day, stay hydrated by drinking when you're thirsty and after exercise.

Cons
Depending on where you live, your tap water may be contaminated with lead, pesticides, and chlorine byproducts. As for bottled water, some brands are packaged tap water, and plastic bottles can leach toxins into the water they contain.

Bottom Line
Make pure, clean water your beverage of choice. "Drink filtered water whenever possible," says Kathie Swift, R.D., nutrition director of the UltraWellness Center in Lenox, Massachusetts. "Store it in stainless steel thermoses rather than plastic containers." If you crave more flavor, squeeze in a lemon or lime rather than buying flavored waters that contain sweeteners or artificial colors.

Milk Alternatives

Calories
A cup of regular soy milk, about 100 calories; almond milk, 60; and rice milk, 120

Pros
"Soy milk and other alternatives make good choices if you don't like or can't tolerate cow's milk," explains Morgan. They don't contain lactose or casein, rendering them easier to digest for some people. Almond milk is rich in vitamin E and magnesium, while soy milk is high in protein and potentially healthful isoflavones.

Cons
Some people find soy milk causes gas and bloating, while others are allergic to soy. Rice milk is super-sweet and very low in protein, making it not the best choice for kids.

Bottom Line
Milk alternatives can be a healthful substitute for dairy; pay attention to how your body reacts to them. Whichever nondairy drink you choose, says Morgan, make sure it is fortified with calcium and vitamin D.

Coffee

Calories
2 calories a cup for black coffee; cream and sugar up the calories

Pros
Once viewed as a guilty pleasure at best, coffee now makes headlines for its potential health-giving properties. Recent research has linked regular consumption to a lower risk of type-2 diabetes, Parkinson's disease, gallstones, and some types of cancer. A study published in Annals of Internal Medicine found that, over the course of 24 years, women who drank two to three cups a day had a moderately lower risk of dying from all causes than their non-coffee-drinking peers.

Cons
Despite coffee's possible benefits, "its caffeine is a drug and can be addictive," says Weil. It can trigger and worsen gastrointestinal problems, insomnia, irregular heartbeat, and anxiety, and may also raise cholesterol. And many coffee drinks are very caloric; a 16-ounce caramel Frappuccino with whipped cream, for instance, has a whopping 380 calories. What's more, many conventional coffee beans are heavily sprayed with pesticides.

Bottom Line
"Take note of how it affects you," suggests Weil, and drink moderate amounts or abstain accordingly. Look for organic varieties.

Decaf

Calories
Same as regular coffee

Pros
The study that found a lower risk of death in regular coffee drinkers showed a small reduction in mortality rates with decaffeinated coffee. Other research suggests that regular consumption of decaf coffee may help lower risk of type-2 diabetes in women.

Cons
Contrary to popular belief, decaf isn't truly caffeine-free: A 2006 study found that most major brands of decaf still contained 8.6 to 13.9 mg of caffeine, about an eighth of what's in an 8-ounce cup of regular coffee. Like caffeinated varieties, decaf coffee can raise LDL ("bad") cholesterol, possibly because of the type of bean used. The decaffeination process itself also poses a problem: Two of the chemical solvents sometimes used to remove caffeine are harmful to health -- and one is a suspected carcinogen.

Bottom Line
If you want to avoid caffeine, don't rely on decaf coffee. If you do drink it, look for brands made with safer decaffeination methods, such as the Swiss water process (often indicated with a logo on packaging).

Wine

Calories
118 per 5-ounce serving

Pros
Moderate amounts of wine have been shown to boost HDL ("good") cholesterol, thin the blood, and potentially lower the risk of both cardiovascular disease and cognitive decline. Red wine may have additional advantages: It's rich in resveratrol, a plant chemical that may help prevent blood clotting and plaque formation in blood vessels. Although human research is sparse, mouse and lab studies suggest that resveratrol may help prevent cancer and increase longevity.

Cons
Wine may increase triglyceride levels and trigger migraines in susceptible people. Plus, research shows that alcohol in general can increase the risk of breast cancer. Excessive use is linked to several other types of cancer along with osteoporosis.

Bottom Line
As with any type of alcohol, moderation is key. That means no more than one drink a day for women and no more than two for men.

Beer

Calories
For regular beer, about 140 calories per 12-ounce serving; light beer, about 100 calories; flavored malt beverages, 190 to 241 calories

Pros
Like other types of alcohol, beer is associated with decreased rates of cardiovascular disease.

Cons
Regular beer is high in calories and carbohydrates, which may help account for the stereotypical "beer belly" that some devotees develop. As with other types of alcohol, excessive use ups your risk of several types of cancer and osteoporosis.

Bottom Line
Like wine, beer is fine in moderation -- but watch its effects on your waistline.

Liquor

Calories
About 98 calories per 1.5-ounce serving for vodka, gin, and other forms of liquor

Pros
Also known as spirits and distilled beverages, liquor has been linked to the same health benefits that beer and wine confer.

Cons
Liquor has a much higher alcohol content -- 40 percent alcohol or more -- than beer (3 to 8 percent alcohol) and wine (11 to 14 percent alcohol). Adding sweet mixers such as juice and soda can make it particularly easy to consume higher amounts of liquor without realizing it, increasing the health risks and calorie count. As with other types of alcohol, excessive use ups your risk of several types of cancer and osteoporosis.

Bottom Line
Limit your intake to small amounts.

Soda

Calories
About 150 calories per 12-ounce can

Pros
Soda counts toward your daily fluid intake. "And that's the only positive thing about it," notes Morgan.

Cons
Dubbed "liquid candy," colas and other soft drinks are loaded with high-fructose corn syrup, calories, and caffeine and contain virtually no nutrients. Studies have tied soft-drink consumption to higher rates of obesity, type-2 diabetes, and cavities. Natural soft drinks lack the additives of their mainstream peers but often contain large amounts of sugar.

Bottom Line
"Skip the sodas," advises Gurgevich.

Diet Soda

Calories
0 to 1 calorie

Pros
Diet soft drinks contribute to daily fluid intake -- but contain no high-fructose corn syrup or sugar.

Cons
Most diet drinks are flavored with artificial sweeteners that come with their own set of health concerns. "Some evidence suggests that aspartame [NutraSweet] may harm the body's nervous system," Gurgevich explains. Other research shows that diet beverages confer the same risks that regular sodas do, even increasing the risk of metabolic syndrome, which is associated with heart disease. And diet sodas may actually make you gain weight. "Artificial sweeteners fool the body into expecting sugar," says Weil. "In the long run, they can increase sugar cravings, leading you to consume more calorie-dense foods."

Bottom Line
Skip the diet sodas, too. Drinking them squeezes healthier beverages, like water, out of your diet.

What About Holiday Drinks?

Hot cocoa, cider, and eggnog are popular -- and tasty -- holiday indulgences. Here's the nutrition lowdown on these seasonal favorites.

Hot Chocolate

Research has shown that high-quality dark chocolate is rich in antioxidant compounds that may slightly reduce blood pressure and help prevent cancer. But the type of cocoa makes a difference. "Stay away from packaged hot cocoa mixes," advises Gurgevich, who points out that most conventional brands contain artificial flavors, thickeners, and high amounts of sugar or artificial sweeteners such as aspartame. Instead, make your own the old-fashioned way: Melt good-quality dark chocolate; stir in warm organic cow's, soy, or almond milk; and season with honey, agave nectar, cinnamon, or even a dusting of chile powder.

Eggnog

This blend of milk, eggs, sugar, and rum is synonymous with Christmas for many people. It's also packed with calcium -- about 150 mg per half-cup serving, says Morgan. But most packaged nogs are high in saturated fat, sugar, and calories and often laden with artificial additives. Your best bet? Whip some up yourself, using low-fat milk or a milk alternative, organic eggs, and less sugar, and limit yourself to about half a cup.

Apple Cider

Again, avoid brands of bottled cider that contain sugar or artificial sweeteners. Instead, says Morgan, opt for those labeled 100 percent real juice -- they're rich in vitamin C. Mull your own by heating it in a slow cooker or saucepan with cinnamon and cloves.

More from Martha Stewart:
13 Crazy Beauty Tricks That Really Work
19 Tips for Perfect Laundry Every Time
65 Quick and Easy Holiday Decorating Ideas from Martha Stewart
22 Gift-Wrapping Ideas for Turning Any Gift Into Something Spectacular

See more tips for a long and healthy life from someone who's walking the walk.