You need to pay more attention to your fluid intake in the summertime. In warm weather, you sweat more, and if you’re also more active, you’ll sweat still more. So it’s important that you hydrate. But not all fluids are equal. Some beverages are loaded with sugar — and calories. We don’t sense the calories in liquids the same way we do as in solid foods, so we don’t realize how many “hidden” calories we’re consuming when we’re drinking some beverages. This is true for alcohol as well as for non-alcoholic drinks. Madelyn Fernstrom, a “Today” contributor and director of the Weight Management Center at the University of Pittsburgh Medical Center, was invited on the show to tell us which drinks to avoid — and which ones to choose:

Forget the old adage: drink at least eight (eight-ounces) glasses of water a day to stay hydrated. Sixty-four ounces is an arbitrary amount. Recent studies show that drinking for thirst is fine and meets the body’s needs. It used to be thought that when you were thirsty, it was “too late” — and that you were already dehydrated. Not true! So drink when you are thirsty.

Best Choice:

Water
Although there are many choices for bottled water, many people get tired of drinking water. Also, many people think that when they exercise they need a sports drink to “replenish” lost nutrients and fluids. That’s not so. Water will hydrate you, and it doesn’t have the calories found in Gatorade or other sports drinks.

Tap
Use a filter if you’re not satisfied with the water directly from the faucet.

Bottled
Waters containing minerals give them different flavors. Brands include Dasani, Aquafina, Fiji, Evian, Voss, Poland Spring, Deer Park, and Smart Water. Brands of sparkling water include San Pelligrino and Perrier.

What to avoid:
Fruit punches

What to choose:
Low-calorie flavored drinks: Crystal Light drinks or low-caloried iced tea (Diet Snapple and Lipton’s Diet Green Tea).
Note: Low-calorie sweeteners are usually a mixture of Splenda (sucralose), acesulfame K, or Nutrasweet (aspartame). All taste a little differently, depending on the sweetener blend, but all are safe.

Low-calorie fruit drinks: Diet V8 Splash, light orange juice (50 percent less calories than regular orange juice (Tropicana and Minute Maid), and light cranberry blend juices (Ocean Spray).

Low-salt tomato juice or V8 juice

What to avoid:
Regular soda

What to choose:
Any diet soda with or without caffeine. (You want to limit your caffeine intake, as it can be dehydrating in high amounts.) Limit yourself to four cans of caffeinated soda such as cola, Dr. Pepper and Mountain Dew. Choose caffeine-free soda after that. Sodas without caffeine include orange, root beer, and Seven-Up.

Club soda or flavored sparkling water 

What to avoid:
Regular sports drinks such as Gatorade and Powerade

What to choose:
Propel, low-calorie Powerade, or Glaceau fruit-flavored vitamin water.

What to avoid:
Frappuchinos and other frozen drinks made with sugar, sugar syrups and whole milk (even soy milk).

What to choose:
Frozen latte made with skim milk and either a low-calorie sweetener or low-calorie syrup.

Don't like low-cal sweeteners? Here are some options:

• Water down your juice: Mix one part regular 100 percent juice with two to three parts water.
• Add a splash of 100 percent juice to a tall glass of seltzer or club soda.
• Put a wedge of lemon, lime, or orange in a glass of sparkling water or still water.
• Add club soda to regular soda.

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