Celeb Trainer Harley Pasternak: The Easiest Way to Keep Overeating in Check

"Hydration does have many key effects that can aid in your weight loss," Pasternak says

Harley Pasternak is a celebrity trainer and nutrition expert who has worked with stars from Halle Berry and Lady Gaga to Robert Pattinson and Robert Downey Jr. He’s also aNew York Times best-selling author, with titles including The Body Reset Diet and The 5-Factor Diet. His new book 5 Pounds is out now. Tweet him @harleypasternak.

While there is no definitive evidence that drinking water alone helps you lose weight, hydration does have many key effects that can aid in your weight loss. I myself carry a bottle with me everywhere I go; it’s practically fused to my hand. I’m currently obsessed with smartwater sparkling, because it just feels refreshing, so I drink more.

So how can something as simple as drinking water affect our waistlines?

1. Water can help you from overeating.

Chugging a bottle or a tall glass of water before you eat or drinking during your meal fills up your stomach so that you don’t have to eat as much to be full.

According to a 2008 study published in the Journal of the American Dietetic Association, drinking water before a meal leads to eating about 13 percent fewer calories at that meal. That’s nothing to sneeze at! Thirteen percent off of a 2,000-calorie diet is 260 calories. And while it’s not an exact science, if you factor in that there are approximately 3,500 calories in one pound, that’s a 27-lb. loss over a year!

There is a rumor out there that drinking water with meals disrupts digestion, which is just plain wrong. I blame this on one or two “natural” food and lifestyle bloggers out there (that are actually infamous for their nonsense advice) that claim that drinking liquids during your meal dilutes your digestive juices. Not surprisingly, this is mere nonsense. Drinking water with your meals actually aids in your digestion, as long as you’re not using it to wash down poorly chewed food (I’m looking at you, competitive hot dog eaters!).

2. Thirst can be confused for hunger.

When you’re at work and out running errands and hunger pangs hit, try drinking water before snacking. Our bodies often exhibit hunger symptoms when we’re just thirsty. It’s better to drink some water and see if your hunger goes away than to snack if you don’t need it! If you do eat a snack, take some fluids in, too; it will fill you up faster.

3. Water can help you stay more energized and active.

Symptoms of even mild dehydration include fatigue, headaches, reduced concentration and reduced cognitive function. While none of these are pleasant, perhaps the most important here to weight loss is fatigue. A fatigued body expends less energy (meaning fewer calories burned) and a fatigued mind leads to poor meal choices.

A 2012 study published in the Journal of Nutrition found that even mild dehydration, or about 1.5 percent loss in normal water volume, can cause these negative effects. Since experts agree that thirst tends to appear between 1- and 2-percent dehydration, we could be experiencing dehydration before we even feel thirsty! Hence my constant smartwater-in-hand.

The study also found that women tended to be more adversely affected by dehydration than men, so it’s especially important for women to stay hydrated.

4. Drinking water may increase metabolism.

While there is no definite evidence, there is some research out there that suggests that drinking water may give our metabolisms a boost. A 2003 study published in The Journal of Clinical Endocrinology & Metabolism found that drinking 500 mL of water (or 16.9 oz., roughly the size of a standard bottle of water) boosted subjects’ metabolic rate by 30 percent, peaking at 30 to 40 minutes after ingestion.

5. Drinking water keeps your hands and mouth occupied.

One of the main culprits of unnecessary snacking is boredom or a need for oral fixation. Drinking water keeps both your hands and your mouth busy so you don’t mindlessly eat. If you like the taste of what you’re drinking, you can drink more, which is why you can also try a spritz of lemon or a couple sprigs of mint or a calorie-free naturally sweetened drink (like vitaminwater zero and POWERADE ZERO). As I said earlier, I like sparkling water during the day because the bubbles prevent taste bud boredom.

So how much water is enough? There are differing opinions among experts, but I do find that the “8×8 Rule” (eight 8-oz. glasses a day) is a little too generalized. I mean, should that be the same recommendation for a 120-lb., 5-ft., 5-in., female who is relatively sedentary and a 6-ft., 4-in., 200-lb. man who is very active? A common recommendation is to go by urine color — your urine should be a pale yellow. But since some medications can affect urine color, another way is to take your body weight and divide it by half. That’s the minimum amount (in ounces) you should be drinking. So if you’re 150 lbs., you should be drinking a minimum of 75 oz. a day, and more if you’re more active.

With all this in mind, there’s not much you can do for weight loss that’s easier than just drinking more water, so give it a try and let me know how you feel by tweeting me @harleypasternak.

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