Soft Drinks and Obesity: Scientists Study the Link

“Eat your calories. Don’t drink them,” dietitians at the Pritikin Longevity Center® have for years advised guests wanting to shed weight. That’s because calories in food form, say, apples, are much more satisfying than the same number of calories in liquid form (apple juice). A satisfied appetite can keep hunger from sending you places you don’t want to go, explains Gayl Canfield, PhD, RD, Director of Nutrition at Pritikin.

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“Eat your calories. Don’t drink them,” dietitians at the Pritikin Longevity Center® have for years advised guests wanting to shed weight.
That’s because calories in food form, say, apples, are much more satisfying than the same number of calories in liquid form (apple juice). A satisfied appetite can keep hunger from sending you places you don’t want to go, explains Kimberly Gomer, Director of Nutrition at Pritikin.

Never has this advice been more important for Americans, with our ever-burgeoning waistlines and epidemic rates of obesity, especially among U.S. kids and teenagers, where scientists are discovering a tragic connection between daily consumption of soft drinks and obesity.

But there’s also good news.  Getting rid of soft drinks gets rids of pounds, and quickly.

In a study that monitored the drinking habits of 548 sixth and seventh graders for two years, David Ludwig, MD, at Children’s Hospital Boston found that for each additional daily serving of a soft drink, the incidence of obesity was significantly increased.*

Teenagers Lose Weight

In other research, teenagers who cut back on sugar-rich drinks reduced body fat – up to a pound a month.** That’s the only behavior they changed in the study. They didn’t stop eating cheeseburgers and fries. They didn’t even exercise more. Simply reducing consumption of sugary drinks yielded a modest reduction in weight.

In the study, Dr. Cara Ebbeling of Children’s Hospital Boston and fellow scientists randomly assigned 103 adolescents aged 13 to 18 years who regularly consumed sugar-sweetened drinks to one of two groups. The teenagers in the first group, the control group, kept drinking their usual amount of calorie-rich sodas, juices, punches, lemonades, and sports drinks – totaling about 2.5 servings daily, or 375 calories worth.

The kids in the experimental group got to choose whatever noncaloric drinks they wanted – water, diet sodas, or no-calorie juice drinks.  Every week, supermarkets delivered their no-calorie choices to their homes. Periodic phone calls from the scientists’ staff and refrigerator magnets (“Think Before You Drink”) provided reminders.

To burn off the 250 calories in a 20-ounce bottle of regular soda pop, a 135-pound person would have to:

1. walk three miles in 45 minutes
2. play vigorous basketball for 40 minutes
3. bike vigorously for 22 minutes

After six months, the kids in the control group gained weight. Dr. Ebbeling and her team calculated that a single 12-oz sugar-sweetened beverage per day translated to about one pound of weight gain over four weeks. “Sugary beverages have no nutritional value and seem to make a huge contribution to weight gain,” they wrote.

Heaviest Teens Benefit Most

The kids in the experimental group lost weight. They had cut their consumption of sweetened drinks by 82%. The heaviest teens benefited the most, losing about a pound a month.

Sure, this is not dramatic weight loss, but keep in mind:  All they did was exchange calorie-rich drinks for no-calorie drinks, and they lost weight.  And how wonderful, after six months, to lose weight rather than gain weight, like the kids who kept drinking sugar-sweet beverages did.

Wonderful, too, noted the authors, was how easily the children in the experimental group adapted to their new no-calorie drinks. “A simple environmental intervention almost completely eliminated sugar-sweetened beverage consumption,” they concluded.

* Lancet, 2001; 357: 505.

** Pediatrics, 2006; 117: 673.



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