If you turn to diet drinks to lose weight you may want to reconsider your options
Researchers from Johns Hopkins Bloomberg School of Public Health and Columbia Mailman School of Public Health examined national patterns in adult diet beverage consumption and caloric intake by body weight status
For the study Dr. Sara Bleich, PhD, Associate Professor of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health and lead researcher of this study along with colleagues examined data from the National Health and Nutrition Examination Survey 1999–2010 that asked about dietary habits over the previous 24 hours of 23,965 adults aged 20 and over. The team examined national patterns in diet-beverage habits, sugary-drink consumption and caloric intake by body-weight category.
The results showed twice as many obese people drank diet beverages compared to healthy weight adults. Overall, 11% of normal-weight, 19% of overweight and 22% of obese adults drink diet beverages.
Total caloric intake was higher among adults consuming sugar-sweetened beverages (2351 kcal/day) compared with diet beverages (2203 kcal/day) However, the difference was only significant for healthy-weight adults (2302 kcal/day vs 2095 kcal/day).
Overweight people who consumed diet beverages consumed 88 more solid calories compared to those who consumed sugar-sweetened beverages. Obese participants who drank diet drinks consumed 200 more solid calories a day compared to those who consumed sugar=sweetened beverages.
However, healthy weight adults who consumed diet drinks had 73 fewer solid calories and those who drank sugar –sweetened beverages gained 46 solid calories.
In their conclusion the researchers write “Overweight and obese adults drink more diet beverages than healthy-weight adults and consume significantly more solid-food calories and a comparable total calories than overweight and obese adults who drink SSBs. Heavier US adults who drink diet beverages will need to reduce solid-food calorie consumption to lose weight.”
"Diet-soda drinkers who are overweight or obese are eating more solid food during the day than overweight and obese people who drink sugary beverages," said Dr. Bleich.
Earlier research might help explain the findings, Dr. Bleich said. It's thought that the artificial sweeteners used in the diet drinks may disrupt the brain's sweet sensors, she said.
"If you consume artificial sweeteners, it makes the brain think you are less satiated or full, and as a result you eat more," she said.
The American Beverage Association, the trade group representing soda manufacturers does not agree with the findings.
"Diet beverages have been shown to be an effective tool as part of an overall weight-management plan," the association said in a statement Thursday. "Numerous studies have repeatedly demonstrated the benefits of diet beverages—as well as low-calorie sweeteners, which are in thousands of foods and beverages—in helping to reduce calorie intake."
Losing or maintaining weight, the association said, involves balancing the total calories consumed with those burned through physical activity. This study, the ABA said, looked only at one 24-hour period and didn't ask about physical-activity levels.
According to Dr. Susan Swithers, PhD, Professor of Behavioral Neuroscience at Purdue University and not part of this study related animal research has found that artificial sweeteners disrupt basic learning processes. Sometimes sweet tastes predict caloric intake, as when sugar is eaten. With diet drinks, however, no calories arrive with the sweet taste.
She continues studies in people have found that the brains of diet-soda drinkers respond differently to sugar than the brains of those who don't drink diet beverages. "It's as if the experience with diet soda has made the meaning of sweet tastes confusing or unpredictable," she said.
The experts do agree on one point; these findings are not a reason to go back to regular soda or to consume more.
"Instead, the goal should be to reduce consumption of sweeteners altogether," Swithers said.
Dr. Lichtenstein agreed. "The best option is always water," she said.
This study does not prove that consuming low calorie beverages results in consuming more food. Among the limitations of this study is that consumption was self-reported according to Alice Lichtenstein, DSc, Tufts University, Boston.
This study appears in the American Journal of Public Health.