Sugary soft drinks are a major source of empty calories. Every experienced dieter knows that 32-ounce drink, if it’s got regular sugar, is a major no-no. But diet soda? Many dieters drink it every day without a second thought. Recent results from a long-term study in San Antonio, reported in the Obesity Journal, suggest that we should all give a second thought to our use of artificially sweetened beverages.
Artificial Sweeteners: Not a Sweet Deal
The study, led by Dr. Sharon Fowler of the University of Texas Health Science Center, followed adults in San Antonio, Texas, tracking their weight and use of artificially sweetened beverages over almost a decade. The study was conducted among adults aged 25-64, including over 3000 Mexican Americans and nearly 2000 non-Hispanic whites. In addition to diet soda, these participants were asked about their use of artificial sweeteners in coffee and tea; a cup of coffee with saccharin or a glass of tea with aspartame was counted as an artificially sweetened beverage, too.
The researchers found a clear association between use of diet drinks and increases in obesity and body mass index (BMI). Compared to individuals who did not drink diet beverages, those who did had a 47% greater increase in BMI over a period of seven to eight years. And the individuals who drank the most artificially sweetened beverages (more than 21 per week) had an almost doubled risk of becoming overweight or obese during the course of the study.
How Can Calorie-Free Make Us Fat?
This study hasn’t answered that question definitively, but the researchers do offer several possible explanations. Consuming artificial sweeteners might lead to weight gain through several indirect means. One possibility is that when we decrease the amount of sugar we eat, we may increase fat intake to compensate. Another possibility is that dieters overestimate how many calories they’re saving by using artificial sweeteners and so they feel more comfortable splurging on calories elsewhere in their diets. A third indirect effect may be caused by the fact that artificial sweeteners are actually sweeter than sugar. By getting used to the super-sweet taste of artificial sweeteners, we might distort our taste and increase our appetite for very sweet foods.
There’s even a possibility that artificial sweeteners might have a direct effect on weight gain. Some earlier studies have shown that artificial sweeteners can affect insulin or glucose levels. Other research has shown that a major component of aspartame can prevent the production of leptin, a hormone that helps our bodies sense when we’ve had enough to eat.
What Dieters Can Do Now
So, although the exact mechanism isn’t clear, what is clear is that drinking artificially sweetened beverages is by no means a sure-fire way to help yourself lose weight, and it may even be counter-productive. While the scientists continue to study the why and the how, for dieters, the best bet is to switch to beverages that are naturally low in sugar—unsweetened tea and coffee, freshly squeezed vegetable juices, and good old water.