One of the simplest ways to cut calories is to substitute noncaloric drinks for sweetened beverages such as soda, fruit drinks and energy or sports drinks. Such beverages are an ideal target, since they supply more than 10 percent of the calories in the average American’s diet, a figure that has risen over recent decades.
Surprisingly, though, there’s no solid evidence that this step by itself really helps people lose weight. Observational studies focusing on the link between noncaloric beverages and weight have produced unclear results because so many other factors come into play. For instance, people who consume diet drinks are likely to be overweight to begin with and may take other weight-control steps as well. What’s more, people who drink such beverages may compensate for the “saved” calories by getting more from other foods.
Recently, the first large randomized study specifically testing such beverage substitution appeared in the American Journal of Clinical Nutrition. Done at the University of North Carolina at Chapel Hill, it involved 318 overweight or obese adults, mostly women. One-third were told to substitute diet beverages for at least two servings of caloric beverages (totaling at least 200 calories) a day, with no other suggested calorie reductions, while another third substituted water. The last third got general weight-loss advice but were not told to switch beverages.
After six months, the diet drink and water groups lost five pounds, on average, compared to about three pounds in the general-advice group. More significantly, they were twice as likely to have lost at least five percent of their body weight.
If you’re very overweight, these are modest results, but still encouraging, according to the researchers, especially since most people tend to gain weight over time. Take additional small but sustainable calorie-cutting steps and the losses would add up.