Before the rising debate about soft drinks and obesity gets so polarized that no one is listening to anyone, let's get straight some of the current research, trends and implications. If we don't, we will head off in a wrong direction, pillory a wrong culprit and, worse, delay real remedies.
Make no mistake: The soft drink industry is big business, and soda consumption has increased significantly over the past 20 years. In the same 20 years, the number of obese American adults also has increased significantly. Cause and effect? Some want us to think so, but the evidence is just not there that sweetened soft drinks are a central cause.
In a way, the soda industry wishes it were so. If a reduction in sugared soft drink consumption were the quick fix to the obesity problem, soft drink marketers and bottlers could be very effective, not to mention very successful, in solving the problem. For example, more than 50 percent of my own company's output is zero-calorie soft drinks, reduced-calorie juices, and teas, seltzers, sports drinks (which have less sugar and fewer calories than soft drinks) and good old water. These are our fastest-growing beverage categories.
However, there is no quick fix. The actual causes of obesity in both children and adults have been frustratingly elusive, especially for a condition that seems so straightforward and intuitive: We are overweight because we eat too much.
Turns out things aren't so simple. Consider that individual daily caloric intake has barely changed over the past 20 years. Researchers at the University of North Carolina studied 20 years' worth of federal dietary data and found that childhood obesity rates went up 10 percent but caloric intake rose only 1 percent. What changed was the exercise factor. Children's activity levels declined by a dramatic 13 percent.
So does this mean that the consumption side of body metabolism -- what we eat -- is entirely off the table, and it's all about human activity levels? Of course not, but it's a matter of balance and moderation.
Because some contend that obesity rates and soft drink consumption escalated at about the same magnitude in about the same period, some nutrition investigators have hypothesized that there is a connection. They set up research projects to test the hypothesis.
To date, not one of these projects has substantiated the theory that sweetened soft drinks are the central cause of the heavier weight of Americans.
The National Institutes of Medicine reviewed 279 nutrition studies and concluded there is no association between added sugars in diet and a person's body mass index. Even Dr. David Ludwig, head of a youth obesity program at Boston's Children's Hospital, who has called publicly for sin taxes on snacks and soda, acknowledges: "There is no clear evidence that consumption of sugars per se affects food intake in a unique manner or causes obesity."
Further, the federal Centers for Disease Control has said: "There are no data from the (Ludwig) study that allow us to make an estimate of what proportion of obesity might be accounted for by changes in soft drink consumption."
So the hypothesis that soft drinks are a cause of, or even the cause of, obesity remains unproven. Yet some activist nutritionists are impatient to get out in front of the hard research by insinuating -- because they can't prove it -- that soda is making us fat.
This is a disservice both to science and to society, particularly in light of a recent Harvard snack food research project. The study of more than 14,000 girls and boys that found that snack foods, including sugar-sweetened beverages, are not an independent determinant of weight gain in children and adolescents.
No one is selling soda as a health food, but neither is it "liquid candy," the spurious label served up by the Center for Science in the Public Interest. One can of regular soda has a so-called energy density (calories divided by weight) of 0.4 -- slightly less than orange juice or one percent milk. Nutritionists consider an energy density of 1.5 to be low and greater than 4.0 to be high.
In contrast, the energy density for candy varies, but two pieces of flavored hard candy is 3.9, candy bars are 4.6 to 5.6, one fourth of a cup of dry roasted peanuts is 5.9, two homemade chocolate chip cookies are 4.6 and a small order of fries would be 3.0.
Regular soft drinks are enjoyed for refreshment by millions of Americans with no adverse effect to their weight. Soda is neither the smoking-gun cause of obesity among Americans nor the silver-bullet cure.
Ralph Crowley Jr. is President/CEO of Polar Beverages Inc. (www.polarbev.com), Worcester, Mass., and also is chairman of the American Beverage Assn. (www.ameribev.org), formerly the National Soft Drink Assn. This article first appeared in the Boston Globe on Dec. 28, 2004.