March 7, 2006
By Michael Siegel

An Associated Press article that appeared in many newspapers nationwide this Sunday explains how efforts to research and fight obesity in this country seem to be focusing on soda as the cause of the problem and as the chief target of public health action.

According to the article: "In reports to be published in science journals this week, two groups of researchers hope to add evidence to the theory that soda and other sugar-sweetened drinks don't just go hand-in-hand with obesity, but actually cause it." ...

"A small point? In reality, proving this would be a scientific leap that could help make the case for higher taxes on soda, restrictions on how and where it is sold -- maybe even a surgeon general's warning on labels."

"'We've done it with cigarettes,' said one scientist advocating this, Barry Popkin at the University of North Carolina in Chapel Hill. Comparing soda and obesity to tobacco and lung cancer is a baseless crusade, industry spokesmen say. 'I think that's laughable,' said Richard Adamson, a senior science consultant to the American Beverage Association. Lack of exercise and poor eating habits are far bigger contributors to America's weight woes, he said." ...

"'There are many different lines of evidence, just like smoking,' said Dr. David Ludwig, a Harvard pediatrician who wants a "fat tax" on fast food and drinks."

One of the lines of evidence indicting sodas that appears in the article is that drinking soda causes poor nutritional intake in other ways: "Sugar-sweetened beverages affect the intake of other foods, such as lowering milk consumption. Popkin contends they also may be psychological triggers of poor eating habits and cravings for fast food. He examined dietary patterns of 9,500 American adults in a federal study from 1999-2002. Those who drank healthier beverages — water, low-fat milk, unsweetened coffee or tea — were more likely to eat vegetables and less likely to eat fast food. Conversely, 'fast-food consumption was doubled if they were high soda consumers, and vegetable consumption was halved,' he said. Harvard epidemiologist Eric Rimm saw a similar effect in a different federally funded study of more than 5,000 young adults. With high soda consumption, 'you see this pattern of less-healthy intake across the board,' he said at the obesity meeting."

The Rest of the Story

Well of course you see less healthy intake of food and drink in persons who have high soda consumption. And of course people who drink healthier beverages like water and low-fat milk are more likely to eat vegetables and less likely to eat fast food. It doesn't take rocket science to figure out that people who drink a lot of soda are, in general, going to have poorer overall nutrition than those who drink a lot of water, unsweetened tea, and skim milk.

When was the last time you saw a guy guzzle down 3 cans of beer while munching on a modest portion of Wheat Thins? And when was the last time you saw someone drinking skim milk to wash down a hefty serving of Hostess Twinkies?

But that is exactly the point. Drinking a lot of soda is simply a marker of poor overall nutrition. And it is poor overall nutrition (combined with insufficient exercise and physical activity) that is responsible for obesity, not any singular effect of soda, or any other particular food or drink item for that matter.

It appears to me that the fervor to make this analogy between obesity and tobacco-related disease has resulted in an overly simplistic view of this public health problem that is spawning a framing of the issue that is destined for failure.

While I don't generally agree with much of what the food industry has to say (although I concede the general point that Almond Joy has nuts and Mounds don't), I do agree with the beverage industry spokesperson who suggested that comparing soda and obesity to tobacco and lung cancer is a baseless crusade.

First of all, while tobacco can be a singular cause of lung cancer (i.e., you can get lung cancer merely from smoking), soda is not a singular cause of obesity. For people who drink a lot of soda but otherwise are careful about their nutrition and who also get sufficient exercise, obesity is not a problem. In other words, soda in and of itself does not cause obesity. It cannot do it alone. Unlike cigarettes.

Second of all, there is not really a healthy level of cigarette consumption. It's not the case that smoking 1/2 pack of cigarettes per day is perfectly healthy but one or more packs per day is harmful. In contrast, if you drink soda in moderation you will not suffer any health impacts.

Third of all, cigarettes are addictive and contain a psychoactive chemical that crosses the blood-brain barrier, a chemical whose level in cigarettes if finely controlled by the manufacturer to enhance addiction. While caffeine has some addictive qualities, it is not at all addictive on the scale of nicotine.

Fourth, smoking is one of only a few exposures that cause lung cancer. Approximately 85% of lung cancer cases are directly attributable to cigarettes. But it is unlikely that any cases of obesity can be directly attributed solely to soft drinks. There are a host of exposures that contribute, in a multi-factorial way, to cause obesity.

It is convenient to pick a scapegoat upon which to blame the nation's obesity problem because it avoids a lot of the difficult work that needs to be done. Singling out soda makes it easy. We just treat soda like cigarettes. Tax it to death. Put a stigma on its use. Put warning labels on it.

But such an approach would take the focus off the real problem: the political, economic, geographic, social, and cultural factors that contribute to poor nutrition and to a dismal lack of adequate physical activity, which combine to create conditions in which caloric intake greatly exceeds caloric expenditure for a majority of the population.

While I am not arguing that soda consumption should not be addressed as part of any larger solution to the obesity problem, I do not see any wisdom in making it the focus of our efforts. But I do see the potential for a lot of damage. Namely, it will likely create a distraction from the larger problems that need to be addressed.

It's just not as simple as putting a tax on soda and a warning label on Coke and Pepsi. It's not as simple as suing soda manufacturers for selling their products to kids in schools and causing children to become obese.

In fact, even if soda were to be completely banned today, I doubt that the obesity problem would be solved. You have to drink something, and with poor nutritional habits, kids would likely substitute other high-calorie drinks for the soda.

If you walk around Boston, the first thing you may notice is that food choices are not equally distributed geographically. The poorer neighborhoods simply do not have access to highly nutritious food choices. Just compare Roxbury and the Back Bay. It's easy to eat healthy in Back Bay. Not so easy in Roxbury. And putting warning labels or high taxes on soda simply isn't going to solve that problem.

And we live in an era where kids can get all the entertainment they want just sitting around a television set. When I was a kid, we just had Atari. But how many games of Breakout could you play before you needed to go outside and run around? Now, you've got Game Boy, Nintendo, Game Cube, Play Station, Play Station 2, XBox, and XBox 360: hours of entertainment and you don't have to leave the comfort of your own living room. And that's before you even consider computer games, chatrooms, or reading and commenting on blogs of all things.

Singling out soda may make addressing the obesity problem easy, but it doesn't make it effective. And I think the danger is that this approach threatens to distract attention from the complex, multifactorial nature of the problem and the many avenues that must be addressed to tackle it effectively.

I think the analogy to tobacco was perhaps the worst thing that could have happened to the obesity control movement. They are just not the same type of problem, and shouldn't be treated that way.