INtake

Artificial intelligence
New research reports that consuming sugar-free fare may hurt in the long run.
By Kimiko L. Martinez
kimiko.martinez@intakeweekly.com

Thought sugar-free diet drinks would help you lose weight? The July issue of Self magazine features a Purdue University study that suggests -- of all horrors -- that eating too many "fake" sweets (foods sweetened with artificial sweeteners) might throw off your body's natural ability to count calories.

The gist: If you eat something with real sugar, your body naturally accounts for that sugar's calories. If you eat something with artificial sweetener, your body doesn't get the calories it expects. So it may trick you into overindulging in the real sweet stuff later.

We asked associate professor Susan Swithers, who researched and published the study "A Pavlovian Approach to the Problem of Obesity" with professor Terry Davidson at Purdue to explain what this diet dilemma means for everyday dieters.

In layman's terms, how does this affect us?

It may be that the body has some processes that allow us to learn that the tastes of foods mean calories. This kind of learning could help us to regulate our food intake, and, ultimately, our body weights. If we can't learn this, for example, if we consume foods that are sweet, but have no calories, we may have to use other types of methods to regulate, such as counting calories.

So, we shouldn't eat sugar-free items at all?

It doesn't necessarily mean that people should avoid sugar-free items. Instead, it may mean that if we're consuming foods that have a lot of taste, but not a lot of calories, that we might have to pay more attention to the items we consume that do have calories. So if people have a diet beverage, they should make sure that they aren't later overdoing it by eating foods that have lots of calories.

This study was more about obesity and possible causes, but why did you study sugar-free foods?

We've known for a while that animals, including people, can learn about what happens after we eat foods. Sometimes, that learning helps us avoid eating things that could be harmful to us.

But we also wondered whether this type of learning could also help us keep track of our food intake by predicting how many calories foods usually have before waiting for our bodies to absorb the calories. So, it made sense to think about the idea that it could be a problem if the tastes of foods were no longer predictors of calories.

We could be removing one of the mechanisms that we use unconsciously to regulate, and that may contribute to the increasing levels of overweight and obesity.

Anything else you'd like to add?

Our problems of obesity don't have a single, simple cause. There are probably lots of things that are contributing, including decreases in the amount of physical activity, increases in the availability of foods, portion sizes and many others.