Artificial sweetners / diet sodas linked to obesity

[KurtNYC]

This is terrible news for those who drink diet soda to avoid calories. A study at Purdue University indicates that the body's ability to correctly perceive the amount of calories being consumed from all foods is severely impaired by consuming artificial sweetners like the ones in Diet Coke.

Professor Terry Davidson and associate professor Susan Swithers, both in the Department of Psychological Sciences, found that artificial sweeteners may disrupt the body's natural ability to "count" calories based on foods' sweetness. This finding may explain why increasing numbers of people in the United States lack the natural ability to regulate food intake and body weight. The researchers also found that thick liquids aren't as satisfying – calorie for calorie – as are more solid foods.
...
"The body's natural ability to regulate food intake and body weight may be weakened when this natural relationship is impaired by artificial sweeteners," said Davidson, an expert in behavioral neuroscience. "Without thinking about it, the body learns that it can use food characteristics such as sweetness and viscosity to gauge its caloric intake. The body may use this information to determine how much food is required to meet its caloric needs."
...
Incidence of overweight and obesity has also increased markedly during this period," she said. "Our hypothesis is that experience with these foods interferes with the natural ability of the body to use sweet taste and viscosity to gauge caloric content of foods and beverages. When you substitute artificial sweetener for real sugar, however, the body learns it can no longer use its sense of taste to gauge calories. So, the body may be fooled into thinking a product sweetened with sugar has no calories and, therefore, people overeat."

http://www.sciencedaily.com/releases/2004/06/040630081825.htm

This research fits with some statistical analysis more recently released.

Just when you thought the news about losing weight couldn't get any worse, try this: A review of 26 years of patient data found that people who drink diet soft drinks were more likely to become overweight.

Not only that, but the more diet sodas they drank, the higher their risk of later becoming overweight or obese -- 65 percent more likely for each diet drink per day.
...
Drinking any soda -- regular or diet -- was linked to a higher risk of becoming overweight. But when the researchers adjusted the data to account for differences in age, sex and ethnicity, they found that regular soft drinks had very little connection with serious weight gain.

Diet drinks, however, did.

http://www.indystar.com/apps/pbcs.dll/article?AID=/20050615/LIVING/506150307/1079/ENTERTAINMENT02

Like HFCS, this seems to be another way that artificially created foods impair health. We could all save some money and frustration by replacing soda, both diet and HFCS-based, with water.

[kick-ass-bob]

1. Are they sure they have the cause and effect correct?

Could it be that people get a Supersized Big Mac meal with a Diet Coke?

Just askin...

[Telly Savalas]

4. Read the articles.

The scientists who did the study in the second link freely concede the possibility that the causality might work in either direction. The study in the first link, however, gives a viable explanation as to why artificial sweeteners can contribute to weight problems. The study on rats they performed suggests that there's something to their theory.

[Dogmudgeon]

2. That's going to need some serious replication

The implications are obvious -- the only way to lose weight effectively will be to drink a lot of fluid with a bitter or nauseating flavor.

--p!

[Coastie for Truth]

3. An anecdotal observation

My Mom - a cantankerous curmudgeon 93 year old retired "MSN Nursing School Professor" chuckled and said "I've been saying that for 70 years and I'm not a fancy MD" when I read this append to her.

She has always stubbornly insisted that diabetics and obese people who use artificial sweeteners don't have any idea of their calorie intake -- and that the situation is aggravated by artificial sweeteners.

As would be expected - her favorite Presidents were Harry Truman and Bill Clinton.

[SnowGoose]

5. Epidemiology's biggest handicap

is that it proves "association" and not "causation" (There are some caveats with that statement, but they're a bit obscure for this discussion).

One little scenario: overweight people know they're overweight, and most will try to do at least a little something about it. An easy something - one that doesn't require a lifestyle rearrangement - is to order diet pop with your meal rather than regular pop. *poof* Now you have a population that will (in the aggregate) display a tendency for the overweight people to be drinking diet soda, and those without a weight problem to be drinking regular soda.

To a statistician's eyes, you've now got a statistically significant association between obesity and consuming diet soda. But not necessarily because the diet soda is *causing* the obesity.

Epid papers need to be read very carefully - and it pays to remember that you're not looking at a biology paper, but a paper on statistical characteristics of a population.

That doesn't *disprove* the assertion, but may be a useful grain of salt to include.

[KurtNYC]

7. That's a good point

The second citation above is just statistical correlation. But the data showed that the more cans of diet soda consumed per day the higher the chance of being obese later. Since diet soda contains zero calories it shouldn't matter how many were consumed but the data shows strongly (a 65% increase for each can per day) that it does. If the correlation was only between a conscious decision to avoid calories (thus choosing diet sodas) and becoming overweight then the amount consumed would have no impact. But if we are observing the effects of artificial sweetner on the ability of the body to regulate itself then the amount consumed does matter. In other words the more you consume, the less able your body is to regulate intake/weight.

However the first is a controlled study designed to isolate the cause and effect relationship.

There are more studies out there, one of which seems to show that artificial sweetners fake out the body and actually make people crave sweet foods.

[Taverner]

6. I think the part to read is right here:

"Incidence of overweight and obesity has also increased markedly during this period," she said. "Our hypothesis is that experience with these foods interferes with the natural ability of the body to use sweet taste and viscosity to gauge caloric content of foods and beverages. When you substitute artificial sweetener for real sugar, however, the body learns it can no longer use its sense of taste to gauge calories. So, the body may be fooled into thinking a product sweetened with sugar has no calories and, therefore, people overeat."

So the moral of the story? Don't overeat.

Again, its correlation and causation being confused.