人工甘味料で体重増

Sugar Substitutes May Contribute to Weight Gain

砂糖の代用品体重増に寄与

Surprising research suggests a popular artificial sweetener has the unexpected and unwelcome effect of packing on the pounds.

驚くべき調査は、一般的な人工甘味料には体重増になる予想外の歓迎されない作用があることを示唆しています。

Purdue researchers report that saccharin altered the ability of rats to control their appetites. However, the head of an artificial sweetener trade group scoffed at the findings, saying they don't necessarily translate to humans.

パデュー大学の研究者は、サッカリンがラットの食欲制御能力を変更させたと報告しています。しかし、人工甘味料業界団体の幹部は、必ずしもヒトに適用するわけはないと言って、をあざ笑った。

"We found that the rats that were getting artificially sweetened yogurt gained more weight and ate more food," said study author Susan Swithers, an associate professor of psychological sciences at the Ingestive Behavior Research Institute at Purdue University. "The take-home message is that consumption of artificially sweetened products may interfere with an automatic process."

「人工的に加糖したヨーグルトを摂取していたラットはより多く体重が増えて、より多く摂食したことを発見した」と、パデュー大学、摂食行動研究所、心理的科学の準教授の研究著者、Susan Swithersが言った。「お伝えしたいことは、人工甘味料の摂取は自動プロセスを妨げる可能性があるということです。」

That process, she said, involves the body's ability to detect that it will soon be full. "We often will stop eating before we've been able to absorb all of the calories that come from a meal. One of the reasons we might stop eating is that our experience has taught in the past that, 'After I eat this food, I'll feel this full for this long,' " she explained.

彼女が述べたそのプロセスはもうすぐ満腹になることを感知する身体能力を含みます。「食事由来の全てのカロリーを吸収することができる前に摂食を止めることが多いです。摂食を止めることになる理由の一つは、我々の経験が過去にそのことを教えたことであります。それはこの食事を食べた後に長い間これで満腹を感じると」彼女は説明した。

It seems to be a subconscious process based on automatic estimations of how much energy certain foods will provide, she said. For example, a sweet taste might be a sign that "calories are coming, and I should prepare my body for the arrival of those calories." However, when the sweetness is not followed by a lot of calories, the body's digestive system gets confused, and the metabolism rate does not gear up as much the next time sweetness is tasted.

特定食品がどの位のエネルギーを供給するかの自動的に概算することに基づく無意識プロセスであるようであると、彼女は述べた。たとえば、甘味は、カロリーが来るとのサインであるかも知れなくて、これらのカロリー到着に対して私の体は準備しなければならない。しかし、甘味が多くのカロリーを伴わないと、身体の消化器系は混乱をきたして、次の甘味が感じられるほど代謝率が上がってこなくなる。

To test this theory, the researchers fed two different types of plain Dannon yogurt to male rats. Some received yogurt sweetened with glucose, a form of sugar, while others ate saccharin-sweetened yogurt. All also ate unsweetened yogurt.

The rats who ate artificially sweetened yogurt consumed more food overall and gained more weight. The body temperatures of those rats also didn't rise as high as the others. "That might be a kind of measure of energy expenditure, suggesting not only are the animals eating more calories, they may be expending or burning up fewer calories," Swithers said.

The findings were published in the February issue ofBehavioral Neuroscience.

Essentially, she said, it appears that the bodies of the rats are learning to not expect much in the way of calories from sweet foods. "The artificial sweetener provides the signal that not as many calories are going to come, and the animal responds by consuming more calories."

As for humans, she said, previous research has provided conflicting indications about whether obesity is a bigger problem among people who use artificial sweeteners.

According to her, launching a similar study among people would be difficult, because few have never encountered artificial sweeteners before. The next step, she said, is to do more research in rats.
Lyn Nabors, president of the Calorie Control Council trade group, lambasted the study, saying it has "no basis in science" and "no relation to the human experience whatsoever."

Artificial sweeteners can help people lose weight, she said. "The scientific community firmly believes that calories in, calories out is what makes a difference. The recommendation is that you reduce calories and exercise if you want to lose weight."