Clifford S. Mintz Ph.D., author of Bio Job Blog, writes about a study suggesting that artificial sweeteners may cause people to gain rather than lose weight. Like Cliff, I had heard reports of this but never paid much attention. Although the study was published several months ago, I recently became interested in it because I am trying to kick a bad dependence on diet sodas.
Over the past few years, I have heard rumors that artificial sweeteners like saccharine, aspartame and sucralose actually cause people to gain rather than lose weight. I summarily dismissed these stories because they did not make sense to me nor did I think that they had any scientific merit-until today!
Purdue University psychologists Drs. Susan Swithers and Terry Davidson fed rats yoghurt sweetened with glucose (15 calories per teaspoon) or yoghurt containing the artificial sweetener saccharin (0 calories per teaspoon). Rats that were fed the saccharin-sweeten yoghurt subsequently consumed more calories, gained more weight, put on more body fat and were unable to regulate dietary intake of calories as compared with rats that were fed glucose-sweetened yoghurt. The authors surmised that breaking the connection between a sweet sensation and high-calorie food, changes the body's ability to regulate caloric intake. This could partly explain why obesity has risen with the increasing use of artificial sweeteners in drinks. The study's findings are consistent with emerging evidence that people who drink more diet drinks are at higher risk for obesity and development of the metabolic syndrome that increases the risk for heart disease and diabetes.
So, how do the authors explain their seemingly paradoxical findings? Swithers and Davidson postulate that ingestion of sugar-rich (sweet) foods provides a 'salient orosensory stimulus" that signals that the body is about ingest a lot of calories. This, in turn, induces the body to physiologically-prepare itself for ingestion of a high calorie meal. However, when the false sense of sweetness (provided by the artificial sweetener) is not followed by consumption of large amounts of calories, the system gets "confused"- causing people to eat more or expend less energy to account for the calorie imbalance. Nevertheless, the good news is that people who use artificial sweeteners can still count calories to regulate caloric intake and body weight. Unfortunately, as the authors suggest, counting calories requires a more conscious effort and a lot more work than routinely consuming low-calorie foods.
Although this study was conducted in rats, its findings are consistent with the observations that increased use of artificial sweeteners can contribute to human weight gain. Despite the study's findings, similar experiments must be conducted in people to substantiate or refute the authors' hypothesis.
More about Cliff Mintz: Cliff has an extensive background in biopharmaceutical training and science career development. He has been a management consultant to a number of emerging and publicly-traded biopharmaceutical companies. Cliff has also held a variety of positions including stints as a medical school professor, professional recruiter, and medical/science writer.
(All excerpts used with permission.)
I suppose this would be particularly pertinent to those people who go to McDonalds and order "a BIG mac, LARGE fries...and DIET coke!"
Karen, I am also trying to kick my addiction to diet drinks and artificial sweeteners in general. It's hard though, because I have become so used to them that I can no longer take regular sugar (regular sugar doesn't taste sweet enough for me anymore-how sad).
Dear Karen and all,
Looking at the graphic pictures in this private study on aspartame should help the addiction which BTW is caused by the methanol (wood alcohol, a poison) highly addictive and 10% of the aspartame molecule.
Thanks for letting me post.
I guess I would ask first why you consider diet drinks "bad?" How scientific is your reasoning, or is it based on a perception that they're bad for you? The results of this study are interesting, but I don't know that I'm convinced it shows conclusively that diet sodas cause you to gain weight. I've been drinking them for years, and I've maintained my weight. But I also watch everything I eat and try to get regular exercise. I'm not a scientist but I think those factors are key. From my own observations, some people drink diet sodas thinking it will help them lose weight. It can certainly reduce their caloric intake but it's only a drink. What else are they eating and how much exercise do they get? I've seen overweight people order a diet soda with a Big Mac. Um, what's the point?
I have two critiques of this report - one is methodological and one is anecdotal.
1) This study used a calorie-rich food (yogurt) as the variable in the report. To make the jump that diet sodas (that would be NO calories) are contributory to the obesity problem is a stretch. Why not feed the mice sugar water, saccharin water and unsweetened water???
2) I used to drink a lot of juice and regular soda. My wife helped me switch to water and diet soda. I lost 15 pounds without changing my moderate activity level and modestly healthy diet.
Just more food for thought...
The real issue we should be debating is why do we want to drink diet soda instead of water? Thats what I wanna know.
Something not mentioned is the difference between a semi-solid food [yogurt] and a purely liquid food. Studies of isocaloric liquid vs solid foods have had mixed results, with no differences in postprandial satiety in some showing higher satiety with solid foods. see here for instance. This could make your transfer from yogurt to sodas somewhat dicey.
BTW, there is more methanol in many fruit and vegetable juices than in an equivalent volume of aspartame sweetened beverages. However, most of the juices also contain more of the antidote to methanol poisoning - ethanol - while the artificially sweetened drinks have none. So ... rum and Diet Cokes all around.
I choose diet soda over water when I need caffeine. Coffee doesn't sit well with me, and my current situation in life demands more time alert and awake than I've been able to handle 'drug-free.'
Definitely one where more research is needed. Especially into why this happens in the body.
Riverwolf: I've seen overweight people order a diet soda with a Big Mac. Um, what's the point?
Sava: I suppose this would be particularly pertinent to those people who go to McDonalds and order "a BIG mac, LARGE fries...and DIET coke!"
The point is TASTE, not CALORIES. I cannot stand the taste of full-sugared sodas. To me, Diet Pepsi/Coke is MUCH better tasting than the non-diet variety. So, yes, I am one who will occasionally go into a fast food joint, and get a burger, fries, and a diet soda...
To get back on topic, I am a diet soda drinker, but I should probably be a no-soda drinker. Pick your poison: Aspartame or High Fructose Corn Syrup.
I think that ginen a choice, High Fructose Corn Syrup is safer than Aspertame. My real issue with these studies, or more correctly publications is that they are writtent to prove a point and this article like many others does not provide enough solid evidence to prove its point.
They do nothing more than tricking your mind into thinking you are having something sweet, you will just want more and more of the sweet sugary things, even worse, more of the aspartame that causes cancers and tumors.