Are artificial sweeteners a healthy substitute for sugar?

Anthony Komaroff, MD

Editor in Chief, Harvard Health Letter

When sugar-free beverages first became available, I was skeptical that they could really taste as good as “the real thing.” I quickly changed my mind. In fact, it seemed to me that the sugar-free versions actually tasted better than “the real thing.”

It seemed like a no-brainer. Sugar-free beverages had no calories and tasted better—maybe there is such a thing as a free lunch. Obviously, many people who also wanted to lose weight made the same switch. Were we right about artificial sweeteners?

Although short-term studies suggest that switching from sugar to no-calorie sweeteners can help, other research suggests it may actually promote weight gain. Writing in the December 2011 Harvard Health Letter, noted obesity researcher Dr. David Ludwig explores the possible connection between sugar substitutes and weight gain.

The FDA has approved six calorie-free sweeteners: acesulfame, aspartame, neotame, saccharin, Stevia, and sucralose. They are hundreds to thousands of times sweeter than table sugar. It is possible that people who routinely use them may wind up desensitized to sweetness.

Healthful, satiating foods that are less sweet—such as fruits and vegetables—may become unappetizing by comparison. As a result, the overall quality of the diet may decline. The calories removed from the diet by the sugar-for-sweetener swap may sneak back in, in the form of refined carbohydrates and low-quality fats.

Another concern is that sweetness receptors have been identified in fat tissue. “That raises the possibility that artificial sweeteners could cause weight gain by directly stimulating the development of new fat cells,” says Dr. Ludwig, a professor of pediatrics at Harvard-affiliated Children’s Hospital Boston, in the Health Letter article.

Dr. Ludwig’s research group is conducting a year-long trial in young adults to explore how artificially sweetened drinks affect weight and risk factors for heart disease compared with sugar-sweetened and unsweetened drinks. (If you are interested in taking part, call 617-355-2500.)

Dr. Ludwig’s bottom line? Use artificial sweeteners only for a while to help wean yourself off drinking sugary beverages.  That’s not my bottom line—yet.  But if the studies indicate that it should be, I’m prepared to change my mind.

You can read the full article on the Harvard Health website.

The Harvard Health Letter is a general interest health and medical newsletter published monthly by Harvard Medical School.

Related Information: Harvard Health Letter


  1. Anonymous

    I concur with your conclusions.The point that the data stated are all first hand on actual experiences even help more.

  2. srikar

    Anything artificial always comes with a catch,be it artificial sugar or some sort of weightloss pills.

    Diet is and always has been quite overrated …why not go for a walk or spend 30 mins a day working out instead of eating and drinking food that isnt natural ?

  3. hava

    I did not know royal sweeteners may cause weight gain, I Mstst them for a long time and a number of reasons among them diabetes, and obesity, I’ll try to get a dose.

    Thank you

  4. Anonymous

    I think artificial is fine it is just the cool thing to do now to be 100% natural. Of course natural is better but using artificial sweetner isn’t going to kill you haha. But seriously good read. I’m finding this whole blog really useful. Is it fan by actual professors by chance?

  5. Prodivita

    There’s always a new study concerning artificial sweeteners. In the EU recently there was – again- a study about possible cancer and aspartame. Again aspartame is believed to be “no risk to the common health”. I also read the article about weight gain caused by sweeteners. We have a weight loss company in belgium. Because of the lack of calories we use acesulfame and aspartame in our products. We regularly receive questions about the artificial sweeteners, also about Stevia lately. If these kind of sweeteners are bad why does our, and your government allow these? Now somebody tells us sweeteners are a possible source of weight gain…. Does somebody else knows something bad about artificial sweeteners? Please send your clinical trial request to Dr. David Ludwig and start a new mass hysteria. It’s always something…..

  6. Anonymous

    I had the knowledge that the artificial sweeteners were only made for the diabetic patients instead today through media it has been identified that through a sweetener one can even loose weight. But frankly speaking I am not in favor of using a sweetener neither for cutting wait nor for lessening sugar. If one is seriously looking for losing some wait then there is nothing better than exercise and fir diabetes the same formula can be applied. What say?

  7. Brooke

    Isn’t aspartame supposed to be dangerous though?

  8. Theresa, RD

    A long term Harvard study found that the use of aspartame helped people lose weight and keep it off. Research has also found that those who use low calorie sweeteners have better quality diets than those who don’t, i.e., consume less calories, fat, and added sugar, while getting higher levels of vitamins and minerals and eating more dark green and yellow vegetables. I am not aware of any scientific evidence to support your suggestion that people who habitually use low calorie sweeteners may become desensitized to sweetness. High intensity sweeteners are much sweeter than sugar, so extremely small amounts are used to achieve the same level of sweetness.
    Theresa Hedrick, MS, RD, LD
    Calorie Control Council

  9. Thomas

    Sweetening agents were always a better choice for me, but I don’t use them much, I try to cut the taste as much as possible from my diet. It was tough to swallow black coffee without any sweet taste in it. Now I’m used to it. I try to avoid both real & artificial sweetener.


  10. James Trevor

    If you’re trying to reduce the sugar and calories in your diet, you may be turning to artificial sweeteners or other sugar substitutes. You aren’t alone. The popularity of artificial sweeteners and other sugar substitutes is on the rise as manufacturers and consumers seek lower calorie alternatives to regular white sugar without sacrificing sweetness.

  11. Neu Life Chiropractic

    Many artificial sweeteners are not healthy for diabetics. Some of them can raise insulin rather than blood sugar levels. Insulin levels are not checked as often. Xylitol is safe for diabetics.

  12. Hannah

    Artificial sweeteners are made for diabetic persons and not for loosing weight. If somebody wants to loose weight, he should eat healthy and do some sports and should not try to loose it with the usement of artificial sweeteners.

  13. emedicalpoint

    Artificial sweetness is always artificial, we should try to avoid any type of artificial su1ar. A diabetes man should use limited sugar instead of artificial sweetness.

  14. arnold

    Not much of a distinction here between the NASSTYness of aspartame, saccharine and the like, when compared with the vastly (from what I can tell)less harmful properties of stevia.

  15. jmf2060

    Not much of a distinction here between the NASSTYness of aspartame, saccharine and the like, when compared with the vastly (from what I can tell)less harmful properties of stevia. Useful stuff about the sweetness receptors though.

  16. Dr.SubhashDabir

    Sweetner use may cause weight gain.I Want to know whether it raise the blood sugar level if consumed in excess by a diabetic person?

  17. Naomi

    Ah I have always been skeptical of sugar fraud!

  18. shriba

    This is a health blog written by a doctor? And you’re blogging about flavor? Your not Emeril, that’s not your job. How about getting people off the processed sugars to begin with, instead of turning them on to chemical laden substitutes? Shame on you. Harvard sure just went down a few notches. Good grief!

  19. tom@morethanpepper

    ah the confusing world of sugar

Commenting has been closed for this post.