THERE’S NO DOUBT about it. Artificial sweeteners cause obesity.
I always thought it was funny to see a very large person order a Big Mac, large fries — and top it off with a Diet Coke. I also found it peculiar that I rarely saw thin people drinking diet sodas. So I began to wonder if there could be a link between diet beverages or artificial sweeteners and obesity. As I began to explore this notion, I discovered a number of different research findings that pointed to this very phenomenon.
First, our current obesity epidemic has coincided perfectly with the introduction of large amounts of artificial sweeteners into our food supply. Although we cannot say for sure that this means artificial sweeteners cause obesity, it certainly makes me wonder.
Next, a body of research indicates that just the thought or smell of food initiates a whole set of hormonal and physiologic responses that get the body ready for food. This is familiar to us from Pavlov’s dog experiment, where he trained dogs to salivate by associating the ringing of a bell with the presentation of food.
By doing this repeatedly, he eventually trained the dogs to salivate in anticipation of food simply by ringing the bell – without any food at all.
Think of diet sodas and artificial sweeteners as ringing the bell for your physiology. Today I will explain how that happens and review some of the research that indicates artificial sweeteners may not be all they are cracked up to be.
Stop confusing your body. If you have a desire for something sweet, have a little sugar, but stay away from “fake” foods.
The Problem with Ringing Your Physiological Bells
Ringing the bells in your body with artificial sweeteners is not a good thing. It’s even worse when you ring the bells with artificial sweeteners and then not provide any sugar. Here’s why …
Our brains know how to get our bodies ready for food. It is called the cephalic (for “head”) phase reflex. Your brain is preparing for food even before your fork or cup crosses your lips. This allows you to anticipate and prepare for the arrival of nutrients in your intestinal tract, improves the efficiency of how your nutrients are absorbed, and minimizes the degree to which food will disturb your natural hormonal balance and create weight gain.
So, in a way, your body is already preparing to regulate your energy balance, metabolism, weight, calorie burning, and many other things – just by thinking about food. Any sweet taste will signal your body that calories are on the way and trigger a whole set of hormonal and metabolic responses to get ready for those calories.
When you trick your body and feed it non-nutritive or non-caloric sweeteners, like aspartame, acesulfame, saccharin, sucralose, or even natural sweeteners like stevia, it gets confused. And research supports this.
Studies Show Artificial Sweeteners Lead to Weight Gain
An exciting study in the Journal of Behavioral Neuroscience has shown conclusively that using artificial sweeteners not only does not prevent weight gain, but induces a whole set of physiological and hormonal responses that actually make you gain weight. ( i)
The researchers proved this by giving two different groups of rats some yogurt. One batch of yogurt was sweetened with sugar. The other was sweetened with saccharin. They found that three major things happened over a very short period of time in the rats that were fed artificially sweetened yogurt.
First, the researchers found that the total food eaten over 14 days dramatically increased in the artificial sweetener group — meaning that the artificial sweetener stimulated their appetite and made them eat more.
Second, these rats gained a lot more weight and their body fat increased significantly.
And third (and this is very concerning) was the change in core body temperature of the rats fed the artificial sweeteners. Their core body temperature decreased, meaning their metabolism slowed down.
So not only did the rats eat more, gain more weight, and have more body fat, but they actually lowered their core body temperature and slowed their metabolism. As I have said many times before, all calories are not created equal …
The most astounding finding in the study was that even though the rats that ate the saccharin-sweetened yogurt consumed fewer calories overall than the rats that ate the sugar-sweetened yogurt, they gained more weight and body fat.
These findings turn the conventional view that people will consume fewer calories by drinking artificially sweetened drinks or eating artificially sweetened foods on its head. Despite their name, these are not “diet” drinks. They are actually “weight gain” drinks!
We’re surrounded by low-calorie, “health conscious foods” and diet soft drinks that contain sweeteners. As a result, the number of Americans who consume products that contain sugar-free sweeteners grew from 70 million in 1987 to 160 million in 2000.
At the same time, the incidence of obesity in the United States has doubled from 15 percent to 30 percent across all age groups, ethnic groups, and social strata. And the number of overweight Americans has increased from about 30 percent to over 65 percent of the population. The fastest growing obese population is children.
Here’s the bottom line: Avoid artificial sweeteners, including aspartame, acesulfame, sucralose, sugar alcohols such as malitol and xylitol (pretty much anything that ends in “ol”), as well as natural artificial sweeteners like stevia.
Stop confusing your body. If you have a desire for something sweet have a little sugar, but stay away from “fake” foods. Eating a whole-foods diet that has a low-glycemic load and is rich in phytonutrients and indulging in a few real sweet treats once in a while is a better alternative than tricking your body with artificial sweeteners – which leads to wide scale metabolic rebellion and obesity.
So, put that teaspoon of sugar in your tea and enjoy!
Now I’d like to hear from you…
Do you use artificially sweetened products?
How have they affected your weight?
What sweet treats do you indulge in?
Has this finding taken you by surprise?
Please leave your thoughts by adding a comment below – but remember, we can’t offer personal medical advice online, so be sure to limit your comments to those about taking back our health!
To your good health,
Mark Hyman, MD
References
(i) Swithers SE, Davidson TL. A role for sweet taste: Calorie predictive relations in energy regulation by rats. Behav Neurosci. 2008 Feb;122(1):161-73.
First of all, I don’t think using the word “funny” when referring to your response regarding large people who order Big Macs and fries and top off with a Diet Coke was a good choice of words. I think maybe sobering, or sad would be more appropriate. Second, I do agree that artificial sweeteners do increase appetite and contribute to weight gain, but for me Stevia does not do that. I don’t use a lot of it, just to sweeten my coffee or tea and I make a Cinnamon powder with the Stevia to put on toast occasionally. I am satisfied with Stevia, never get more hungry using it like other artificial sweeteners and SUGAR and have been losing weight using it. I am curious as to why you lump Stevia in with the artificial sweeteners when advising of their downfalls, could you please elaborate a bit on Stevia. Thank you.
I fully agree with Debbie regarding stevia. Dr. Hyman has advised against stevia in at least one of his books and that puzzled me as well.
And please let’s all try to be a little bit less judgmental about “large people.” My daughter has an adrenal disorder that caused a tremendous weight gain that results in all kinds of judgments and discrimination.
I was using lots of Stevia, and found that the more I used, the more I wanted…things didn’t taste “sweet enough”.. I couldn’t drop ANY weight..
I’m not on the Hyman diet…not using any artificial sweeteners, except for occasional Agave …I find that food tastes betters, I don’t crave sweets!! I’m still waiting for my weight to change, however……
Hi Victoria,
Thank you for yourinterest in Dr Hyman’s work. Even agave can lead to cravings and increase fat deposition. For more information check out http://www.bloodsugarsolution.com This program should help you kickstart the weight loss!
For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: http://www.bloodsugarsolution.com/nutrition-coaching/ OR call (800) 892-1443 to get started.
Sorry, Dr. H., but telling me to “have a little sugar” is like saying “have a little poison.” Even though I am only mildly hypoglycemic — as, I suspect, are many people — a little bit of white sugar sets off a chain reaction that I would rather not take up a lot of space describing. The craving may actually be for Vitamin C. Eating an orange, which contains natural sugar, fiber, and Vitamin C, usually satisfies my craving without thowing my system off balance for several days.
I use a lot of artificial sweetner, mostly aspertime. I use it in my food I prepare myself, sweetening plain yogurt, making small amounts of cocoa sauce to drizzle on fruit as a treat. I avoid the types of food that tend to have sugar in the recipe, unless it is a small amount to be used to balance the flavor profile. I have cut back on diet soda consumption, but not completely. I have lost 40 pounds and have managed to stay under or around my goal for two years. I don’t necessarily dispute the psychological effects of “sweet” items. and the lowering of body termperature is interesting finding, but I would like to understand the chemical disposition of artifical sweetners. How does the body process them?
In my opinion artificial sweeteners do not effect weight gain. I have been using artificial sweeteners now for 1 yr on my present diet. in my coffee, on my cereals and in my cooking and have lost 81lbs I have been able to cut my heart medications in half, increase the circulation (cardio-vascular) in my legs and have virtually eliminated my diabetes 2 by not using real sugar. I could never have accomplished this without the aid of artificial sweeteners. I get my sugar fix through fresh fruit. I do agree with the diet soda. I have stopped drinking diet soda and feel all the better for it. I have substituted non carbonated flavored sugar free drinks. By using a combination of artifcial sweeteners anf fresh fruit I continue to satisfy and calm my cravings. Thank you.
The reason I order a diet coke (which I stopped doing) is because I liked the taste better than regular coke. It had nothing to do with the calories. I agree… I think Stevia is very good to use instead of regular sugar. I’m one of those people that need 2-3 tsp. of sugar in my iced tea or cup of coffee, I would never use that much real sugar.
I use xylitol in my coffee and tea. I sip these beverages slowly over several hours and I love the fact that xylitol actually protects your teeth from decay. Also unlike the artificial sweeteners you list it does contain calories, but xylitol has a low glycemic index.
I personally can not stand the taste of artificial sweeteners or stevia.
Please explain how saccharin consumption produces elevated insulin. Thank you.
Hi Peter,
Thanks for your interest in Dr Hyman’s work. Have you read his new book, The Blood Sugar Solution? Excellent explanation found there too!
Check out this article for more info: http://drhyman.com/blog/2013/02/15/how-diet-soda-makes-you-fat-and-other-food-and-diet-industry-secrets/
Does this hold true for type 2 diabetics?
Hi Susan,
YES- For us all!
For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: http://www.bloodsugarsolution.com/nutrition-coaching/ OR call (800) 892-1443 to get started.
I, too was puzzled by Dr H’s advising of Stevia as a ‘natural artificial sweetener’ as according to a web page :-
“Stevia is an all natural kilojoule-free sweetener, stevia is a natural herb the South American native tribes have been using for generations. Botanically known as Stevia Rebaudiana, the glycosides in the leaves of the plant make it hundreds of times sweeter than sugar making it an attractive natural alternative to artificial sweeteners. It has no effect on blood sugar levels and contains a number of protecting and disease preventing phytochemicals.
Stevia is completely non-toxic and is and has been consumed in large quantities by several countries for many years without incident. Japanese manufacturers use stevia extensively in food products such as pickles, and soft drinks, as well as for general table use. Stevia is available from health food stores as it is considered a dietary supplement. ”
I will be very interested in a further explanation.
DR HYMAN, AS SOMEONE WHO HAS RESOLVED METABOLIC SYNDROME AND INTRACTABLE HIP PAIN FROM POLIO, BY ELIMINATING SUGAR, i would dissagree with your statements that artificials are worse and cause more weiight gain that sucrose>… i have lost 37 pounds and weight what i weighted in high school, and have subsituted sucralose for all process sugars, with results which have been totally durable for ten to fifteen years,! no hip pain and complete elimination of the symptoms of metabloic syndrome. so maybe the neurochemistry of rats is not as close as we think. in the face of all the people with diobesity, which you are the guru, leading the way to lifestyle as resolution for the billions with this disease and other metoblic risk, i still think “WHITE “IS THE TOXIN< AND THE CAUSE OF THE LIONS SHARE OF OUR OVERWEIGHT DISEASED WORLD …. APPRECIATE YOUR WORK LEADING THE WAY, JUST NOT SURE ABOUT THIS ISSUE, SINCERELY JOHN B STEVENS
Every day between breakfast and lunch I have with lemon from my tree and aspartame in a cup of tea. This keeps me going through the morning. I am 5 10 1/2 and weigh 127lbs.
Hi Sandy,
As you read in the article, aspartame is not suggested a healthy source of energy and actually may be quite harmful. Dr Hyman suggests balancing your blood sugar with protein-based meals made from whole foods. Please visit http://www.bloodsugarsolution.com to learn more!
For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: http://www.bloodsugarsolution.com/nutrition-coaching/ OR call (800) 892-1443 to get started.
All the way from South Africa!!! Dr Hyman what you said is so true, God Bless
Wondering what about Agave Nectar as a sweetener? My mother HAS to have her coffee and she was using aspartame, But when I told her no, she said Stevia. I told her just to put a little Sugar in her coffee..she says that sugar is too sweet for her. Does Agave Nectar fall in the same category?
Hi Lisa,
You are correct. If she needs a little sugar, use the real thing! We dont suggest agave nectar being any healthier than real sugar.
For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: http://www.bloodsugarsolution.com/nutrition-coaching/ OR call (800) 892-1443 to get started.