Do Diet Sodas Cause Weight Gain?


diet soda weight gainStudy Finds Sweeteners May Raise Blood Sugar By Changing Gut Bacteri

debate over sugar substitutes started with the invention of saccharin 135 years ago.  President Theodore Roosevelt’s own doctor recommended replacing his dietary sugar with saccharin for weight loss.  

When an FDA commissioner, Harvey Wiley, spoke out against the artificial sweetener as a health hazard, Roosevelt retorted, “Anybody who says saccharin is injurious to health is an idiot.”

Since then, researchers have been studying the effects of artificial sweeteners on health. Like a pendulum, the results keep swinging between “helpful” and “hurtful.”

In a recent post about the great diet soda debate, we examined a study that suggested drinking diet soda could help you lose weight. Now a new study published in the journal Nature indicates that drinking diet sodas increase some people’s risk for developing metabolic disease such as Type 2 Diabetes and obesity because it changes the types of microbes that live in the intestinal tract.

New Research On Artificial Sweeteners In Diet Sodas

Initially, researchers at the Weizmann Institute of Science in Israel fed mice zero-calorie sweeteners (saccharin, aspartame, sucralose) and observed that they developed glucose intolerance. Then, to see if a similar phenomenon was happening to humans, they looked at data from an ongoing nutrition study.

They found that people who consumed a lot of artificial sweeteners has slightly higher HbA1C levels (a long-term measure of blood sugar) than those who didn’t consume artificial sweeteners.

In the next stage of the study, seven volunteers who didn’t regularly consume diet drinks were given the equivalent of 10-12 artificial sweetener packets for a week. Some of the volunteer subjects showed pre-diabetic spikes in their blood sugar levels after just a couple of days.

“What we find is that a subgroup [four of the seven people] developed significant disturbances in their blood glucose even after short-term exposure to artificial sweeteners,” said Weizmann researcher Eran Elinav. “This was a surprise to us.”

Weight Gain Due To Glucose Intolerance From Changes In Gut Bacteria

Reseachers saw that in both mice and people, ingesting artificial sweeteners caused certain types of gut bacteria called Clostridiales  to be eliminated and others — Bacteriodes — to flourish. While scientists are still just starting to understand how gut bacteria are related to health conditions, the pattern of too many Bacteroides and too few Clostridiales has been found in some people with diabetes.

“What was super-striking and interesting to us was that we could predict ahead of time (who would be affected by the sweeteners),” said Eran Segal, relating how two distinct patterns in the microbiomes of their volunteers enabled researchers to anticipate who would be affected by the sweeteners. “

Some Critics Have Soured On This Sweetener Study

The Israeli researchers and some in the news media have been quick to announce a hidden link has been uncovered between the artificial sweeteners in diet soda and obesity, but critics say that conclusion is a stretch and not supported by recent obesity research.

“It’s true that the prevalence of obesity and diabetes started shooting upward in the early 1980s, along with skyrocketing consumption of diet soda (brought on by the introduction of aspartame-sweetened Diet Coke). The researchers cite this overlap to support the claim that fake sugar makes us fat. More recent data suggest the opposite, however.

The last decade has seen a leveling off of obesity rates, at least in terms of BMI, while the use of non-caloric sweeteners has dramatically increased over the same period, especially among children and adolescents. Meanwhile, white people—both adults and children—consume, on average, twice the volume of diet beverages as black people, though obesity rates are much higher among the latter.

Do Diet Sodas Cause Weight Gain?

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Critics of the study also point out that a) seven human volunteers is an inadequate cohort and b) the researchers focused on the oldest and least commercially used sugar substitute — saccharin — because it had the most acute effect on the mice.

A large-scale human study would be needed before making a definitive causal link between artificial sweeteners and glucose intolerance, and then that still wouldn’t necessarily prove that sugar substitutes cause obesity.

The diet soda debate rages on! What do you think? Take our poll.

One response to “Do Diet Sodas Cause Weight Gain?”

  1. judy says:

    I’d like to know who paid for this study. Probably some connection to the sugar industry.

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