Do Artificial Sweeteners Help You Lose Weight?

Written by Dr. Steve Chaney on . Posted in artificial sweeteners and weight loss, Blood Sugar, Diet Soda and Health

Sucralose and Weight Loss

Author: Dr. Stephen Chaney

 

Do artificial sweeteners help you lose weight?

It’s a puzzle. We are drinking more artificially sweetened foods and sodas than ever. We’ve been told that those artificially sweeteners will help us cut calories and keep us slender. Yet, surprisingly, we’re fatter than ever.

Let me put some numbers to that statement. The number of people consuming calorie free sodas in the US alone increased from 70 million to 260 million between 1987 and 2000. During that same time period, the percentage of overweight adults in this country increased from 52% to 66%; the percentage of obese adults increased from 20% to 32%; and the percentage of obese children increased from 10% to 17%. Clearly something isn’t working.

And, it may just be the artificial sweeteners that aren’t working. A study published in 2007 (R. Dingra et al, Circulation, 116: 480-484, 2007 ) showed that people consuming regular (sugar containing) sodas were 48% more likely to become obese over a four-year period than people who primarily drank water. That wasn’t surprising. The surprising finding from this study was that people who consumed diet sodas were just as likely to become obese as those drinking regular sodas.

Now you may be saying: “Wait a minute. I thought I read that consuming diet sodas actually helps people lose weight.” The answer is that in those studies dietitians rigorously controlled the caloric intake from other foods so that the only caloric difference was between the diet sodas and the regular sodas. Under those conditions the results are fairly obvious. Fewer calories from sodas = weight loss. But those aren’t the results that you see in free living populations where you don’t have a dietitian peering over your shoulder. In those populations people consuming diet sodas tend to take in the same number of total calories overall and gain just as much weight as people drinking regular sodas.

 

Do Artificial Sweeteners Prevent Weight Loss?

 

Obviously, people consuming diet sodas which contain artificial sweeteners must compensate by consuming extra calories from other foods. But, why are they consuming those extra calories? Some experts hypothesize that the answer is physiological. The sweet taste of the diet sodas triggers the release of insulin, which drives down blood sugar levels and makes people hungrier. Other experts hypothesize that the answer is psychological. People simply feel virtuous for consuming the diet sodas and feel they can now splurge somewhere else.

do artificial sweeteners help you lose weightAnimal studies have suggested that the cause may actually be physiological. Those studies have shown that there are “sweetness receptors” in the intestine that respond to the sweetness of sugars and trigger an increase in the level of proteins that transport sugars from the intestine into the bloodstream. That makes great sense from an evolutionary point of view. If we’re eating a low carbohydrate diet we really don’t want to waste a lot of energy producing proteins that transport sugars into our bloodstream. However, whenever we eat foods high in carbohydrates we don’t want to waste that carbohydrate. So, our intestine rapidly breaks the carbohydrates down to simple sugars, and our body responds by increasing our ability to transport those simple sugars into the bloodstream.

This can lead to blood sugar swings and increased food cravings. You’ve heard about the blood sugar swings associated with meals high in simple sugars. When sugars enter the bloodstream very rapidly, blood sugar levels increase, which causes insulin to be secreted. The insulin drives down blood sugar levels, leading to hypoglycemia and increased hunger. That’s a highly simplified scenario, but you get the general idea.

Now the interesting thing is that animal studies have suggested that artificial sweeteners are also recognized by the intestinal “sweetness receptors”. So artificial sweeteners also trigger an increase in the intestinal sugar transporters and prime the body so that blood sugar swings are more likely to occur whenever we eat carbohydrates.

While the results from animal studies have been very consistent with this model, the results from human clinical studies have been mixed. Some studies have suggested that artificial sweeteners do increase the likelihood of blood sugar swings, while other studies have reported that artificial sweeteners have no effect on blood glucose and insulin levels.

With this in mind, do artificial sweeteners help you lose weight?  Let’s continue to investigate.

 

Do Artificial Sweeteners Help You Lose Weight?

 

A recent study (M.Y. Pepinoet al, Diabetes Care, 36: 2530-2535, 2013 ) provides a possible explanation for these conflicting results. This study was similar to many of the previous studies in that obese adults were given either sucralose (an artificial sweetener) or water 10 min before being given a fixed amount of glucose, and blood sugar and insulin levels were followed over the next five hours. What made this study unique was that overweight participants were selected who did not normally consume artificially sweetened beverages or foods (Those people are hard to find in the overweight US population).

artificial sweetenersAnd the results were fairly clear-cut. The participants consuming sucralose prior to the glucose load had a 20% greater increase in blood sugar levels, a 20% greater increase in the amount of insulin produced, and significantly lower blood sugar levels three hours after the glucose load than participants consuming water prior to the glucose load. In the words of the authors: “These data suggest that sucralose ingestion is not physiologically inert but affects the glycemic [blood sugar] response to oral glucose load and potentiates glucose stimulated insulin secretion in obese people.” Basically, what they are saying is that sucralose primes their bodies so that they are more likely to experience blood sugar swings when they subsequently consume carbohydrates. [And that can lead to food cravings and weight gain.]

The authors hypothesized that some previous studies had not found an effect of artificial sweeteners on blood sugar and insulin levels because most of the people in those studies were already consuming artificially sweetened beverages on a regular basis and their intestinal sugar transport proteins were already maximally stimulated. Basically, what they are saying is that when someone is regularly consuming artificial sweeteners the damage has already been done (sugar transport is already maximal), and a single dose of an artificial sweetener will not have any significant additional effect.

So, do artificial sweeteners help you lose weight?  I think you know.

 

The Bottom Line

 

It has become clear in recent years that artificially-sweetened diet sodas and diet foods are not effective at preventing weight gain, and may, in fact, contribute to weight gain. There is also increasing evidence that artificially-sweetened diet sodas may be harmful to our health. In fact, an international consortium of obesity experts recently concluded: “The absence of evidence to support the role of artificially sweetened beverages in preventing weight gain and the lack of studies on their long-term effects on health strengthen the position that artificially-sweetened beverages should not be promoted as part of a healthy diet.”

 

However, the reason why diet sodas appear to promote obesity rather than prevent it has remained elusive.

  • A recent study suggests that sucralose (and presumably other artificial sweeteners) triggers a complex serious of metabolic responses that lead to increased appetite and food cravings.
  • However, this is just one small study. Many more studies will be required before we understand why artificial sweeteners promote obesity, rather than prevent it.
  • However, it is clear that artificial sweeteners are not the simple, magical solutions for weight control that food manufacturers and advertisers would have you believe.
    • There are unresolved safety issues with all the artificial sweeteners – but that’s another subject for another day.
    • There is no convincing evidence that artificial sweeteners actually help you lose weight unless you are very carefully controlling the calories from all the other foods you’re eating – and if you’re doing that successfully, you probably don’t need artificial sweeteners in the first place.
    • There is some evidence that artificial sweeteners may actually cause blood sugar swings and make you hungrier, thus making it harder – not easier – to control your weight.
  • The best solution to weight control is always true lifestyle change that includes exercise, healthy foods, and reduced caloric intake and is not based on gimmicks or artificial ingredients.

For more details, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Is Diet Soda Bad For You?

Written by Dr. Steve Chaney on . Posted in Diet Soda and Health

Do Diet Sodas Increase Your Risk Of Stroke?

Author: Dr. Stephen Chaney

diet soda badIs diet soda bad for you?  With over two third of Americans overweight or obese, it is clear that we are in a midst of an obesity epidemic. Multiple studies have shown that over consumption of sugar-sweetened beverages (soft drinks, energy drinks, and “fruit” juices that aren’t made from real fruit) are major drivers of the obesity epidemic. Because of these trends, many experts recommend substituting artificially sweetened beverages for sugar-sweetened beverages in the American diet.

Is that advice sound? Do diet sodas help prevent weight gain? Are they safe? The answers to those questions are not as clear as you might expect.

Do Diet Sodas Prevent Weight Gain?

diet soda make you fatThe answer to that question would seem to be a no-brainer. Substituting beverages with no calories for beverages with calories should lead to less weight gain. However, as I summarized in a previous “Health Tips From the Professor” article Do Diet Sodas Make You Fat, the answer is not clear at all. Some studies suggest that diet sodas help people lose weight. Other studies suggest diet sodas cause just as much weight gain as sugar-sweetened sodas.

With so much confusion in the literature, what should we believe? More importantly, what do the experts say? This January an international consortium of experts reviewed all of the pertinent literature and published a position paper on whether artificially sweetened beverages were of value in responding to the global obesity crisis (Borges et al, PLOS Medicine, DOI: 10.1371/journal.pmed.1002195).

These authors concluded:

  • “In summary, the available evidence…does not consistently demonstrate that artificially-sweetened beverages are effective for weight loss or preventing metabolic abnormalities [pre-diabetes and diabetes]. Evidence on the impact of artificially-sweetened beverages on child health is even more limited and inconclusive than in adults.”
  • “The absence of evidence to support the role of artificially sweetened beverages in preventing weight gain and the lack of studies on their long-term effects on health strengthen the position that artificially-sweetened beverages should not be promoted as part of a healthy diet.”

Is Diet Soda Bad For You?

diet soda strokeAs if the lack of proven efficacy weren’t bad enough, other studies suggest that diet sodas may also be bad for your health. In previous issues of “Health Tips From the Professor,” I have discussed other studies showing that diet sodas are just as likely as regular sodas to increase risk of diabetes Artificial Sweeteners and Diabetes and heart disease Soft Drinks and Heart Disease.

Even worse, a study published earlier this month (Pase et al, Stroke, DOI: 10.1161/STROKE.AHA.116.016027 ) concluded that diet sodas may significantly increase the risk of stroke and Alzheimer’s disease.

This study looked at 2888 participants of the Framingham Heart Study. The participants evaluated for risk of stroke had a mean age of 62 on enrollment. Those evaluated for risk of dementia had a mean age of 69 on enrollment. All subjects were followed for 10 years. Three food frequency questionnaires were administered during that 10-year period to evaluate consumption of diet and sugar-sweetened sodas. The results of the study were:

  • People consuming at least one diet soda per day over a 10-year period were 3X more likely to have a stroke or develop dementia (primarily Alzheimer’s disease) than people consuming no diet sodas.
  • No increased risk of stroke or dementia was seen for people consuming sugar-sweetened beverages. However, that does not mean that sugar-sweetened beverages are good for you. Previous studies have shown they increase the risk of obesity and diabetes.
  • When the data were corrected for hypertension, cardiovascular disease, and obesity (waist to hip ratio), diet sodas still increased the risk of having a stroke by 2.6-fold.
  • This is not the only study to show a link between diet sodas and stroke. Two other studies have come to the same conclusion, and in both of those studies the increased risk was also seen only with diet soda consumption, not with sugar-sweetened soda consumption.

The author of the study concluded by saying: “As the consumption of artificially sweetened soft drinks is increasing in our community, along with the prevalence of stroke and dementia, future research is needed to replicate our findings and to investigate the mechanisms underlying the reported association.”

I agree. Current evidence does not definitively prove that diet sodas cause stroke and Alzheimer’s, but these are life-changing adverse health outcomes. Further research to test this association is desperately needed to know whether or not diet soda is bad for you.

Are Diet Sodas Safe and Effective?

diet soda dangerousAs you might expect these studies have caused quite a bit of controversy. Some experts have embraced these studies and have concluded that health professionals should stop recommending diet sodas as a safe and effective alternative to sugar-sweetened sodas.
Others have been unwilling to change their recommendation of diet sodas for people who are obese and/or diabetic. Their rationale is 3-fold:

  • These studies merely show that diet soda consumption is associated with weight gain, diabetes, heart disease, stroke and Alzheimer’s. Association does not prove causation, so their viewpoint is that there is no conclusive proof that diet sodas cause weight gain and health risks.
  • The obesity epidemic is a major health crisis, and consumption of sugar-sweetened beverages plays an important role in weight gain.
  • They are convinced that most people are so addicted to the sweet taste of sugar that they would be unwilling to switch to calorie free options like water or herbal teas.

In short, they are desperately clinging to the hope that substituting diet sodas for sugar-sweetened sodas will put a dent in the obesity crises because they don’t believe there are any other viable options.

What Do These Studies Mean For You?

I side with those experts who have looked at the data from the opposite perspective and concluded there is no convincing evidence that diet sodas are either safe or effective.

If the conversation were just centered around weight gain, diabetes, and heart disease, this could be considered an academic discussion. One could argue that diet sodas might have some benefit, and, at the worst, would have the same health risks as the regular sodas they replaced.

However, the possibility that diet sodas may increase the risk of stroke and dementia is a game-changer in my mind. That’s because consumption of sugar-sweetened sodas does not appear to increase the risk of either stroke or dementia. If true, that means that substitution of diet sodas for sugar-sweetened sodas is not a neutral substitution. It could cause serious harm.

With no good evidence that diet sodas help people control weight and the possibility that they may have serious health risks, it is difficult to see how anyone in good conscience can continue to recommend diet sodas in place of regular sodas.

My recommendation is to substitute water and other unsweetened beverages for the sugar sweetened beverages you are currently consuming. If you crave the fizz of sodas, drink carbonated water. If you need more taste, try herbal teas or infuse water with slices of lemon, lime, or your favorite fruit. If you buy commercial brands of flavored water, check the labels carefully. They may contain sugars or artificial sweeteners. Those you want to avoid.

So, is diet soda bad for you?  Well, it’s not good for you.

The Bottom Line

  • This January an international consortium of experts reviewed all of the pertinent literature and concluded: “The available evidence…does not consistently demonstrate that artificially-sweetened beverages are effective for weight loss or preventing metabolic abnormalities. The absence of evidence to support the role of artificially sweetened beverages in preventing weight gain and the lack of studies on other long-term effects on health strengthen the position that artificially-sweetened beverages should not be promoted as part of a healthy diet.”
  • This April a study was published reporting that people consuming at least one diet soda per day over a 10-year period were 3X more likely to have a stroke or develop dementia (primarily Alzheimer’s disease) than people consuming no diet sodas. Two other studies on the effect of diet sodas on the risk of stroke have come to similar conclusions.
  • We cannot yet say definitively that diet sodas cause stroke and dementia. Further research is clearly needed to test these associations. However, at this point it is safe to say there is no convincing evidence that diet sodas are either safe or effective.
  • With no good evidence that diet sodas help people control weight and the possibility that they may have serious health risks, it is difficult to see how anyone in good conscience can continue to recommend diet sodas as a substitute for sugar-sweetened sodas.
  • My recommendation is to substitute water and other unsweetened beverages for the sugar sweetened beverages you are currently consuming. If you crave the fizz of sodas, drink carbonated water. If you need more taste, try herbal teas or infuse water with slices of lemon, lime, or your favorite fruit. If you buy commercial brands of flavored water, check the labels carefully. They may contain sugars or artificial sweeteners. Those you want to avoid.
  • For a more nuanced discussion of this issue, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

For more details read the article above.

 

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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