Sweeteners: fatten or let you lose weight?

Lean substitutes of sugar have been considered as controversial in diet for many years. Their influence on health and body mass and composition raises a lot of emotions. In this article I would like to cope with the latter aspect, as it is very surprising. After all, substances like aspartame or sucralose almost lack calories (opposite to saccharose). So, is it even possible that these compounds make it hard to lose weight and complicate it even more by fostering gaining weight?

You should definitely read:

Stevia – a natural sweetener as an alternative for aspartame

Lean substitutes of sugar – what are they?

Lean substitutes of sugar, also called sweeteners, are the sweetening substances “created” to replace sugar and this way lower the calorific content of food. Among others, there are the following sweeteners:

  • aspartame (the consumption of which is connected with majority of controversies and which is also best researched artificial sweetening substance from the influence on health point of view),

  • sucralose (commonly perceived as “a safe substitute of aspartame”, in fact, it is no better researched than other sweeteners, and its use also causes controversies, which derives from the fact that it releases some amount of chlorofructose and chloroglucose),

  • acesulfame potassium (one could have more reservations to this compound than to aspartame, however, FDA and EFSA considered this sweetener as safe after detailed studies),

  • saccharinates (studies on rats proved that these compounds are definitely harmful, however tests on humans did not confirm the negative influence on the body),

  • cyclamates (under the influence of intestinal bacteria cyclohexalamine maybe formed – harmful substance, which is why the upper safety limit of intake is set on quite low level comparing to e.g. aspartame).

In the group of sweeteners there are also polyols, i.e. polyhydroxy alcohols, which also have sweet taste and lower calorific content, as well as different metabolism than saccharides, such as saccharose, glucose or fructose. The properties mentioned above cause that these compounds are considered as more “dietetic” than table sugar. In the EU in food industry the following polyols are used:

  • sorbitol,

  • mannitol,

  • isomalt,

  • sorbitol syrup,

  • maltitol syrup,

  • maltitol,

  • lactitol,

  • xylitol,

  • erythritol.

There are some controversies also around polyols, but they mainly concern their influence on the digestive tract. For some people these compounds cause diarrhea, bloats and sometimes stomachache.

In the group of sweeteners there are also steviosides – compounds of plant origin (their source is stevia). This substance is considered safe, but not all the consumers accept the taste of products sweetened with it. Another natural sweetening substance is tagatose, which has some pro-health properties.

Doubts about sweeteners

There are many controversies about the way the consumption of sweeteners influences body mass and composition. On the one hand, it seems obvious, that replacing table sugar and glucose-fructose syrup with low-calorific substances (or even those lacking calories) is a milestone towards decreasing the risk of development of overweight and obesity. On the other hand, one may have doubts if the body can be “tricked” this way. After all, sweet taste in nature usually occurs together with carbohydrates. This matter is additionally complicated by the results of studies, of which the outcome is ambiguous. In some attempts there is negative, in other – positive influence of the consumption of sweetening substances on body mass and composition. There are also some trials, in which these compounds seem totally neutral.

Sweeteners vs body mass and composition – an interesting hypothesis

The opponents of using sweeteners often invoke an interesting hypothesis, according to which the impression of sweet taste causes the cascade of neurohormonal reactions similar to those, which take place when we eat table sugar. In other words, when we drink a glass of sugar-free cola sweetened with aspartame, sucralose or acesulfame potassium, there is the release of insulin – the hormone, which is supposed to lower glucose in blood by allocating it to the tissues and organs that need it. In case when there is glucose in blood, insulin would decrease its level to the “physiological level”, whereas, in a situation, when it occurs that there is no sugar in blood – insulin would lead to hypoglycemia. Body, in order to balance glycemia, will start the compensation mechanisms by stimulating hunger and forcing us to grab some “fast source of energy”, e.g. a chocolate bar, biscuit, bar of chocolate, etc. As a result, we eat more and cause the increase of body mass.

Verifying the critical hypothesis

The problem is that there aren't any convincing studies on humans, which would confirm those assumptions. Indeed, in few of the studies done on animals, many intriguing dependencies between consuming some synthetic sweeteners and the hormonal response and the regulation of hunger, were revealed, but there are indications to think that these mechanisms are not activated in human body.

This topic is still controversial, however, there is no proof, which would confirm the hypothesis, according to which sweeteners cause the increase of insulin production and then lead to hypoglycemia. This issue has been verified in scientific experiments and, in case of people, despite attempts, it has not been confirmed. However, it does not end the speculations. The opponents of sweeteners cite the studies, which proved that there is a correlation between the consumption of products sweetened with such substances, like aspartame or sucralose, and the problem of excessive body mass. But, first of all: correlation does not mean the cause and effect connection (here, e.g. increased intake of sweeteners may be caused by the will of coping with overweight and obesity), second of all: it is not confirmed in the intervention studies.

The Salomon's point

As you can see, the issue of the influence of the consumption of sweeteners on the body mass and composition is complex and raises a lot of controversies. The confusion could be also bigger because there were no extended studies in the available literature, which would take under consideration the results of various studies and which would explain the differences in the outcome. Only two weeks ago a very interesting work was published, which treats the mentioned issues across the matter. Its authors came to some interesting conclusions and assumed that using low-calorific sweeteners instead of table sugar may be helpful in decreasing the supply of energy and lowering excessive body weight (the researchers also underlined the fact that the proof in a form of experiments done on people are lacking, and that the situation may be opposite). According to the authors, the assumptions, which state that the consumption of sweeteners may increase the risk of overeating and lead to the increase of body mass derive from the tests done on animals.

The scientists also suggested to reflect on the fact that the differences in the tests' results could be caused by the wrong methodology of intervention experiments done on people, which, in most cases, leads to opposite results than tests done on animals... Another interesting conclusion concerned a curious trend, according to which many studies verifying the influence of the consumption of sweeteners on the body mass and composition ends with the summary that “there's the need of further studies”. Despite that fact, there does not exist any other new hypothesis, which would require testing, nor any limitations of the current research study. The authors cited one of the works, which was following:

“lean replacements of sugar may be potentially helpful in managing body mass, but if they are used this way, is not a certainty”.

In fact, I suppose, it's much better not to wonder if sweeteners are “good” or “bad”, but rather think how to use the fact that they are sweet and low-calorific. You can read more of the conclusions from the results of studies in the work linked below:

http://www.nature.com/ijo/journal/vaop/ncurrent/full/ijo2015177a.html