In case you are unaware, there is a constant raging debate regarding the use of sweeteners (sugar substitutes) and their influence on weight gain/ loss and their link to issues such as obesity and diabetes.
On one side the use of sweeteners is suggested to be a calorie-free alternative to sugar (which the media has now latched upon to following the “revelations” that fat is not the terrible nutritional devil many thought it was).
In this article we will aim to dispel some of these myths and give clarity to an area which is downright confusing!
Sugar vs Sweetener
As a society, we love sugar! Consumption of added sugars in the US has grown by 20% in the past few decades (1.)
It’s not just in our fizzy drinks, and our sweets and our cakes; but it is in all of the meals which pack the supermarket shelfs, in bottle sauces and in breakfast cereals. Even snacking on fruit comes into question due to high contents of fruit sugar!
…So much so that the area of health and nutrition science have for decades focused on alternatives to its use in our nutrition plans.
High amounts of table sugar in our diets have been found to cause weight gain (2). Such high sugar diets have also been found to have negative effects on our bodies’ tolerance to glucose (3).
Diets high in fructose (sugars found in fruit) have also been shown to increase insulin sensitivity, fatty accumulation around your organs and cellular fat tissue collection (4-5).
Why Insulin Sensitivity Can Make You Gain Weight…
Well… let’s just say – when you eat carbohydrates the digestive system breaks them down chemically. This leaves a greater amount of saccharides (simple sugars such as glucose and fructose) and disaccharides (large sugar molecules such as sucrose and lactose) in your blood.
The body reacts to higher sugar amounts in your blood by asking the pancreas to release a specific hormone, insulin, which prompts our organs (e.g. the liver and muscle cells) to pull in the sugars to use for energy (needed for all that training!)
Just as our bodies can become accustomed to a certain amount of coffee or alcohol, the same can be said for consuming carbohydrates.
If there is a regular supply of sugar into our bloodstream then the resulting release of insulin has less and less of an effect on our bodies to pull the sugars into our tissues for fuel. We then need to release more insulin for the same effect, and if left untracked, this can lead to us being unable to use our glycogen (stored sugar) stores appropriately and we gain weight – to put it simply…
Hidden Sugar Substitutes
Let’s be honest – we live in world where many of the population want to satisfy their sweet tooth, in which a lot of time and money has been spent by companies in developing artificial sweeteners which are calorie free. (those lovely words!)
Unfortunately, it has been theorised that sweeteners ALSO have a detrimental effect on insulin sensitivity!
It is thought that approximately 15% of the US population consume these types of “non-nutritive” sweeteners regularly (6). The most commonly known “non-nutritive” sweeteners are:
✓ Acesulfame K (acesulfame potassium)*
*These are all approved by the US Food & Drug Administration for use in foods and beverages for public purchase and consumption.
There are also sugar alcohols which are termed “nutritive” sweeteners (such as glycerol) which are directly created from sugar but do not have the same high calorie energy values than sugars…
“I Thought Sweeteners Would Help Weight Loss?”
Studies suggest the use of some of the above low calorie sugar alternatives can actually ASSIST weight management! For example:
Aspartame has been shown to:
✓ Reduce food intake
✓ Assist control of body weight (7)
However, most review recommendations make conclusions which suggest that there are no official recommendations for their use for this purpose (8).
There are even studies which suggest the contrary and that aspartame may stimulate appetite leading to weight gain (9-10)… the science of it is literally a minefield!
What about our trusty Stevia?
Whilst the use of Stevia is not FDA approved in the US, it is seen stocked on the shelves of most supermarkets in the UK. This sugar substitute is slightly different from other artificial sweeteners in that it is a natural extract from the leaves of the Stevia rebaudiana Bertoni plant.
SO…Will Sweeteners Promote Weight Gain Or Not?
Artificial sweeteners can trigger a range of reactions causing insulin to be released, even when a sugar is not consumed. As such this insulin release and subsequent glucose storage leads us to weight gain and potentially on the brink of diseases such as diabetes.
This may be also supported in argument by studies which identify that those who drink more diet soda gain more weight than those who do not. Although this is also debated as it may be more due to alterations in your psychological behaviour and the activation of sweet taste cravings by such beverages (11).
Interestingly, despite the evidence already demonstrated, in healthy human subjects such changes in blood insulin levels are not clearly apparent.
Let’s just take a closer look at two of the most popular sweeteners, mainly labelled as…
“Good” VS “Evil” |
Stevia VS Aspartame
Stevia VS Aspartame
Recent studies show that consumption of stevia and aspartame both show reduced glucose and insulin blood levels compared to sugar (8). This study measured effect of pre-meal preloading with stevia, aspartame and sucrose to assess whether each substance consumed prior to meals would alter the subsequent food intake during the day, appetite satiation or the level of insulin/ glucose released.
Their results indicate that consumption of stevia and aspartame maintains the degree of “fullness” after eating (compared to a meal plan including carbohydrate) with a reduced effect on insulin and glucose levels!
They also showed that reduced calorie intake by use of sweeteners in one meal, had no negative effect on the degree of calories consumed later in the day, supporting the conclusions of previous studies (12-13).
Additionally, they found that Stevia had a greater benefit than aspartame and that both substances caused the food to taste better (sweeter) than just sugar. Sweeteners are generally 300-800 times sweeter than sucrose (14).
Take home message
Answering whether artificial sweeteners cause detrimental effects on insulin sensitivity and weight gain is difficult for a couple of reasons.
1) A lot of the scientific studies contradict each other
2) There are lots of different studies examining different things in different types of sweeteners
3) What happens in laboratory and animal experiments doesn’t not entirely seem to correlate with what actually happens when humans ingest these substances.
However, it seems that generally most people will not see a significant insulin release by consuming artificially sweetened products. However, if you are obese or have type II diabetes you may be more susceptible to weight gain from these products.
Use of sweeteners in moderation should be fine, and is no excuse for reverting to full sugar products!