This is a very hot topic at present. With more and more evidence that sugar is bad for us, I am noticing many people are knowingly or unknowingly leaning towards artificial sweeteners.

I often get asked by my patients as well if swapping sugars to artificial sweeteners would be an ideal choice?

It is still a very controversial topic but lots of research is being done. I thought of putting together a blog so people can make an informed choice.

As sugar is known to have a negative impact on overall metabolic health, one of the ways to reduce the energy density of foods and beverages is to introduce artificial sweeteners while still maintaining taste.

However, are these substitutes safe?

So let’s have a look.

Main ways the artificial sweeteners work (1)

  • Artificial sweeteners may taste sweet but they numb the taste receptors to sweet taste. This then leads to craving for higher levels of sugar tasting food for the same satisfaction.
  • There are lots of sweet taste receptors in various organs of our body, for example in the brain, gut and the pancreas. These receptors have an important role in regulating the sugar in our blood. Artificial sweeteners can have a negative effect by increasing the signals for these receptors, which then result in increased blood glucose and insulin levels – by taste alone. This increase in insulin levels can then lead to weight gain and insulin resistance, which clearly defeats the whole purpose of using the artificial sweetener in the first place!
  • In a small study it was seen that by simply reducing the food item to a lower calorie by use of artificial sweeteners may lead to ‘rebound eating’. This was seen as participants felt less satiated. In fact the levels of ghrelin, the appetite stimulating hormone, were seen to be lower because participants who consumed the real sugar food believed their food was ‘indulgent’ rather than ‘sensible’.
  • Artificial sweeteners could change the gut microbiota just within a week, which can in turn can lead to glucose intolerance, as a result of disruption of balance of the healthy gut bacteria. This has been again shown to result in weight gain as it increases insulin resistance in the long run.

In a recent large prospective study published in the BMJ, artificial sweeteners (especially aspartame, acesulfame potassium, and sucralose) have been associated with an increased risk of cardiovascular, cerebrovascular and coronary heart disease (2). Further studies would be needed to confirm causation however it does make one think if these chemicals which are added to most of our ultra-processed food (along with many others) are the best way forward. I often see children walking into consultations with a bottle of fizzy drink or juices labelled ‘no sugar added’. It makes me question our health policies and what the government is doing to support the future generation’s health.

In another small randomised controlled trial, it was seen that low calorie sweeteners which included sucrose and saccharin significantly increased the body weight when compared to aspartame, rebA, and sucralose. So different types of low calories sweeteners can have different effects and not all can be swept under the same heading, when it comes to effect on health (3)

In short term studies it has been seen that the low calorie sweeteners can help with weight loss however they do not provide long-term outcomes of health of these participants (4). I would want to know how these individuals did in terms of maintaining weight loss or even how was their general health in the long term. Artificial sweeteners maybe sweet or even sweeter than the natural sugars but their calorie content and metabolism routes with in the body would be totally different due to the chemical compounds.

Looking into further articles, several meta-analyses and randomised controlled trials looked at effects of artificial sweeteners on the human body and obesity. The results were not significant enough to promote the use of these chemicals when considering gut health, improving insulin resistance or weight (5).

There is some evidence that ‘stevia’ maybe a healthier sugar alternative as it is natural however more research is needed to confirm this.

So my take would be use artificial sweeteners as a transition substitute while you are stepping into new routine of improving health, as opposed to as a long term sugar substitute. This is what I share with my patients too and encourage them to move towards ‘whole food’ as much as possible.


  1. Physiological mechanisms by which non-nutritive sweeteners may impact body weight and metabolism –
  2. Artificial sweeteners and risk of cardiovascular diseases: results from the prospective NutriNet-Santé cohort –
  3. A randomized controlled trial contrasting the effects of 4 low-calorie sweeteners and sucrose on body weight in adults with overweight or obesity
  4. Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies
  5. The Impact of Artificial Sweeteners on Body Weight Control and Glucose Homeostasis