Sweeteners may not be a sweet deal as the World Health Organization (WHO) has advised against relying on sugar-free sweeteners for weight control, citing studies that show their long-term use increases the risk of weight gain and obesity.

Sugar-free sweeteners can help lose weight or prevent further weight gain in the short term.

"The WHO suggests that non-sugar sweeteners not be used as a means of achieving weight control or reducing the risk of non-communicable diseases," the new guideline reads.

Apart from that, the WHO also recommends reducing sugar consumption.

WHO experts have reviewed numerous studies on the use of sugar-free sweeteners, showing long-term use was associated with increased risk of type 2 diabetes, cardiovascular diseases (CVDs) and mortality in prospective cohort studies conducted in adults. Fewer studies have been done on children.

Overall, there is little evidence that the consumption of sweet drinks with sugar-free sweeteners contributes to fat reduction.

However, two studies showed that drinks with sweeteners instead of sugar reduce tooth decay. The WHO states billions of people are affected by being overweight or obese.

In 2016, 1.9 billion adults worldwide were overweight and over 600 million of them were severely overweight.

In 2020, 38 million children under the age of 5 were overweight.

A high body mass index (BMI), which is used to estimate a person's body fat percentage, lead to 4 million deaths worldwide in 2017. BMI is determined by height and weight.

The WHO bases all figures on the latest available estimates. Sugar-free sweeteners include all synthetic and natural sweeteners, including products made from the plant stevia.