In recent decades, with the growing obesity pandemic, added sugars have been the focus of attention of major health institutions such as the World Health Organization (WHO), which recommends that these sugars account for no more than 5–10% of total caloric intake.

In this context, we are experiencing a transition in which sweeteners, flavorings, and other additives have become a regular part of our diet. Today, they are found in most products, including sports nutrition.

However, many athletes do not consider a key question:

How do sweeteners and additives affect health and sports performance?

The use of sweeteners and additives in sports nutrition

The sports supplement market is flooded with protein shakes, gels, bars, and other products with “cookie,” “red berry,” “cola,” and countless other flavors made possible by processed chemical products.

Although reducing sugar content is not usually the main reason for adding these flavorings (in sports, the current trend is rather the opposite: consuming more and more carbohydrates), these compounds make it possible to increase the palatability of products or even change their color to improve appearance.

However, it is striking that athletes—people who in many cases take care of even the smallest detail of their diet and training—do not consider the possible consequences of regularly ingesting these sweeteners or flavorings.

Consequences of sweeteners and flavorings for health

Interestingly, despite having no calories, the intake of sweeteners and other additives has been associated not only with a higher risk of obesity, but also with poorer metabolic health.

For example, one study analyzed the consumption of products with sweeteners such as aspartame or saccharin in more than one hundred thousand people over 9 years [1]. The results showed that high consumption of these products was associated with a 69% higher risk of developing type II diabetes, regardless of other factors such as age, weight, or level of physical activity.

Due to these findings, since 2023 the WHO has recommended not consuming sweeteners, not even with the goal of losing weight, as they may be ineffective in the long term and even harmful to health.

Effects on the gut microbiota

There is increasing evidence that one of the main mechanisms by which sweeteners, flavorings, and other additives affect health is their impact on the gut microbiota.

The microbiota plays a fundamental role in health, modulating, among other functions, the inflammatory state of the body. Dysbiosis (alteration of the microbiota) has been associated with the development of metabolic diseases and even cancer.

In addition, the microbiota plays a key role in sports performance, helping to optimally metabolize nutrients and promoting adaptations to training.

In this regard, it has been observed that high consumption of ultra-processed foods containing sweeteners or flavorings can alter the microbiota.

For example:

• Consumption of saccharin can modify its composition and promote glucose intolerance [2]
• Some emulsifiers, such as carboxymethylcellulose, can reduce bacterial diversity within a few days and increase inflammation [3]

Conclusions

Although there is a lack of specific evidence in athletes and most studies are observational, in the general population high consumption of ultra-processed products rich in sweeteners, flavorings, and other additives has been associated with alterations in the microbiota and metabolic health.

Given the relevance of the microbiota for both health and sports performance, minimizing the intake of these products may be an interesting strategy for athletes.

FAQs

Do sweeteners affect athletes’ health?

Occasional consumption does not seem problematic, but high and regular intake has been associated with alterations in the microbiota and metabolic health.

Can sweeteners affect sports performance?

Indirectly, yes, since the gut microbiota influences nutrient absorption, inflammation, and recovery.

What does the WHO say about sweeteners?

Since 2023, the WHO has recommended avoiding their use as a weight-loss strategy due to possible long-term negative effects.

Is it better to avoid flavored products in sports nutrition?

It is not necessary to avoid them completely, but prioritizing products with simple formulations may be a more favorable strategy.

Author:

Pedro Valenzuela

References

1.            Debras C, Deschasaux-Tanguy M, Chazelas E, Sellem L, Druesne-Pecollo N, Essedik Y. Artificial Sweeteners and Risk of Type 2 Diabetes in the Prospective NutriNet-Sante Cohort. Diabetes Care 2023; 46.

2.            Suez J, Korem T, Zeevi D et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature 2014; 514: 181–186.

3.            Chassaing B, Compher C, Bonhomme B et al. Randomized Controlled-Feeding Study of Dietary Emulsi fi er. Gastroenterology 2022; 162: 743–756.