Many foods can be categorized as “healthy” (fruits, vegetables) or “unhealthy” (pizza and chips). Light drinks are an exception, because they are in a certain gray area: no one really knows whether Coke with sugar or Coke with sweeteners is better or worse. And so some despise diet drinks as artificial chemical bombs, while others are downright addicted to the calorie- and sugar-free indulgence.

What are light drinks?

There is a sugar-free light version of many soft drinks, which tastes (almost) exactly like the sugary drink. However, the sweetness is not produced by sugar, but by sweeteners such as aspartame. These sweeteners have, as the name suggests, a high sweetening power, but your body has no enzymes to break them down, so you can’t use the calories. Aspartame and Co. are however again and again in the suspicion health-harmful to be.

Why soft drinks without sugar are so popular?

Jane Ogden, Professor of Health Psychology at the University of Surrey in Guildford (England), explains why: “Many people are permanently on a diet. The word diet means to them being slim and in control of themselves.”The majority strive to keep body fat levels low. The negative sugar headlines in recent years have done their bit to make sugar-free soft drinks very popular. Many choose the sugar-free option because they want to consume less sugar and can still appease their craving for sweets with the light drinks.

Do light drinks make you fat?

The advertising messages of diet drinks convey enjoyment without remorse, without calories and without excess weight. But one in the “American Journal of Clinical Nutrition” published study examined the effect of soft drinks on body weight and found: Participants who consumed one liter of a sugary soft drink each day gained about 10 kilograms in 6 months. Test subjects who consumed a diet drink instead gained only 1.5 kilograms in comparison.

Sweeteners therefore have a much more positive effect on weight than sugar and can be quite helpful in losing weight. Nevertheless, light drinks are not weight-neutral, even if they contain no calories.

What do light drinks do?

The consumption of artificial substances triggers a series of biochemical processes in your body and can thus make it more susceptible to obesity. “The subjects with the light drinks in the study gained weight not because they had consumed more calories, but because their insulin levels had risen,” explains Robert Funny, Professor of endocrinology at the U.S-University of California in Oakland.  “The more insulin is in their blood, the more sugar is stored in the cells as fat.” Insulin transports sugar into the body’s cells, where it is either converted into energy or stored in the form of fat.

So sugar-free drinks make your insulin levels rise, even though they don’t contain sugar. This was also shown by the results of a study published in the US journal “Diabetes Care” published study. Group 1 consumed a non-alcoholic and non-caloric drink, group 2 nothing at all. The glucose and insulin levels of all participants were then measured. The results showed that the group with the drinks had 20 percent more insulin in their blood than the control group.

Why do light drinks affect insulin levels?

When the sweet stimulus hits our tongue, special receptors are activated that signal the brain that sugar has been ingested. “The brain then tells the pancreas to release insulin to transport the glucose into the cells,” explains Professor Robert Lustig. This is all happening in your body, even though no sugar molecule has passed your lips.

Sweeteners confuse the taste buds

They’re called aspartame, saccharin and sorbitol and have no calories, but no nutrients either. However, the sweetening power of artificial sugar alternatives from the lab is many times greater than that of sugar. Because of their high sweetening power, they are only used in small quantities. Especially in people who give up sugar completely, sweeteners have a very aggressive effect on taste receptors. “There can be consequences if you drink artificially sweetened drinks without eating real sugar,” says Lustig. “The point of a sugar-free lifestyle, after all, is actually to become more sensitive to sweet foods. But if you regularly consume light drinks with sweeteners instead, the exact opposite happens.”

The taste buds are so overstressed by sweeteners that other naturally sweet-tasting foods are no longer perceived as sweet. This makes the craving for the light drinks even greater.

How unhealthy are light drinks?

There are numerous studies on the subject of sweeteners – but science is still not in agreement on whether the chemical sugar substitute is healthy or unhealthy. Fact: Foods that are not safe are not approved in Germany. Nevertheless, there is a lack of long-term studies. The Federal Institute for Risk Assessment (BfR) and the European Food Safety Authority estimate sweeteners like aspartame to be safe when consumed in moderation. However, studies repeatedly point to a link with cancer, diabetes and obesity. The most common theses:

  1. Sweeteners are said to harm the intestinal flora: They do this by acting on microorganisms. These are involved in digestion and break down carbohydrates. It is believed that sweeteners promote the spread of microorganisms. This would accelerate the absorption of sugar into the body. For scientists, the connection sounds quite plausible. However, the results obtained in mice have not yet been confirmed in humans.
  2. Sweeteners are suspected of causing cancer: The statement cannot be supported or refuted by recent studies. A study in the 1960s had shown a link between saccharin and bladder cancer in rats. However, the rats were given an extremely high amount at that time, which could never be consumed by a human being in this way (20 kilograms of sugar or. 4000 sweetener tablets). Aspartame continues to be suspected of causing cancer. This was also tested on rats. Background: Degradation products of aspartame are the carcinogenic substances methanol and formaldehyde. However, it is still disputed whether the quantities under consideration are sufficient to pose a risk.
  3. Sweeteners could be the cause of cravings: Sweeteners act on the brain and trigger cravings there because the brain waits for sugar through the sweet stimulus. But if it fails to do so, the brain is confused and cannot interpret the information. If this happens frequently, it interprets the process as a nutrient crisis and demands more food. The correlation is now considered fairly certain in research.

Conclusion: Water is still the best alternative

The subject of sweeteners is a real one. The study situation is controversial and opaque. But the fact is that sweeteners such as aspartame have been deemed safe by several authorities and are less fattening than sugary drinks, because sweeteners are calorie-free. But they are not a miracle cure that will help you lose weight. If you want to lose weight and eat healthy, it is best to avoid sugar and sweeteners. Water is still the best alternative to quench your thirst. But every once in a while you can treat yourself to a cola – with sugar or sweetener.