Dr. Ludwig hypothesized that people who carry a lot of belly fat could benefit most from replacing sugary drinks with diet drinks or water, because in response to sugar they secrete more insulin, a hormone that promotes fat storage. “Someone who is slim may not be that sensitive to sugar,” he said.
The debate about the effects of artificial sweeteners on health and body weight has raged for decades. Some of the earliest concerns came from animal testing in the 1970s that suggested that artificial sweeteners could cause cancer. Later human studies denied these claims, and the American Cancer Society, which reviewed the evidence in 2016, among others, claims that there is no clear evidence of a link between low-calorie sweeteners and cancer in humans.
The influence of artificial sweeteners on body weight has also been controversial. Over the years, some observational studies have found that people who consume a lot of diet drink are at greater risk of obesity, suggesting that artificial sweeteners may promote weight gain rather than prevent it. However, observational studies can only show correlations, not cause and effect. The reverse causality can be a factor as people who are more likely to use artificial sweeteners may gain weight for a variety of reasons, such as: B. due to other nutritional factors and lack of exercise.
Randomized clinical studies, which are more reliable, have generally shown that dietary sweeteners help prevent weight gain. A clinical study published in the New England Journal of Medicine found that children who consumed sugary beverages had less weight gain and fat accumulation after 18 months than children who continued to drink sugary beverages.
Another clinical study conducted by researchers from the University of North Carolina at Chapel Hill found that overweight and obese adults who were instructed to avoid sugary drinks for water or low-calorie sweetened drinks for six months averaged 2 to 2 .5 percent lost their body weight. However, the group that switched to water showed significant improvements in their blood sugar levels, a risk factor for diabetes, while the group that used low-calorie sweeteners did not.
The latest study by Dr. Ludwig and his colleagues are among the strictest on this subject. The results support the recommendations of health groups such as the American Heart Association, who published a scientific note in 2018 that the use of low-calorie sweetened beverages could be an effective strategy for weight loss, especially for people who commonly consume sugary drinks, which are the largest source of added sugar in the American diet.
However, the Heart Group also warned that there was "a lack of evidence of the possible adverse effects" of the sweeteners. Despite decades of widespread use, it is still unclear whether heavy consumption over many years can have unintended harmful effects. And they are not all the same. Last year, Purdue University scientists published the results of a clinical study comparing the effects of sugar and four different low-calorie sweeteners on weight gain in overweight and obese adults.