I wish it astonished me that people are still publishing studies about non-nutritive sweeteners’ purported links to weight gain despite the lack of any such finding in formal trials or in the post-market surveillance of these additives’ longstanding and widespread use.

I say “I wish” because I wholly understand that in part, study topics and designs are influenced by public interest, and no doubt there has always been interest in the demonization of non-nutritive sweeteners, as well as in the interest of finding a simple solution to the complex issue of societal weight gain. This interest probably stems from the common naturalistic fallacy that posits that “artificial” equals bad and “natural” equals good, a fallacy spurred on by the likes of America’s new Department of Health and Human Services Secretary Robert F. Kennedy, Jr, and the MAHA (Make America Healthy Again) movement.

How badly do people want to believe non-nutritive sweeteners are a danger? Consider this recent crossover study where researchers examined the impact of consuming a beverage consisting of sucralose and water vs one consisting of sucrose and water on functional MRI (fMRI)-measured hypothalamic blood flow, as well as plasma glucose, insulin and glucagon-like peptide 1 (GLP-1). The researchers were measuring these things as surrogates for hunger. I will come back to the results in a moment, but skipping straight to the first line of their conclusion, “Our findings indicate that the non-caloric sweetener sucralose can affect key mechanisms in the hypothalamus responsible for appetite regulation,” would certainly lead one to think that the sucralose arm was uniquely, for lack of a better word, hungrifying. And indeed, the researchers found those surrogate hunger markers did seem to differ between the sucralose and sucrose crossovers whereby with sucralose the surrogate markers were skewed toward levels supportive, based on their belief of the markers’ predictive utility, of heightening hunger.

As to this very small crossover study’s extensive coverage, it near uniformly spoke to sucralose increasing hunger. From social media posts on X (many from healthcare professionals who in turn serve as nutrition, obesity, or science influencers), to science publications mainstream media outlets, nearly all wrote with at times emphatic concern regarding sucralose consumption and the broad genesis of hunger and, of course, weight.

When it comes to non-nutritive sweeteners and weight, I’m not aware of any randomized controlled trial (RCT) that has shown meaningful weight gain consequent to their consumption (something you might expect if they increase hunger). And meta-analyses of RCTs and other sustained interventions also conclude that the use of low- and no-calorie sweeteners in weight management, despite the fMRI findings reported above, is in fact beneficial to weight loss.

But back to that fMRI study that has influencers, doctors, professors, and the media warning about sucralose, hunger, and weight gain, there are two rather important shortcomings. Firstly, weight and dietary intake were not measured. But, happily, researchers, rather than simply collecting fMRI measurements and blood biomarker values, also collected something else perhaps important: subjective reports of hunger.

Certainly, based off the coverage and assuming you want to ignore the wealth of evidence showing if anything the use of low- and no-calorie sweeteners are helpful to weight loss efforts, you’d think those subjective reports would be dramatic. That consuming sucralose and water would see subjects reporting heightened hunger. You’d be wrong though, which brings me to the second important shortcoming: The study found that subjective hunger did not differ between sucralose-sweetened water consumption and consumption of just plain old water. Unless you believe consuming water heightens hunger significantly, this study is not a cause for concern.

I, too, would love there to be a dietary boogeyman to blame for our various diet related ills and concerns, especially obesity, but low- and no-calorie sweeteners almost certainly aren’t it.