A recent study published in the journal Appetite suggests that low-calorie sweeteners found in products like diet sodas satiate our desire for sweet tasting foods. The study found when participants imagined a hypothetical lunch, those who were assigned an imaginary diet soda to accompany their food were more likely to choose a savory over sweet snack.
Previous research on the consequences of low calorie sweeteners had found that weight gain appeared to be a consequence of choosing low calorie sweeteners over sugar. But the reasons for these findings are unknown.
Hypotheses include the “sweet taste confusion theory,” that posits those who habitually ingest low-calorie sweeteners adapt to the flavor of sweet carrying very few calories and as a result their body does not help them to stop when they have had enough real sugar. The “sweet tooth” theory suggests that those who take in low calorie sweeteners develop a preference for sweets and so take in more real sugar than they need. The third “compensation” hypothesis says when people use low calorie sweeteners they feel they have saved calories and treat themselves to foods that exceed any calories saved.
Angelica Monge and her colleagues sought to unravel which of these theories may be true.
The research team obtained 332 participants from the freshman psychology class at the University of Bristol. The research was conducted over a three year period. Research participants were asked to imagine a lunch that would include a cheese sandwich and a beverage. They imagined this cheese sandwich alongside five different beverages.
They were told they would eat the cheese sandwich and drink ⅔ of the assigned beverage. Then they were to choose from one of two snacks, M&M’s or peanuts. They were told they would drink the remaining ⅓ of the beverage with the chosen snack.
Participants were also asked if they were habitual soft drink or diet soft drink users. Results revealed that when participants imagined eating the sandwich with a diet soda they did not find evidence for the “sweet taste confusion theory,” or the “sweet tooth” theory. Participants when imagining drinking both diet or regular soft drinks were more likely to pick savory snacks over sweet.
These findings support an alternative “sweet satiation” hypothesis, that when individuals ingest sweet foods they become satisfied and require no more sugar. This effect was the strongest for those who reported they often drank diet soda. The research team suspects this may be because those individuals are conscious of calories to begin with.
Additionally, participants could choose how much of the snack they desired and this data did not support the compensation hypothesis. When imagining drinking a diet soda they were no more likely to increase the amount of snack than in other beverage conditions.
Interestingly data collected from the participants found those who reported they were habitual diet soft drink consumers had a higher BMI than those who drank regular soft drinks or milk. The research team suggest this correlation is likely due to the higher BMI coming before the habitual diet soda drinking, not the other way around.
There were some acknowledged limitations, including the age of participants. The consequence of college freshman drinking diet soda may be different than those who have been ingesting low calorie sweeteners for decades. Finally, although prior research had found imagined eating to be an accurate representation of what people would do in the real world, it is unknown if this is true for this group of participants.
The study, “Consumption of low-calorie sweetened drinks is associated with ‘sweet satiation’, but not with ‘sweet-taste confusion’: A virtual study“, was authored by Angelica Monge, Danielle Ferriday, Simon Heckenmueller, Jeffrey Brunstrum, and Peter Rogers.