Background: Vinegar is promoted as a natural appetite suppressant, based on previous reports that vinegar ingestion significantly increases subsequent satiety. However there are concerns about the appropriateness and safety of this advice, and it is unclear if poor product palatability may explain previously published effects on appetite.

Objective: To investigate if vinegar palatability and tolerability have a role in suppressing appetite and food intake in two sequential and related acute human feeding studies.

Subjects and methods: Healthy, young, normal weight unrestrained eaters were recruited to Study 1 (n=16), an acute feeding study supplying vinegar within both palatable and unpalatable drinks alongside a mixed breakfast in comparison to a non-vinegar control; and to Study 2 (n=14), a modified sham feeding study (taste only without ingestion) comparing vinegar to a non-vinegar control following a milkshake preload. Both studies were a randomized crossover balanced design for the assessment of appetite, energy intake and glycaemic response.

Results: In Study 1, ingestion of vinegar significantly reduced quantitative and subjective measures of appetite, which were accompanied by significantly higher nausea ratings, with unpalatable treatment having the greatest effect. Significant correlations between palatability ratings and appetite measures were found. In Study 2, orosensory stimulation with vinegar did not influence subsequent subjective or quantitative measures of appetite compared with control.

Conclusions: These studies indicate that vinegar ingestion enhances satiety whereas orosensory stimulation alone does not, and that these effects are largely due to poor tolerability following ingestion invoking feelings of nausea. On this basis the promotion of vinegar as a natural appetite suppressant does not seem appropriate.