Quinine and appetite in a controlled human trial
What it found
In 32 healthy volunteers, quinine taken by mouth or into the stomach did not change how much they ate at a later meal.
It did slightly reduce how much they wanted to eat and how hungry they felt.
What they found
Studies in people
Food intake
The amount eaten at the lunch meal was similar after all four treatments. The authors report no difference in food intake between quinine and placebo.
Desire to eat and hunger
Volunteers reported lower desire to eat and less hunger after tasting quinine in the mouth or after the quinine capsule, compared with placebo. When quinine was given both ways at once, these feelings were not reduced.
Satiation and fullness
Feelings of satiation and fullness did not differ between quinine and placebo.
Heart rate variability
Heart rate variability measurements showed no differences between the quinine and placebo conditions.
Stomach complaints
Stomach pain, bloating and nausea scores were similar across all treatments.
What the authors conclude
“In conclusion, sole oral sham feeding with and sole intragastric delivery of quinine decreased desire to eat and hunger, without affecting food intake, satiation, fullness or HRV.”
Also in their conclusions
- They conclude that oral sham feeding with or intragastric delivery of the bitter tastant quinine decreased desire to eat and hunger feelings, without affecting food intake, feelings of satiation and fullness, and heart rate variability when compared with placebo.
- They suggest that future research should consider the timing between quinine delivery and the test meal, and that long-term effects of tastants on energy intake warrant study.
How it was done
The authors wanted to know whether quinine, a bitter substance, affects eating behaviour differently when tasted in the mouth compared with when it reaches the stomach. Previous studies had looked at quinine delivered further down the gut, but not at these two routes.
Thirty-two healthy volunteers took part in four separate test days, each a week apart. On each day they swallowed a capsule containing quinine or a placebo and also swished a quinine or placebo drink in their mouths without swallowing. Fifty minutes later they were given a large lunch and could eat as much as they wanted.
What it can’t tell you
- This was a single test meal in a controlled laboratory setting, so it cannot show what happens over a whole day or in everyday life with distractions.
- The study did not measure gut hormone levels, so it cannot explain why desire to eat and hunger changed without affecting how much people ate.
Who paid
- Authors work at
- Maastricht University, The Netherlands; Maastricht University Medical Centre, The Netherlands
The paper
- Title
- Effect of oral or intragastric delivery of the bitter tastant quinine on food intake and appetite sensations: a randomised crossover trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Klaassen T, Keszthelyi D, Alleleyn AME, et al (2021). Effect of oral or intragastric delivery of the bitter tastant quinine on food intake and appetite sensations: a randomised crossover trial. The British journal of nutrition. doi:10.1017/S0007114520002536Free full textPubMed 32660667DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error