The short answer
Tirzepatide reduced food intake at a test lunch and improved several appetite questionnaires. A short laboratory study cannot tell us exactly how someone will eat every day.
Who was studied?
Researchers randomized 114 adults without diabetes to tirzepatide, placebo or liraglutide. Tirzepatide and placebo were blinded; liraglutide was open-label.
The tirzepatide group received 5 mg for three weeks, then 10 mg for three weeks—a study regimen, not starting-dose guidance.
One meal, not a daily calorie deficit
Estimated between-group difference
−524.6 kcal
Randomized participants
114 across three groups
Original visual based on the study.
| Group or measure | Result |
|---|---|
| Estimated between-group difference | −524.6 kcal |
| Randomized participants | 114 across three groups |
What changed?
At week three, the change in calories consumed at the test lunch was 524.6 kcal lower with tirzepatide than placebo. This was one meal, not a measured daily calorie deficit.
Participants also reported less hunger and fewer cravings. These secondary comparisons were not adjusted for multiple testing.
What were the trade-offs?
Digestive symptoms were common. Three of 37 tirzepatide participants stopped because of adverse events: nausea, pancreatitis and vomiting.
The useful takeaway
The findings help explain appetite changes people describe. The trial was small, short and mostly female, so it cannot predict everyone's long-term experience.
Sources
Martin and colleagues, Nature Medicine, 2025. Funded by Eli Lilly.