An honest number
Weight gain after quitting smoking: what the evidence says
The average, the range around it, and what a meta-analysis cannot tell you about yourself.
Written by Lee H. Last reviewed 18 October 2026.
The short answer
On average, people who quit smoking gain about 4 to 5 kg (roughly 9 to 11 lb) over the first year, and most of it arrives in the first three months. That is the mean. Some people lose weight, some gain much more, and nobody can tell you in advance which group you will land in.
The numbers
Aubin et al. pooled 62 studies in the BMJ in 2012. Among people who quit without treatment, the mean weight change from the starting point was:
| Time after quitting | Mean gain |
|---|---|
| 1 month | 1.12 kg (0.76 to 1.47) |
| 2 months | 2.26 kg (1.98 to 2.54) |
| 3 months | 2.85 kg (2.42 to 3.28) |
| 6 months | 4.23 kg (3.69 to 4.77) |
| 12 months | 4.67 kg (3.96 to 5.38) |
The same paper gives the spread at 12 months. Of untreated quitters, about 16% had lost weight, 37% had gained less than 5 kg, 34% had gained 5 to 10 kg and 13% had gained more than 10 kg. The authors also found the figures were similar for people using different medications to quit, and similar for people who were especially worried about weight and people who were not.
What the numbers do not say
- They are averages across studies. The range is the honest part of the result. Your own change could sit anywhere in it.
- They cover up to 12 months. This analysis does not follow weight beyond a year.
- They are not a judgment on whether to quit. Whether and how to weigh a weight change against stopping smoking is a conversation for your doctor, who knows your history. This page will not take a side on it.
Where the app fits
The Long View does not measure weight. What it can do is keep the quit itself in view: the years won back, the money not spent, the health milestones and a daily check-in that records the day as it happened. If a heavier number on the scale is what makes you want to give up on quitting, the craving button is a 3-minute breathing screen with your reason photo on it, and smoking again is covered without judgment.
For the long-run picture, try the life expectancy calculator, and see Premium for what each plan includes.
Common questions
How much weight do people gain after quitting smoking?
In a 2012 BMJ meta-analysis of 62 studies by Aubin et al., people who quit without treatment gained a mean of 4.67 kg (about 10 lb) at 12 months. Most of that came in the first three months. The spread is wide: 16% lost weight and 13% gained more than 10 kg.
Does everyone gain weight?
No. In the same analysis, 16% of untreated quitters had lost weight at 12 months, and 37% had gained less than 5 kg. An average describes a group and says nothing certain about you.
Does The Long View track weight?
No. The app counts cigarettes, smoke-free time, years and money won back, health milestones and your daily check-in. Weight is not among those, so for that question talk to a doctor.
Sources
- Aubin H-J, Farley A, Lycett D, Lahmek P, Aveyard P. "Weight gain in smokers after quitting cigarettes: meta-analysis." BMJ, 2012, 345:e4439. doi.org/10.1136/bmj.e4439
Nothing on this page diagnoses, treats or prevents any condition, and none of it is medical advice. Ask a doctor about weight, nutrition and exercise. No guarantee is made or offered about the accuracy of any figure or calculation on this site. Talk to a doctor or a quitline about stopping. In the US, that is 1-800-QUIT-NOW.
Keep reading
Where to go next
What happens when you quit
A timeline, with the sources and the limits.
Smoked again after quitting
What a slip costs and what it leaves alone.
How many years do you get back?
The four published bands.