Obesity after Smoking Cessation – Rationale of a Complex Interplay

By Koji Hasegawa*, Maki Komiyama, Yuko Takahashi

Smoking cessation is one of the most effective ways to reduce cardiovascular disease (CVD) risk. It is astonishing that 7-28% of patients who have survived a coronary heart disease still smoke.1

As one of nicotine withdrawal syndromes, body weight gain and abdominal obesity generally occur after quitting smoking. Obesity results in an increase in various inflammatory markers. Pharmacological treatment by medications such as nicotine patches and varenicline is useful to suppress weight gain during smoking cessation. Weight gain after smoking cessation temporally increases risks of diabetes and reduce the benefit by smoking abstinence.

Does weight gain after quitting smoking help exacerbate CVD?

The α1-antitrypsin–low-density lipoprotein (AT-LDL) complex, a complex of α1-antitrypsin (AT)- oxidised LDL, is an important cardiovascular biomarker. AT-LDL levels have been shown to significantly decrease 3 months after quitting smoking. One year after quitting smoking, the serum AT-LDL levels decreased to a greater extent than the levels 3 months after quitting smoking, regardless of whether obesity increased.2 Thus, long-standing non-smoke will overcome the demerit of weight gain.

A large-scale follow-up study conducted over 30 years examined weight gain after quitting smoking and the subsequent disease risk.3 This study demonstrates that, after an individual quits smoking, his or her risk of death due to CVD and any other cause significantly decreases regardless of weight gain, even if he or she gains ≥10 kg. However, individuals who do not gain weight display greater reduction in the risk of developing CVD than those who gain weight.

A randomised controlled trial examined the timing of instruction in weight management when implementing a smoking cessation intervention.4 According to that trial, the rate of successfully quitting smoking decreased when instructions regarding quitting smoking and managing weight were simultaneously provided from the beginning of the intervention.

Supporting patients to continue smoking cessation is most crucial. Additional management of their weight is clearly beneficial, but should be performed after smoking cessation has been completed.

*Koji Hasegawa
National Hospital Organization Kyoto Medical Center, Kyoto, Japan


  1. Reiner Z. The importance of smoking cessation in patients with coronary heart disease. Int J Cardiol 2018; 258:26-27.
  2. Komiyama M, Shimada S, Wada H, et al. Time-dependent Changes of Atherosclerotic LDL Complexes after Smoking Cessation. J Atheroscler Thromb 2016;23:1270-1275.
  3. Hu Y, Zong G, Liu G, Wang M, Rosner B, Pan A, Willett WC, Manson JE, Hu FB, Sun Q. Smoking Cessation, Weight Change, Type 2 Diabetes, and Mortality. N Engl J Med. 2018 379:623- 632.
  4. Bush T, Lovejoy J, Javitz H, Torres AJ, Wassum K, Tan MM, Spring B. Simultaneous vs. sequential treatment for smoking and weight management in tobacco quitlines: 6 and 12 month outcomes from a randomized trial. BMC Public Health. 2018 May 31;18:678-690.