Why is smoking beneficial for overweight people?

Smoking, or nicotine, causes increased dopamine and serotonin release. Both neurotransmitters act as appetite suppressants (especially for sweets), so that on the one hand smokers tend to consume fewer calories than non-smokers. On the other hand, nicotine also increases the basal metabolic rate, i.e. smokers burn 4-16% more calories than non-smokers. Smokers, for example, have an average body weight of 3 - 5% lower than that of non-smokers.

But there are also, increasingly, overweight smokers. Overweight smokers make fewer attempts to quit and have more relapses. They also tend to gain more weight when they quit smoking. Heavy smokers have an unfavorable fat distribution, namely increased visceral fat, or the so-called "apple shape".

COPD patients are often undernourished and malnourished, up to so-called "pulmonary cachexia". In their case, weight gain is even desirable.

Quitting smoking and gaining weight

The majority of people who quit smoking gain weight, averaging 4 to 5 kg (4.7 kg). However, the range of weight gain is wide:

• 16% decrease
• 37% gain weight less than 5 kg
• 34% gain 5-10 kg
• 13% gain weight more than 10 kg

Weight gain occurs after the acute phase of smoking cessation, i.e. after 2-4 weeks.

The ex-smoker would have to gain over 50 kilos to create a health risk comparable to cigarette smoking.

The reasons are, on the one hand, that the need for calories decreases after quitting smoking (see above), on the other hand, increased appetite is one of the nicotine withdrawal symptoms. Most of the weight gain (69%) can be explained by an increased calorie intake.

Gender specific weight gain

Women smoke more than men to control their weight and are more likely to say they would not tolerate weight gain after quitting smoking. This is probably one of the reasons why women try to quit smoking less often. On average, women gain more weight than men.

There are several ways to counteract weight gain:

  • reduce calorie intake;
  • burn more calories, i.e. increased exercise and sport;
  • Using medication to quit smoking: Medications containing nicotine (especially chewing gum 4 mg and lozenge and sublingual tablets (microtab) 2 mg) seem to be effective in delaying weight gain after quitting smoking if they are used in high enough doses. Bupropion (Zyban®) also delays weight gain after quitting smoking. After stopping these medications, however, ex-smokers gain on average the same weight that they would have gained without medication.
  • Nutritional advice, coaching, behavior therapy.

The potential for weight gain should not be a reason to continue smoking, as the risks of smoking far outweigh the risks of being slightly overweight. The fear of gaining weight is often worse than actually gaining weight.

Aubin H-J et al, Weight gain in smokers after quitting cigarettes: meta-analysis. BMJ 2012; 345 doi: 10.1136 / bmj.e4439 (published 10 July 2012)

Eisenberg D, Quinn BC. Estimating the effect of smoking cessation on weight gain: an instrumental variable approach. Health Serv Res 2006; 41: 2255-66.

John U, Meyer C, Rumpf HJ, et al. No considerable long-term weight gain after smoking cessation: evidence from a prospective study. Eur J Cancer Prev 2005; 14: 289-95.

Klesges RC, Winders SE, Meyers AW, et al. How much weight gain occurs following smoking cessation? A comparison of weight gain using both continuous and point prevalence abstinence. J Consult Clin Psychol 1997; 65: 286-91.

O'Hara P, Connett JE, Lee WW, et al. Early and late weight gain following smoking cessation in the Lung Health Study. Am J Epidemiol 1998; 148: 821-30.

Williamson DF, Madans J, Anda RF, et al. Smoking cessation and severity of weight gain in a national cohort. N Engl J Med 1991; 324: 739-45.

Filozof C, Fernandez Pinilla MC, Fernandez-Cruz A. Smoking cessation and weight gain. Obes Rev 2004; 5: 95-103.

Gray CL, Cinciripini PM, Cinciripini LG. The relationship of gender, diet patterns, and body type to weight change following smoking reduction: a multivariate approach. J Subst Abuse 1995; 7: 405-23.

Munafo MR, Murphy MF, Johnstone EC. Smoking cessation, weight gain, and DRD4 -521 genotype. Am J Med Genet B Neuropsychiatr Genet 2006; 141: 398-402.

Pisinger C, Jorgensen T. Waist circumference and weight following smoking cessation in a general population: the Inter99 study. Prev Med 2007; 44: 290-5.

Allen SS, Hatsukami D, Brintnell DM, et al. Effect of nicotine replacement therapy on post-cessation weight gain and nutrient intake: a randomized controlled trial of postmenopausal female smokers. Addict Behav 2005; 30: 1273-80.

Hill AL, Roe DJ, Taren DL, et al. Efficacy of transdermal nicotine in reducing post-cessation weight gain in a Hispanic sample. Nicotine Tob Res 2000; 2: 247-53.

Ahluwalia JS, Harris KJ, Catley D, et al. Sustained-release bupropion for smoking cessation in African Americans: a randomized controlled trial. JAMA 2002; 288: 468-74.

Assali AR, Beigel Y, Schreibman R, et al. Weight gain and insulin resistance during nicotine replacement therapy. Clin Cardiol 1999; 22: 357-60.

Hurt RD, Sachs DP, Glover ED, et al. A comparison of sustained-release bupropion and placebo for smoking cessation. N Engl J Med 1997; 337: 1195-202.

Nides M, Rand C, Dolce J, et al. Weight gain as a function of smoking cessation and 2-mg nicotine gum use among middle-aged smokers with mild lung impairment in the first 2 years of the Lung Health Study. Health Psychol 1994; 13: 354-61.