Skip to content
One of the common justifications smokers offer is concern about weight gain after quitting smoking. Smokers indeed typically have lower body mass compared to non-smokers, but they also tend to have more fat around the abdominal area. Of particular concern is the excess accumulation of visceral fat, which gathers around internal organs such as the liver, pancreas, and intestines. This type of obesity elevates the risk of cardiometabolic disorders, including diabetes, heart attack, and stroke.
Researchers from the Center for Basic Metabolic Research at the University of Copenhagen have investigated the causal relationship between smoking and visceral fat accumulation. The findings were published in the scientific journal Addiction.
Understanding Visceral Fat
Excess visceral fat around the abdomen is a hallmark of metabolic syndrome. It comprises a cluster of disorders including hypertension, obesity, high cholesterol levels, and insulin resistance, collectively increasing the risk of stroke, heart disease, and type 2 diabetes.
Excessive visceral fat is also associated with a higher risk of:
- Dementia
- Certain types of cancer
- Asthma
- Liver and gallbladder diseases
- Fertility issues
- Lower back pain
- Osteoarthritis
By the way, another hazardous habit contributing to visceral fat accumulation is alcohol abuse.
About the Study
To determine whether smoking leads to increased abdominal fat, scientists employed a statistical analysis method called Mendelian randomization. This method combines results from various genetic studies to identify causal relationships between exposure (in this case, smoking) and outcome (abdominal fat increase). Overall, the authors analyzed studies involving 1.2 million individuals who recently started smoking and over 450,000 long-term smokers. The research on body fat distribution encompassed more than 600,000 individuals.
Analyzing previous genetic studies, the authors identified genes associated with smoking habits and fat distribution in the body. They found that the fat distribution in smokers typically differs from that of non-smokers. Additionally, they accounted for other factors such as alcohol consumption and socioeconomic status to exclude their influence on fat distribution.
Results: Smoking Contributes to the Accumulation of Visceral Fat
The risk of accumulating abdominal fat, especially visceral fat, increases even if an individual has recently started smoking.
This study found that starting to smoke and smoking over a lifetime might cause an increase in belly fat, as seen by measurements of waist-to-hip ratio. In a further analysis, we also found that the type of fat that increases is more likely the visceral fat, rather than the fat just under the skin.
Dr. Germán D. Carrasquilla, Lead Author
The authors believe that their findings underscore the importance of widespread efforts to prevent and reduce smoking among the population. Eliminating this harmful habit represents a significant step towards long-term health, and new evidence confirms this.
Scientists plan further studies to determine how fat distribution changes after smoking cessation. Additionally, the analysis only included individuals of European descent, so it is necessary to analyze the genetic information of non-European smokers.
