Cigarette smoking can dramatically affect appetite and weight control

Nov 1 2004

Cigarette smoking can dramatically affect appetite and weight control, and disrupts the body’s natural energy balance, a study by University of Melbourne researchers has found.

The study by researchers in the Department of Pharmacology and the CRC for Chronic Inflammatory Diseases found that mice exposed to four days of cigarette smoke displayed significant loss of appetite, fat tissue and body weight.

The results of the study will be published later this month in the journal Neuropsychopharmacology.

The loss of body weight observed in mice exposed to smoke from cigarettes three times a day for four consecutive days was associated with a negative energy balance and increased use of fat stores.

Lead researcher, Associate Professor Margaret Morris (Pharmacology) says “after just one day of exposure to the smoke, food intake had already started to decrease. This continued, such that over the trial, food intake in the smoke-exposed mice was 30% less than the control mice and their body weight had reduced by about 10%.”

Along with reduced food intake, the expression of a protein called UCP3 was found to be significantly increased in fat tissue following smoke exposure.

Associate Professor Morris says “an increase in UCP3 suggests that in the smoke exposed mice, the use of fat and energy expenditure was increased, disrupting the body’s internal equilibrium.”

“Normally, the brain responds to a negative energy balance by stimulating appetite pathways in the brain and adjusting food intake or reducing energy expenditure. In the smoke exposed mice, rather than decreasing energy expenditure, it appeared to increase, along with increased use of the fat stores.”

The smoke exposed mice also showed changes to their internal organs – the livers of these mice were significantly lighter than those of the control mice.

Associate Professor Morris says “some people are willing to use smoking in order to maintain their body weight and are often reluctant to stop smoking due to concerns about weight gain. This is especially true among younger smokers.

“But the effects of cigarette smoking on appetite may also contribute to the morbidity and mortality of smokers with chronic lung disease and wasting. Smoking is a major risk factor for a number of diseases and contributes to approximately 10% of deaths in our community.”