ABSTRACT
This experiment examined the metabolic effects of smoking during rest and light activity under naturalistic conditions. Thirty-nine male subjects first completed a submaximal graded exercise treadmill test to standardize activity level. Then 3 groups of subjects--smokers smoking (SS), smokers not smoking (SNS), and nonsmokers (NS)--were exposed to 3 stages of rest or 3 stages of light activity with order of rest or activity randomly determined over 2 different days. Energy expenditure was monitored continuously during these sessions. Significant increases in smokers' energy expenditure were observed during light activity when compared with smokers not smoking and nonsmokers. No differences were identified among groups at rest. These findings strengthen the conclusion that smoking or its components contribute to metabolic changes during typical levels of daily activity and suggest a mechanism for the frequently observed relationship between smoking status and body weight.
Subject(s)
Energy Metabolism/drug effects , Exercise/physiology , Smoking/physiopathology , Adolescent , Adult , Body Weight/drug effects , Body Weight/physiology , Energy Metabolism/physiology , Humans , Male , Nicotine/administration & dosage , Reference ValuesABSTRACT
Estimates of postcessation weight gain vary widely. This study determined the magnitude of weight gain in a cohort using both point prevalence and continuous abstinence criteria for cessation. Participants were 196 volunteers who participated in a smoking cessation program and who either continuously smoked (n = 118), were continuously abstinent (n = 51), or who were point prevalent abstinent (n = 27) (i.e., quit at the 1-year follow-up visit but not at others). Continuously abstinent participants gained over 13 lbs. (5.90 kg) at 1 year, significantly more than continuously smoking (M = 2.4 lb.) and point prevalent abstinent participants (M = 6.7 lbs., or 3.04 kg). Individual growth curve analysis confirmed that weight gain and the rate of weight gain (pounds per month) were greater among continuously smoking participants and that these effects were independent of gender, baseline weight, smoking and dieting history, age, and education. Results suggest that studies using point prevalence abstinence to estimate postcessation weight gain may be underestimating postcessation weight gain.
Subject(s)
Smoking Cessation , Weight Gain , Adult , Analysis of Variance , Chi-Square Distribution , Confidence Intervals , Female , Humans , Male , Middle Aged , Prospective Studies , Recurrence , Time FactorsABSTRACT
This study evaluates the longitudinal relationships among smoking and adiposity, dietary intake, and physical activity in a group of adult males. Subjects were 101 nonsmokers and 19 regular cigarette smokers. Adiposity, dietary intake, and physical activity were assessed annually for three consecutive years. Results indicated that nonsmokers had larger tricep skinfold measurements than smokers over the 3-year period. However, dietary intake and physical activity did not differ between groups. Due to the absence of differences on these two variables for the smoking and nonsmoking groups, it was concluded that the lower adiposity in smokers was largely metabolically determined, which may make difficult the treatment of postcessation weight gain.