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Biomedical subjects

R C Klesges

Publications and source records attributed to R C Klesges.

At least 55 records · Page 3Linked to original sources
PubMed1997

Differences in macronutrient selections in users and nonusers of an oral contraceptive.

One of the problems inherent in using women in clinical research is the effect that oral contraceptive (OC) use might have on physical indexes. Although weight gain is frequently reported as a side effect of OC use, there is little empirical evidence that such weight gain actually occurs. The current study investigated differences in energy balance [ie, dietary intake, resting energy expenditure (REE), and physical activity] between groups of users and nonusers of OCs. Each group completed a protocol that covered one menstrual cycle and consisted of daily recording of dietary intake, measurement of REE once during each phase of the menstrual cycle, and reporting of physical activity over the entire cycle. Comparisons indicate that there was a marginal interaction (P = 0.06) of OC use with total energy intake, indicating a different pattern of intake for the two groups. There were qualitative between-group differences such that the OC group consumed a greater percentage of energy as fat (P = 0.02) and a lesser percentage of energy as carbohydrate (P = 0.008). No group differences were found in the percentage of energy consumed as protein, but both groups consumed significantly less protein during menses (P = 0.008). There were no significant differences in REE. Both groups of women reported marginally more activity (P = 0.09) during menses than during the luteal phase.

Adolescent↗
PubMed1997

Chronic dieting and the belief that smoking controls body weight in a biracial, population-based adolescent sample.

OBJECTIVE: To evaluate the prevalence of weight concerns and smoking for body weight reasons as a function of race and gender. DESIGN: A questionnaire measuring a number of factors thought to be predictive of smoking was administered. SETTING: The Memphis (Tennessee) school system. PARTICIPANTS: Participants were 6961 seventh-grade students (mean age 13 years). This population consisted of 80.8% black children, 16.5% white children, and 2.7% of other ethnic origins. MAIN OUTCOME MEASURES: Weight concerns were assessed using items from a restraint scale. Students were questioned regarding their smoking status, beliefs that smoking controls body weight, and their own weight-control smoking behaviour. RESULTS: Dietary restraint interacted with race in that, whereas white girls scored the highest on dietary restraint, black boys scored higher on dietary restraint than white boys. Almost 40% of subjects at this school level believed that smoking controls their body weight. Of the regular smokers, 12% indicated they have smoked to control their weight, with white girls endorsing this belief significantly more than other respondents. CONCLUSIONS: The propensity to smoke for weight control reasons, previously described by other researchers among white females of college and high-school age, was also found among this sample of students of junior high school age.

Adolescent↗
PubMed1996

Changes in bone mineral content in male athletes. Mechanisms of action and intervention effects.

OBJECTIVES: To determine changes in bone mineral content (BMC) in male athletes, to examine the mechanisms of changes, and to evaluate the effects of intervention. DESIGN: Dual-energy x-ray absorptiometry (DEXA) tests were administered over a 2-year period, and calcium loss during training was determined by analysis of sweat and urine. Calcium supplementation was administered during year 2. SETTING--A midsouth university. PARTICIPANTS: Eleven members of a college Division I-A basketball team. INTERVENTION: Based on observed calcium loss, athletes received differential levels of calcium supplementation. Intervention commenced the week prior to the fall training season and continued through postseason play. MAIN OUTCOME MEASURE--Changes in BMC. RESULTS: Total body BMC decreased 3.8% from preseason to midseason of year 1 (mean decrease, 133.4 g, P = .02), increased nonsignificantly by 1.1% (mean increase, 35.3 g, P = .22) during the offseason, but decreased an additional 3.3% during summer months when practices resumed (mean decrease, 113.1 g, P = .01). Dermal calcium loss averaged 247 mg [corrected] per training session. From preseason to late summer, there was an overall decrease of 6.1% in total BMC and a 10.5% decrease in BMC of the legs. Calcium supplementation was associated with significant increases in BMC and lean body mass. CONCLUSIONS: Bone loss is calcium related and exercise is positively related to BMC provided that calcium intake is sufficient to offset dermal loss.

Absorptiometry, Photon↗
PubMed1996

Precision and estimated accuracy of two short-term food frequency questionnaires compared with recalls and records.

Two widely used food frequency questionnaires (Block FFQ, Willett FFQ) were modified to reflect intake over the past 7 days and compared to intake information gathered from diet records and 24-hr recalls covering the same 7-day period. The Block FFQ and the Willett FFQ were also gathered at the beginning of the assessment period to reflect the 7-day period of time before records and recalls were gathered. Fifty-six subjects were assigned to either recording diet for 3 days, recording diet for 6 days, or providing three 24-hr recalls. Results indicate similar levels of within-method test-retest reliabilities for 3-day RECORDS and 6-day RECORDS, and within the two Block FFQs and within the two Willett FFQs from each subject, while lower reliabilities were seen in 24-hr RECALLS. When the FFQs were compared to the 6-day RECORDS with between-method agreement coefficients, there was a moderate level of agreement, with most values between 0.5 and 0.8 for both FFQs. Significant differences between mean levels of nutrients estimated by the three methods indicated differences only in the estimates of carbohydrate and vitamin A. The use of FFQs to gather short-term intake information is discussed.

Adult↗
PubMed1996

Adolescents' perceptions about smoking prevention strategies: a comparison of the programmes of the American Lung Association and the Tobacco Institute.

OBJECTIVE: To evaluate components of the teenage smoking prevention programmes of the American Lung Association (ALA) and the Tobacco Institute (TI). DESIGN: Group administration of written questionnaires in school. The components of the ALA's and TI's programmes were presented to students in seven strategy vignettes, covering the following topics: peer pressure/enhanced communication; parents as role models; health consequences of smoking; cost of smoking; smoking as an illegal act; tips for quitting smoking; and responsible decision making. SUBJECTS AND SETTING: 172 seventh-grade students (mean age = 12.3 years) from six parochial schools in Memphis, Tennessee, United States. MAIN OUTCOME MEASURES: Student ratings of the perceived effectiveness of the ALA and TI approaches (in helping to stop teens from smoking) within each strategy vignette, and students' choice between these two approaches as to which was the better smoking prevention technique. RESULTS: Although there were some moderating effects of gender and race, participants overall strongly favoured the ALA programme over that of the TI. Of the seven programme components, the ALA's approach was rated more effective on six (peer pressure, parents as role models, the health consequences of smoking, the cost of smoking, tips for quitting smoking, responsible decision making) and the TI's was rated more effective on one (not smoking because it is illegal). CONCLUSIONS: The ALA's programme was perceived to be much more effective than the TI's programme by those whom these programmes are ultimately intended to influence-young people. Future research in this area should pursue longitudinal designs to determine if programme endorsement is predictive of smoking status.

Adolescent↗
PubMed1995

Effects of phenylpropanolamine on withdrawal symptoms.

A prior report (Klesges et al. 1990) suggested that phenylpropanolamine (PPA) was successful in reducing the smoking withdrawal symptom of weight gain in a sample of women. The current investigation evaluates whether the effects of phenylpropanolamine (PPA; up to 10/day PPA gums) on withdrawal symptoms associated with smoking cessation are specific to weight and weight-related symptoms or whether PPA alleviates withdrawal in general. One hundred and seven adult smokers (56 men, 51 women) were randomly assigned, in this double-blind trial, to chew either 8.33 mg phenylpropanolamine gum or a placebo gum. Subjects were then aided to quit smoking for 4 weeks. PPA did not enhance cessation rates. Results from the 47 subjects who successfully quit smoking indicated that postcessation weight gain and ratings of hunger were significantly reduced in both men and women for those assigned to the PPA group relative to the placebo group. Overall, no effects of PPA relative to placebo were observed for other smoking-related withdrawal symptoms. Thus, although PPA appears to reduce weight gain and alleviate weight-related symptoms, no effects on other withdrawal symptoms were observed. Future research directions are suggested.

Adult↗
PubMed1995

Are self-reports of smoking rate biased? Evidence from the Second National Health and Nutrition Examination Survey.

This study determined evidence for digit preference in self-reports of smoking in the Second National Health and Nutrition Examination Survey (NHANES II). Subjects were 4275 adult smokers. Self-reports of smoking showed a marked degree of digit preference, with the vast majority of smokers reporting in multiples of 10 cigarettes per day. When number per day was compared to an objective measure of smoking exposure (carboxyhemoglobin; n = 2070) the distribution was found to be significantly assymetrical. Analysis of the distribution of COHb and various levels of number per day indicates that the differences in distribution are not due to variability in COHb. Heavier smokers, Caucasians, and those with less education were more likely to report a digit preference than lighter smokers. African-Americans, and those with more education. Results suggest that self-reports of number of cigarettes per day may be biased towards round numbers (particularly 20 cigarettes per day). Implications for assessment of smoking behavior are discussed.

Adolescent↗
PubMed1995

Is weight gain after smoking cessation inevitable?

Weight gain after smoking cessation was studied in a naturalistic setting where (1) all smokers quit and (b) risk factors for postcessation weight gain were modified. Participants were 332 military recruits (227 men, 105 women), 86 of whom were smokers who quit during 6 weeks of basic training. Results showed no significant weight changes for smokers who quit. Pretest smoking rates and feat of weight gain were unrelated to changes in weight. Results suggest that an intensive program that limits access to alcohol and foods that are high in fat and that increases physical activity can attenuate weight gain after smoking cessation.

Adolescent↗
PubMed1995

Who underreports dietary intake in a dietary recall? Evidence from the Second National Health and Nutrition Examination Survey.

The present study sought to identify the presence and degree of apparent underreporting of dietary intake in 11,663 participants in the Second National Health and Nutrition Examination Survey (NHANES II). Self-reported dietary intake was compared with estimated basal metabolic rate. Underreporting was based on cutoff limits that identified plausible levels of energy expenditure for adult individuals. Results indicated that up to 31% of adults in this sample may have underreported dietary intake. Those individuals at greatest risk of underreporting were less well educated and heavier. The Sex x Race interaction indicated that for both ethnic categories, women were more likely to underreport than men, but the difference between men and women was greater among Caucasian participants. It is concluded that such factors as reduced energy needs, deliberate falsification, and measurement error inherent in dietary assessment contribute to apparent underreporting, and this occurs in a large percentage of dietary data.

Adolescent↗
PubMed1995

Relationship between obesity and the metabolic effects of smoking in women.

The influence of cigarette smoking on resting energy expenditure (REE) in normal-weight and obese smokers was investigated. Participants were 20 normal-weight and 20 obese female smokers assessed over a 2-day period. The results indicated that REE increased in both obese and normal-weight smokers after smoking, but the increase was greater for normal-weight participants. The normal-weight group showed a 9.7%, 5.8%, and a 3.6% increase in REE during the three 10-min blocks constituting the 30-min postsmoking phase. However, the obese group showed a 3.9% and a 0.7% increase in REE and a 0.8% decrease in REE during this postsmoking phase. Between-group comparisons revealed a differential rate of change in REE after smoking, indicating that the obese group's change of REE at every postsmoking time point was on average 70 kcal/day below that of the normal-weight group. The metabolic effect of smoking is reproducible, and the obese smokers reliably show an attenuated effect. However, the reliability of the change is lower for both normal-weight and obese smokers. The results have potential implications for discouraging obese persons from taking up smoking and intervening among those who already smoke.

Adolescent↗
PubMed1995

The effect of smoking and light activity on metabolism in men.

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.

Adolescent↗
PubMed1995

A longitudinal analysis of accelerated weight gain in preschool children.

The purpose of the current investigation was to determine the dietary, physical activity, family history, and demographic predictors of relative weight change in a cohort of 146 children over a 3-year period. Results indicated that boys of normal-weight parents or who had only one parent overweight showed decreases in their body mass index (BMI) while those with two parents overweight showed increases. Girls with an overweight father showed BMI increases while others experienced decreases in BMI. Additionally, baseline intake of kilocalories from fat as well as decreases in fat intake were related to decreases in BMI. At higher levels of baseline aerobic activity, subsequent changes in BMI decreased. There was also a trend for changes in leisure activity--increases in children's leisure activity was associated with decreases in subsequent weight gain. Modifiable variables (ie, dietary intake, physical activity) accounted for more of the variance in changes in child BMI change than nonmodifiable variables (eg, number of parents obese). These results strongly suggest that encouragement of heart healthy dietary intake patterns and participation in physical activity can decrease accelerated weight gain and obesity, even in preschool children.

Body Mass Index↗
PubMed1995

Predictors of waist circumference change in healthy young adults.

OBJECTIVE: To identify predictors of a change in waist circumference in a group of healthy young adults. SUBJECTS: Caucasian, 121 women and 109 men, participating in a longitudinal investigation of cardiovascular risk factors in parents and their young children. MEASUREMENTS: Evaluations of body weight, waist and hip circumferences, dietary intake, physical activity, cigarette smoking, and alcohol intake were performed annually. Age was recorded and family history of disease was assessed. RESULTS: For women, covariates and modifiable predictors accounted for 67% of the variance in waist circumference change from Year 1 to Year 3. Women with lower baseline waist girths, lower baseline hip girths, higher baseline body weight, and a greater change in body weight had larger increases in waist girth. For men, covariates and modifiable predictors accounted for 72% of the variance in waist circumference change. Men with lower baseline waist girth, a greater change in hip girth, higher baseline body weight, greater increases in body weight, and less percent of fat in the diet at baseline had larger increases in waist girth. Other non-modifiable variables did not predict change in either gender. CONCLUSION: Reducing excess body weight and decreasing weight gain appear to be the most important factors in preventing the accumulation of upper body fat.

Adult↗
PubMed1994

Caffeinated coffee and tea intake and its relationship to cigarette smoking: an analysis of the Second National Health and Nutrition Examination Survey (NHANES II).

Recent studies have shown that smokers' intake of caffeine is higher than nonsmokers. This investigation evaluated the relationships between smoking status and self-reported caffeine intake from both coffee and tea. Subjects were adults who participated in the Second National Health and Nutrition Examination Survey (NHANES II). Results indicated that subjects who ingested caffeine from tea were more likely to be female, less educated, younger, non-Caucasian, and lighter drinkers. In contrast, those who ingested caffeine from coffee were more likely to be older, Caucasian, heavier drinkers, and have higher incomes. Smokers were not more likely to drink caffeinated tea. In contrast, smokers were much more likely to drink caffeinated coffee, and a dose-response relationship between caffeine from coffee and smoking intake was observed. These results clarify the relationship between smoking and caffeine intake. Implications for intervention efforts are discussed.

Adolescent↗
PubMed1994

Effects of alcohol intake on resting energy expenditure in young women social drinkers.

This investigation evaluated the effects of alcohol consumption, controlled for the energy in alcohol and chronic effects of smoking, on resting energy expenditure (REE) in college-aged social drinkers. Sixteen women who both smoked and drank alcohol were administered, on 4 separate days in a counterbalanced order, 1) cigarettes alone, 2) alcohol alone, 3) alcohol plus cigarettes, or 4) cigarettes with an energetic control. Each session consisted of a 25-min REE baseline, treatment in a randomly assigned order, and a 105-min assessment of REE. Analysis indicated that alcohol significantly (P < 0.05) increased REE for up to 95 min after ingestion [increases of 29.6-68.4 kJ (124-287 kcal)/24 h], increases that could not be accounted for by the energy content of the drink alone. Smoking and alcohol together also raised REE above baseline but not more than alcohol alone. It was concluded that alcohol intake raises REE, potentially explaining why alcohol interferes with energy utilization. Potential implications for alcohol intake, nutrition, and weight loss are presented.

Adult↗
PubMed1994

Physicians' diagnosis of obesity status in NHANES II.

The aim of this work was to assess the accuracy of physicians' subjective assessments of obesity status. The subjects were participants in The Second National Health and Nutrition Examination (NHANES II) Survey. The physicians' subjective judgments of obesity were compared to BMI, an objective measure of actual body mass. Subjects with a body mass index (BMI = weight in kg/(height in cm/100)2) less than or equal to 27.5 were classified as normal weight and those with a BMI greater than or equal to 30.4 were considered to be obese. Physicians were accurate in their diagnosis of the normal weight group with only 4.03% being misdiagnosed as obese. However, 12.6% of the obese group was misdiagnosed as normal weight. The odds of an incorrect normal weight diagnosis increased with age. Similarly, as the fat distribution ratio increased, i.e., a more central pattern, the odds of being actually obese but incorrectly diagnosed as normal weight increased. Men were more likely than women to be incorrectly diagnosed as normal weight. Non-Caucasian normal weight persons appear to have been diagnosed more stringently than Caucasians as they were more likely to be misdiagnosed as obese regardless of their gender. There appear to be several variables affecting the physicians' subjective assessment of obesity status in this data set.

Adolescent↗
PubMed1994

Evaluation of the IMPACT blood pressure program.

To evaluate the incremental effectiveness of a work-site blood pressure control program, we conducted a randomized, controlled trial at four work sites with established health promotion programs. Workers with blood pressures of 140/90 mm Hg or higher were eligible. Eighty subjects were assigned to receive a referral to a community physician, monthly 10-minute work-site counseling sessions including blood pressure readings, and personalized mailings, whereas 79 control subjects received only a physician referral. Results for 74 intervention and 71 control subjects were obtained after 1 year. As compared with control subjects, intervention subjects experienced average declines of 8.5/3.9 mm Hg. Adjusted for age, sex, and baseline blood pressure, the decreases were 7.6 mm Hg for systolic and 2.4 mm Hg for diastolic blood pressure. These results suggest that counseling of high-risk persons and personalized mailing programs can have an incremental benefit in controlling blood pressure.

Counseling↗