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D F Williamson

Publications and source records attributed to D F Williamson.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effects of question order on estimates of the prevalence of attempted weight loss.

Although numerous surveys have been conducted to estimate the prevalence of attempted weight loss, little information is available on the possible effects of question order on the prevalence estimates. The authors examined data collected from 231,852 respondents to surveys conducted in the District of Columbia and 20 states that participated in the Behavioral Risk Factor Surveillance System between 1985 and 1992. In surveys conducted from 1985 to 1988, respondents (n = 117,827) were first asked their body weight and then were asked if they were trying to lose weight; 48% of the women and 29% of the men reported that they were trying to lose weight. In 1989, 1991, and 1992 (no questions about weight control were asked in 1990), the order of the questions was reversed so that respondents (n = 114,025) were asked whether they were trying to lose weight before they were asked to report their weight; 41% of the women and 26% of the men reported that they were trying to lose weight. The authors conclude that survey respondents, especially women, may be more likely to report that they are trying to lose weight when questions about weight control practices immediately follow questions on current weight. This apparent effect of question order points to the need for caution in comparing prevalence estimates across surveys in which the questions are not asked in a similar order, even when the questions are worded identically.

Adult↗
PubMed1995

Prospective study of intentional weight loss and mortality in never-smoking overweight US white women aged 40-64 years.

Although 40% of US women indicate they are currently trying to lose weight, the association between intentional weight loss and longevity is unknown. The authors analyzed prospective data from 43,457 overweight, never-smoking US white women aged 40-64 years who in 1959-1960 completed a questionnaire that included questions on weight change direction, amount, time interval, and intentionality. Vital status was determined in 1972. Proportional hazards regression was used to estimate mortality rate ratios for women who intentionally lost weight compared with women who had no change in weight. Women who died within the first 3 years of follow-up were excluded. Analyses were stratified by preexisting illness and adjusted for age, beginning body mass index, alcohol intake, education, physical activity, and health conditions. In women with obesity-related health conditions (n = 15,069), intentional weight loss of any amount was associated with a 20% reduction in all-cause mortality, primarily due to a 40-50% reduction in mortality from obesity-related cancers; diabetes-associated mortality was also reduced by 30-40% in those who intentionally lost weight. In women with no preexisting illness (n = 28,388), intentional weight loss of > or = 20 lb (> or = 9.1 kg) that occurred within the previous year was associated with about a 25% reduction in all-cause, cardiovascular, and cancer mortality; however, loss of < 20 lb (< 9.1 kg) or loss that occurred over an interval of > or = 1 year was generally associated with small to modest increases in mortality. The association between intentional weight loss and longevity in middle-aged overweight women appears to depend on their health status. Intentional weight loss among women with obesity-related conditions is generally associated with decreased premature mortality, whereas among women with no preexisting illness, the association is equivocal.

Adult↗
PubMed1995

Relation of serum uric acid to mortality and ischemic heart disease. The NHANES I Epidemiologic Follow-up Study.

Although hyperuricemia is frequently found among persons with ischemic heart disease, its importance as a risk factor remains uncertain. The authors examined this relation among 5,421 persons in the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study; baseline data were collected in 1971-1975 and follow-up was through 1987. No associations were seen among men, but, among women, the serum uric acid level was predictive of mortality from all causes and from ischemic heart disease. These associations persisted even after excluding the first 10 years of follow-up and were independent of use of antihypertensive agents and diuretics, diastolic blood pressure, overweight, and other characteristics. A dose-response relation was evident for mortality from ischemic heart disease: each 1-mg/dl change in uric acid (about two thirds of the standard deviation) among women increased the rate by 1.48 (95% confidence interval 1.3-1.7). Furthermore, as compared with women who had a uric acid level < 4 mg/dl, those with a level > or = 7 mg/dl had a 4.8-fold (95% confidence interval 1.9-12) higher rate of ischemic heart disease mortality. In contrast, the uric acid level showed a weaker relation with disease incidence among women, with a rate ratio of 1.14 for each 1-mg/dl change. Although the biologic mechanism is unclear, further investigation into the possible role of uric acid in the development of ischemic heart disease is needed.

Adult↗
PubMed1995

History of intentional and unintentional weight loss in a population-based sample of women aged 55 to 69 years.

Although both overweight and body weight fluctuation are related to chronic disease risk, little is known about the history of and reasons for body weight change in the general population. This paper reports the incidence of intentional and unintentional weight loss episodes during adulthood in a population-based sample of 26,261 women aged 55 to 69 years. Intentional weight loss episodes of each of four amounts (5-9, 10-19, 20-49, 50+ lbs.) and unintentional weight loss episodes of 20 or more lbs. were recalled for each of three age periods (18-39, 40-54, 55+ years). At least one intentional weight loss episode of 5 or more lbs. was reported by 69% of women, 46% reported at least one intentional weight loss episode of 10 or more lbs, and 25% reported at least one intentional weight loss episode 20 or more lbs. At least one unintentional weight loss episode of 20 or more lbs. was reported by 29% of the women. Reasons for weight losses of 20 or more lbs. were also recalled. Women who had intentionally lost 20 or more lbs. were more likely to report weight losses due to low-calorie diets, exercise and weight loss groups, while women who had unintentionally lost 20 or more lbs. were more likely to report weight losses due to depression or stress. These findings question the common assumption that weight losses in adult women are primarily intentional and emphasize the need to distinguish the reasons for weight loss in studies examining the relationship between body weight changes and health outcomes.

Aged↗
PubMed1995

The validity of self-reports of past body weights by U.S. adults.

Past weight or patterns of weight change may be more important to chronic disease risk than current weight. Self-reports, however, are often the only source of information about past body weight. To date, very few studies have examined factors affecting the validity of self-reported past body weight. We examined the validity of self-reported past body weights of 1,931 U.S. adults who were participants in the First National Health and Nutrition Examination Survey (1971-1975) and were interviewed again in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study (1982-1984). We compared the body weight measured during the initial examination (1971-1975) with the recalled 1971-1975 body weight reported during the follow-up interview (1982-1984). Recalled past weight was strongly correlated with previously measured weight (r = 0.73 for men, and r = 0.74 for women). Men overestimated their past body weight, whereas women underestimated their past weight. Although 39% of men and 41% of women estimated their past weight within 5 pounds, approximately 17% of women and 10% of men underestimated their past weight more than 15 pounds. Accuracy of reporting was influenced by sex, race, current body mass index, and the amount of weight gained over the 10 years following the initial examination. These factors should be considered when using recalled weight in epidemiologic studies.

Adult↗
PubMed1995

Alcohol intake and subsequent mortality: findings from the NHANES I Follow-up Study.

OBJECTIVE: Because past research has focused primarily on populations of middle-aged men, the relationship between alcohol and mortality among women and the elderly has been less well substantiated METHOD: We examined the relationship between alcohol intake and mortality using data from the NHANES I Epidemiologic Follow-Up Study. Total mortality was examined for both sexes (N = 4,614 women, 3,573 men), but ischemic heart disease (IHD) mortality was examined only for men because the number of deaths was too small in women. Proportional hazards modeling was used to adjust for the baseline characteristics of age, race, education, body weight, smoking and physical activity. RESULTS: For men aged 40 to 64, the adjusted relative risks (RR) of death for drinking levels of .5 drinks/day, .5 to < 2 and > or = 2 (compared to the nondrinking reference group) were 0.8 (95% Confidence Interval: 0.6, 1.1), 0.9 (CI:0.6, 1.2) and 1.2 (CI: 0.9, 1.6); RRs of IHD mortality were 0.6 (CI: 0.4, 0.9), 0.5 (CI: 0.3, 0.9) and 0.7 (CI: 0.5, 1.2). For women aged 40 to 64, the RRs for death for the same exposure categories were 1.2 (CI: 0.9, 1.6), 0.9 (CI: 0.6, 1.4) and 1.9 (CI: 1.2, 3.0). Among both sexes 65 years and older, consumption of < 2 drinks/day was associated with about a 20% decrease in total mortality and IHD mortality (men only). However, this protective effect disappeared after exclusion of those with pre-existing disease. CONCLUSIONS: Our findings support a protective effect of moderate alcohol intake on IHD mortality in middle-aged men. Among both men and women, there was little evidence of a protective association between moderate alcohol intake and total mortality after excluding those with pre-existing disease.

Adult↗
PubMed1995

Weight variability in a population-based sample of older women: reliability and intercorrelation of measures.

Six measures of weight variability were examined in a cohort of 29,015 postmenopausal women. Recalled weight at ages 18, 30, 40 and 50 years, current weight at baseline and at each of three biennial follow ups (approximate ages 62, 64, 66, 68 years), and recalled episodes of intentional and unintentional weight loss were used to construct (1) the coefficient of variation (CV) in body weight, (2) weight change categories (cycling, weight gain, weight loss and stable weight), (3) the root mean square error of variation (RMSE) around the slope of weight versus age, (4) the number of intentional weight loss episodes of 5 or more pounds, (5) the number of unintentional weight loss episodes of 20 or more pounds and (6) a categorical measure of intentional and unintentional weight loss episodes of > = 20 lb. The nine-month test-retest reliability correlations for the measures of lifetime history of intentional and unintentional weight loss were 0.80 and 0.62, respectively. Correlations between the different weight variability measures were positive but weak, suggesting that they reflect different aspects of weight variability. The RMSE discriminated categorically defined cyclers from weight gainers, but the CV did not. The weight change categories were more sensitive to age-related weight changes than the CV or RMSE. Studies examining the relationship between weight variability and health outcomes need to include measures that distinguish intentionality, short-term versus long term variability, and the magnitude, direction, and frequency of weight change.

Aged↗
PubMed1995

Can the Year 2000 objective for reducing overweight in the United States be reached?: a simulation study of the required changes in body weight.

AIM: The purpose of this analysis was to estimate the magnitude of weight change required in the six-year period between 1994 and the Year 2000 if Americans are to reach the Healthy People 2000 goal for reduction of overweight among those ages 20-74 to no more than 20% among all adults and no more than 30% among black women. Prevention of weight gain among the non-overweight is compared with that of weight loss among the overweight as strategies for reaching this goal. DESIGN: Data from the First National Health and Nutrition Examination Survey (NHANES I) and the Nutrition Examination Survey Epidemiologic Follow-up Study (NHEFS) were used to estimate 6-year weight change of persons aged 20 to 72 at the Year 2000. Men, white women, and black women were examined in addition to the overall population. Given a baseline prevalence of 24.7%, overweight in the year 2000 was projected for three simulated interventions: no weight gain among non-overweight persons (prevention-only), weight loss among overweight persons (weight-loss-only), and prevention-plus-weight-loss. In addition, the Year 2000 overweight prevalence was projected under different baseline prevalence scenarios of 26% and 34%. OUTCOME MEASURE: Prevalence of overweight; overweight determined by body mass index (> or = 27.3 kg/m2 for women and > or = 27.8 kg/m2 for men). RESULTS: Prevention-only was successful in reducing the overall prevalence of overweight from 24.7% to 20%. Weight-loss-only required a 5.3 kg weight loss to achieve the overall goal of 20% and 8.4 kg weight loss to achieve the goal within all three race-sex strata. Prevention-plus-weight-loss required only 3.8 kg of weight loss to achieve the goals within the three race-sex strata. Prevention-only was not successful in reducing the overall prevalence of overweight to 20% when the 26% and 34% baseline scenarios were used. Weight-loss-only required 6.3 and 11.2 kg; prevention-plus-weight-loss required 1.2 and 6.6 kg of weight loss using the 26% and 34% baselines, respectively. CONCLUSIONS: Prevention of weight gain among those who are not already overweight could achieve substantial changes in the prevalence of overweight, even in a 6-year time period. However, given the increasing trend in overweight, the Year 2000 goal for the reduction in prevalence of overweight will not be reached.

Adult↗
PubMed1994

A prospective study of alcohol intake and change in body weight among US adults.

Little is known about the role of alcohol in determining change in body weight. In this paper, the authors examine the relation between alcohol intake and body weight in 7,230 US adults aged 25-74 years who participated in the First National Health and Nutrition Examination Survey (1971-1975) and who were reweighed 10 years later (1982-1984). Both cross-sectional and prospective analyses were adjusted for age, race, height, education, health status, smoking status, diet status, physical activity, and total nonalcoholic caloric intake. At baseline, women who reported at least one drink per day weighed 2.3 kg less than nondrinkers (95% confidence interval (CI) -0.4 to -4.2). Little relation was observed between body weight and alcohol intake cross-sectionally among men. Prospectively, both men and women drinkers tended to gain less weight than did nondrinkers (p = 0.006 for trend in women, p = 0.11 for trend in men). Drinkers also had more stable weight over the 10-year follow-up period. Drinkers were less likely to have major weight gain or loss (gaining or losing > or = 10 kg) than were nondrinkers. Compared with nondrinkers, for those who consumed 1-6.9 drinks per week, women had an odds ratio (OR) = 0.7 (95% CI 0.5 to 0.9) for major weight gain and an OR = 0.7 (95% CI 0.5 to 1.1) for major weight loss, while men had an OR = 1.0 (95% CI 0.6 to 1.6) for major weight gain and an OR = 0.7 (95% CI 0.5 to 1.2) for major weight loss. For those who consumed > or = 2 drinks per day, women had an OR = 0.5 (95% CI 0.3 to 1.0) for major weight gain and an OR = 0.8 (95% CI 0.4 to 1.6) for major weight loss, while men had an OR = 0.9 (95% CI 0.5 to 1.6) for major weight gain and an OR = 1.0 (95% CI 0.6 to 1.7) for major weight loss. These data suggest that alcohol intake does not increase the risk of obesity.

Adult↗
PubMed1994

Trends in oral contraceptive use and cigarette smoking. Behavioral Risk Factor Surveillance System, 1982 and 1988.

OBJECTIVE: To investigate trends in oral contraceptive (OC) use and smoking among women of reproductive age and to determine factors related to smoking among OC users. DESIGN, SETTING, AND PARTICIPANTS: Telephone interviews of women aged 18 through 45 years in 16 states and the District of Columbia who participated in the Behavioral Risk Factor Surveillance System in 1982 (N = 3553) and in 1988 (N = 7384). RESULTS: Between 1982 and 1988, the prevalence of smoking decreased from 31% to 24% among OC users and from 32% to 28% among non-OC users. In both 1982 and 1988, more than half of the OC users who smoked were heavy smokers (smoked 15 or more cigarettes per day). Nearly one fourth of 35- to 45-year-old women who used OCs were smokers. After we standardized for age, race, and education, the decline in the prevalence of smoking among OC users did not differ substantially from the decline in smoking among non-OC users. CONCLUSIONS: Despite the possible synergistic effects of smoking and OC use on the risk of cardiovascular disease, we found no accelerated decline in the prevalence of smoking among OC users. As of 1988, nearly one fourth of all OC users were smokers. These data emphasize the need to reduce the prevalence of smoking among women who use OCs before they reach the age at which their risk for cardiovascular disease increases substantially.

Adolescent↗
PubMed1994

Weight control practices in adults: results of a multistate telephone survey.

In this study, data collected in 1989 in a random-digit dialing telephone survey of 60,590 adults in 38 states and the District of Columbia were analyzed. Approximately 38% of women and 24% of men reported that they were currently trying to lose weight. Methods reported were counting calories (24% of women, 14% of men), participating in organized weight loss programs (10%, 3%), taking special supplements (10%, 7%), taking diet pills (4%, 2%), and fasting for 24 hours or longer (5%, 5%). Among both sexes, only half of those trying to lose weight reported using the recommended method of caloric restriction combined with physical activity.

Adolescent↗
PubMed1994

Abdominal obesity and mortality risk among men in nineteenth-century North America.

The health consequences of an adverse body-fat distribution (e.g., android, upper-body, visceral) have only recently concerned the medical community. Ninety years ago, however, actuarial study demonstrated the relationship of body-fat distribution to the mortality experience of insured, North American men. Thirty-four insurance companies pooled their data on males issued life policies between 1870 and 1899. Special classes of risk were defined by weight for height at baseline or by the observation that abdominal girth exceeded the girth of the expanded chest (abdominal obesity). The mortality experience of each risk class was compared to an age-stratified, actuarial table of the period. We present new analyses of these historical data relating specifically to the mortality impact of abdominal obesity. Among 163,567 overweight men, the prevalence of abdominal obesity increased with age and with degree of overweight. Among moderately overweight men, those with abdominal obesity experienced 133% of the expected mortality rate compared to 112% of the expected mortality for those who were not abdominally obese. Severely overweight men with abdominal obesity experienced 152% of the expected mortality compared to 135% of the expected mortality for severely overweight men who were not abdominally obese. We believe this nineteenth-century, acturial study of waist and chest girths was the first demonstration that body-fat distribution can influence longevity. These early actuarial findings, taken with more recent reports, establish that abdominal enlargement, but not necessarily an 'upper-body' fat distribution, constitutes a major health hazard. Future research must establish which abdominal-obesity index best predicts disease outcomes.

Abdomen↗
PubMed1994

A prospective study of childbearing and 10-year weight gain in US white women 25 to 45 years of age.

Although birth rates to US women aged 25 and older have increased markedly over the last two decades, accurate estimates of the long-term weight gain associated with childbearing are not available for older mothers in the general population. We examined the effect of childbearing on weight change in 2547 white women aged 25-45 years who were initially weighed in the First National Health and Nutrition Examination Survey (1971-75) and who were reweighed an average of 10 years later. Linear and logistic regression estimates were adjusted for duration of follow-up, age, body mass index, initial parity, education, smoking, drinking, employment status, marital status, illness, physical activity, and dieting to lose weight. Compared to parous women who did not give birth during the study period, the mean excess weight gain was 1.6 kg (95% Confidence Limits, +/- 2.3 kg) for nulliparous women, and was 1.7 kg (+/- 1.1 kg), 1.7 kg (+/- 2.0 kg), and 2.2 kg (+/- 4.3 kg), for women having one, two and three live births, respectively. Among women who were nulliparous at baseline, those that had their live births during the study period gained similar amounts of weight to that of women who began childbearing before the beginning of the study. The risk of gaining more than 13 kg was increased by 40%-60%, and the risk of becoming overweight was increased by 60%-110% in women having live births during the study. We conclude that the average weight gain associated with childbearing after the age of 25 is quite modest in US white women. However, for some women who give birth after the age of 25 the risks of major weight gain and becoming overweight are increased in association wtih childbearing.

Adult↗
PubMed1993

Descriptive epidemiology of body weight and weight change in U.S. adults.

Data on body weight and weight change collected from nationally representative samples of U.S. adults are reviewed. The body mass index (weight [kg]/height [m2]) has a low correlation with height and is used to compare body weights between persons of differing heights. The BMI varies to a greater degree in women than in men. Below the 75th percentile of the BMI distribution, women have lower BMIs than men, whereas at the 75th percentile and above, women have higher BMIs than men. Overweight is defined as a BMI of 27.8 or more in men and of 27.3 or more in women, corresponding to approximately 20% or more above desirable weight in the 1983 Metropolitan Life Insurance Company tables. For persons of average height (men, 5'9"; women, 5'4") this definition is equivalent to a body weight above 85 kg (187 pounds) in men and above 72 kg (158 pounds) in women. Among adults 20 to 74 years of age, 24% of men and 27% of women are overweight, yielding an estimated total of 34 million persons in the United States. The prevalence of overweight increases with age, for both men and women but to a greater degree in women. Blacks and Hispanics have a higher prevalence of overweight than do whites, especially among women. Between 1960 and 1980, the prevalence of overweight among whites increased by 3% in women and by 6% in men. In blacks, however, the prevalence of overweight increased by 7% in women and by 28% in men. Longitudinal body weight measurements taken 10 years apart show that adults younger than 55 years tend to gain weight, whereas those 55 years and older tend to lose weight. The youngest adults gain the most weight, and the oldest adults lose the most weight. In all age groups, women have substantially greater variation in their 10-year weight change than do men.

Adult↗
PubMed1993

Weight control practices of U.S. adolescents and adults.

OBJECTIVE: To estimate the prevalence of various weight-loss practices in U.S. adolescents and adults. DESIGN: The Youth Risk Behavior Survey, a self-administered survey of a random sample of high school students in 1990 and the Behavioral Risk Factor Surveillance System, a random-digit dial survey in 1989. SETTING: Thirty-eight states and the District of Columbia. PARTICIPANTS: High school students (n = 11,467) and adults 18 years and older (n = 60,861). RESULTS: Among high school students, 44% of female students and 15% of male students reported that they were trying to lose weight. An additional 26% of female students and 15% of male students reported that they were trying to keep from gaining more weight. Students reported that they had used the following weight control methods in the 7 days preceding the survey: exercise (51% of female students and 30% of male students); skipping meals (49% and 18%, respectively); taking diet pills (4% and 2%, respectively); and vomiting (3% and 1%, respectively). Among adults, 38% of women and 24% of men reported that they were trying to lose weight, whereas 28% of each sex reported that they were trying to maintain their weight. CONCLUSIONS: Attempts to lose or maintain weight are very prevalent among both adolescents and adults, especially among females.

Adolescent↗
PubMed1993

The association between weight loss and increased longevity. A review of the evidence.

Six published observational epidemiologic studies have reported evidence of reduced mortality rates in persons who have lost weight. In two studies, the reported protective effects of weight loss on mortality could not be justified by the data. In two other studies, weight loss was associated with both increased and decreased longevity in different subgroups. Only one study provided information on whether the weight loss was voluntary, but this study found similar effects of weight loss regardless of volition. These studies provided only limited information on the magnitude of weight loss associated with changes in longevity and no information on the types of methods used to achieve weight loss. Because of difficulties in studying long-term health outcomes related to obesity treatment, randomized, controlled trials are unlikely to provide a practical study design for this issue. Properly designed observational studies will probably provide the most useful information on the effects of voluntary weight loss on longevity.

Epidemiologic Methods↗
PubMed1993

Weight loss and subsequent death in a cohort of U.S. adults.

OBJECTIVE: Because we previously found that weight loss was associated with increased risk for death in all but very overweight men in a cohort of U.S. adults, we undertook a new analysis to determine whether inadequate control for preexisting illness or cigarette smoking contributed to this association. DESIGN: Cohort study. SETTING: The first National Health and Nutrition Examination Survey (NHANES I, 1971 to 1975) collected information on maximum lifetime weight and measured current weight on a probability sample of U.S. adults. The NHANES I Epidemiologic Follow-up Study determined the vital status of participants through 1987. PARTICIPANTS: Men (n = 2453) and women (n = 2739) who were 45 to 74 years old at the time of the NHANES I examination. RESULTS: The effect of excluding persons who died within the first 5 and first 8 years after baseline was examined to limit the influence of weight loss due to preexisting illness. For women, extension of the exclusionary period weakened the association between weight loss and increased risk for death from noncardiovascular disease. However, excluding death for as much as 8 years after baseline did not affect the strong association between weight loss and increased risk for death from cardiovascular disease among men and women with maximum body mass indexes between 26 and 29 (relative risks of up to 2.1 and 3.6 for men and women, respectively, after excluding deaths in the first 8 years). Results were not substantially altered by limiting the analysis to persons who never smoked. CONCLUSIONS: Preexisting illness may influence the association between weight loss and death principally through deaths from noncardiovascular disease. For some persons, weight loss is associated with an increased risk for death, even after excluding deaths occurring in the first 8 years.

Aged↗