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ABSTRACT: Traditional weight loss (TWL) treatments have been unsuccessful at reducing the prevalence of obesity in the population. Health-care professionals and consumers have criticized TWL treatments as being detrimental to the obese person's health. Consequently, an alternative approach to obesity treatment, the health at any size (H@AS) paradigm, has been proposed. The H@AS paradigm is based on the philosophy that once diet restrictions and barriers to activity have been removed, the individual will develop healthier eating and activity patterns that lead to a naturally healthy body weight. This paper reviews the philosophical foundation and the scientific data that support and oppose the H@AS paradigm and compares it with that of TWL treatments.
Obesity Reviews 03/2001; 2(1):37-45. · 7.04 Impact Factor
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W C Miller
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ABSTRACT: Traditional diet and exercise treatments for obesity have been ineffective in reducing the prevalence of overweight in the population. Treatment outcomes for overweight can be measured in terms of physical parameters (e.g. bodyweight, percentage body fat, body mass index), medical terms (e.g. blood pressure, blood glucose control, blood lipid levels), psychological terms (e.g. eating pathology, self-esteem, mood state) and behavioural terms (e.g. frequency of exercise, eating patterns, self healthcare). Regardless of the specific outcome measures used to define successful treatment, the desired outcome must be maintained for several years to be considered effective. Energy restrictive diets cause significant initial bodyweight loss, but are plagued with high dropout- and relapse-rate. Low-fat diets have met with minimal success for bodyweight control, but nonetheless can significantly lower blood lipid levels. High-protein/low-carbohydrate diets are claimed to be the most effective in reducing bodyweight, but there are no scientific data to support these claims. Persons on these types of diets are also at the greatest risk for metabolic adverse effects. Nondieting approaches and programmes that stress 'health at any size' have not been researched rigorously, but preliminary data show minimal bodyweight loss with significant improvements in psychological state, eating pathology and well-being. Exercise is the only variable that consistently shows effectiveness in physiological, medical, psychological and behavioural outcomes. A treatment programme that has the greatest potential for success, regardless of outcome measure, is a programme that consists of 4 key components. These components are: (i) pre-evaluation, where historical information is gathered and used to set programme goals, objectives and outcome measures; (ii) exercise, wherein enjoyable exercise is encouraged for health, bodyweight control and well being; (iii) a behavioural plan, which is based on patterns of eating and activity that will lead to the desired outcome measures; and (iv) a maintenance plan, that helps the individual develop skills for maintaining newly developed behaviours.
Sports Medicine 02/2001; 31(10):717-24. · 5.16 Impact Factor
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W C Miller
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ABSTRACT: Health care professionals have used restrictive dieting and exercise intervention strategies in an effort to combat the rising prevalence of obesity in affluent countries. In spite of these efforts, the prevalence of obesity continues to rise. This apparent ineffectiveness of diet and exercise programming to reduce obesity has caused many health care providers, obesity researchers, and lay persons to challenge the further use of diet and exercise for the sole purpose of reducing body weight in the obese. The purposes of this paper were to examine the history and effectiveness of diet and exercise in obesity therapy and to determine the best future approach for health promotion in the obese population. A brief survey of the most popular dieting techniques used over the past 40 yr shows that most techniques cycle in and out of popularity and that many of these techniques may be hazardous to health. Data from the scientific community indicate that a 15-wk diet or diet plus exercise program produces a weight loss of about 11 kg with a 60-80% maintenance after 1 yr. Although long-term follow-up data are meager, the data that do exist suggest almost complete relapse after 3-5 yr. The paucity of data provided by the weight-loss industry has been inadequate or inconclusive. Those who challenge the use of diet and exercise solely for weight control purposes base their position on the absence of weight-loss effectiveness data and on the presence of harmful effects of restrictive dieting. Any intervention strategy for the obese should be one that would promote the development of a healthy lifestyle. The outcome parameters used to evaluate the success of such an intervention should be specific to chronic disease risk and symptomatologies and not limited to medically ambiguous variables like body weight or body composition.
Medicine & Science in Sports & Exercise 09/1999; 31(8):1129-34. · 4.43 Impact Factor
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ABSTRACT: The purpose of this research was to derive and compare regression equations for predicting residual volume (RV) in overweight and normal weight adults.
RV was determined on land, in 311 men and women, following an overnight fast, using the nitrogen-dilution technique. Subjects were then weighed underwater at RV; 5-10 underwater weights were recorded; and the heaviest 3 measurements were averaged as the underwater weight. Percent body fat was calculated using the Siri equation. Group analyses were performed on overweight men (N = 59, body fat > 25%) and women (N = 126, body fat > 30%) compared with normal weight men (N = 68, body fat < or = 25%) and women (N = 58, body fat < or = 30%). A stepwise regression was performed for each group using the Systat Statistical Package (Evanston, IL).
When RV was regressed on sex, age (yr), body weight (kg), and height (cm), sex was not found to be a significant predictor variable for RV. Subsequent regressions revealed that prediction equations for the overweight (RV = 0.0277 AGE + 0.0048 WT + 0.0138 HT - 2.3967, F = 44.0, P < 0.0000, SEE = 0.403) were different from those generated for normal weight men and women (RV = 0.0275 AGE + 0.0189 HT - 2.6139, F = 58.6, P < 0.0000, SEE = 0.405). Similar equations were obtained when a cross validation was performed on a separate sample of normal weight (N = 31) and overweight (N = 46) men and women.
These data suggest that prediction equations for RV are separate and distinct for the overweight and normal weight populations.
Medicine & Science in Sports & Exercise 02/1998; 30(2):322-7. · 4.43 Impact Factor
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ABSTRACT: The therapeutic effectiveness of diet, exercise, and diet plus exercise for weight loss in obesity was determined.
All human research reported in English, published in peer-reviewed scientific journals within the past 25 y was reviewed.
Acceptance criteria (n = 493 from > 700 studies) were that a therapeutic intervention of diet, exercise or diet plus exercise was employed, specifically for weight reduction in obese adult humans and that weight change was reported numerically. Only aerobic exercise studies were included, while drug, hormone and surgical treatments were excluded.
All data were extracted by the same investigator from the original research report. Except for gender and program type, all extracted data were numerical.
ANOVA, with a Newman-Keuls post hoc test, was used to determine differences among programs (P < 0.05). One analysis was performed on the group mean data and one based on effect sizes. Analyses were repeated using initial body weight, initial percent body fat and program length, as covariates.
Primarily, subjects aged 40 y have been studied (39.5 +/- 0.4 y, mean +/- s.e.m.) who are only moderately obese (92.7 +/- 0.9 kg, 33.2 +/- 0.5 body mass index (BMI), 33.4 +/- 0.7% body fat); for short durations (15.6 +/- 0.6 weeks). Exercise studies were of a shorter duration, used younger subjects who weighed less, had lower BMI and percentage body fat values, than diet or diet plus exercise studies. Despite these differences, weight lost through diet, exercise and diet plus exercise was 10.7 +/- 0.5, 2.9 +/- 0.4* and 11.0 +/- 0.6 kg, respectively. However, at one-year follow-up, diet plus exercise tended to be the superior program. Effect size and covariate analyses revealed similar program differences.
Weight loss research over the past 25 y has been very narrowly focused on a middle age population that is only moderately obese, while the interventions lasted for only short periods of time. The data shows, however, that a 15-week diet or diet plus exercise program, produces a weight loss of about 11 kg, with a 6.6 +/- 0.5 and 8.6 +/- 0.8 kg maintained loss after one year, respectively.
International Journal of Obesity 10/1997; 21(10):941-7. · 4.69 Impact Factor
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ABSTRACT: This study was conducted to determine the relationships among the specific components of dietary fat and carbohydrate and body fatness in lean and obese adults.
Body composition determination was performed on each subject by hydrostatic weighing at residual volume. Subsequently, the individual components of dietary fat and carbohydrate were examined relative to body fatness using a 3-day food diary and a food frequency questionnaire.
Subjects were 23 lean (11.1 +/- 2.9% body fat) men, 23 obese (29.2 +/- 3.8% body fat) men, 17 lean (16.7 +/- 3.3% body fat) women, and 15 obese (42.7 +/- 3.9% body fat) women who volunteered for free diet and body composition analyses. Inclusion criteria were 15% body fat for lean men, 25% for obese men, 20% for lean women, and 35% for obese women.
Group comparisons for dietary variables were made with a multivariate analysis of variance.
No differences were found between lean and obese subjects for energy intake or total sugar intake, but obese subjects derived a greater portion of their energy from fat (33.1 +/- 2.6% and 36.3 +/- 2.3% for obese men and women, respectively, vs 29.1 +/- 1.3% and 29.6 +/- 2.0%, lean men and women, respectively). Percent of fat intake for saturated, monounsaturated, and polyunsaturated fats was not different among groups. Obese subjects derived a greater percentage of their sugar intake from added sugars than lean subjects (38.0 +/- 3.5% vs 25.2 +/- 2.0%, respectively, for men; 47.9 +/- 8.0% vs 31.4 +/- 3.4%, respectively, for women). Dietary fiber was lower for obese men (20.9 +/- 1.8 g) and women (15.7 +/- 1.1 g) than for lean men (27.0 +/- 1.8 g) and women (22.7 +/- 2.1 g).
Obesity is maintained primarily by a diet that is high in fat and added sugar and relatively low in fiber. Alterations in diet composition rather than energy intake may be a weight control strategy for overweight adults.
Journal of the American Dietetic Association 07/1994; 94(6):612-5. · 3.59 Impact Factor
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ABSTRACT: There is little evidence concerning the effectiveness of self-help materials for weight control. The purpose of this research was to evaluate a self-help weight-loss program. Obese (body fat > or = 25.0%, range = 25.0-48.6%, mean +/- SEM = 36.5 +/- 1.3%) men (n = 14) and women (n = 21) were given a workbook detailing a behavior modification approach to weight loss that emphasizes self-monitoring of diet and exercise behaviors, and then sent home for 6 months to learn how to lose weight on their own. A group of 9 controls (CONT) who did not get a workbook were used for comparison. ANOVA showed that the experimental group (EXP) lost 8.1 +/- 0.9 (mean +/- SEM) kg body weight, 6.4 +/- 0.8 kg fat, and 3.9 +/- 0.6% body fat; all significant over time (p < 0.001) and different from the CONT (p < 0.0001) who showed no change in these variables. The EXP also reduced their fat intake (% of joules) from 36.1 +/- 1.0% to 27.9 +/- 1.3% (p < 0.0001), increased their carbohydrate intake from 45.7 +/- 1.2% to 50.0 +/- 1.7% (p < 0.007) and their protein intake from 16.3 +/- 0.05% to 20.7 +/- 0.7% (0 < 0.03), all of which were significantly different (p < 0.03) than the CONT who did not change. Dietary fiber increased in the EXP from 19.8 +/- 1.4 to 27.3 +/- 2.2 g/d (p < 0.001) even with a significant reduction in energy intake (11.3 +/- 0.6 vs. 8.9 +/- 0.5 Mj/d; p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
International Journal of Sports Medicine 11/1993; 14(7):401-5. · 2.43 Impact Factor
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ABSTRACT: This research derived regression equations for predicting maximal heart rate (MHR) and examined the relationship between relative oxygen consumption (VO2) and heart rate (HR) in obese (N = 86, body fat > 30%, hydrostatic weighing) compared with normal-weight (N = 51, body fat < or = 30%) adults. Simultaneous measurements of HR and VO2 were recorded at rest and every minute during a maximal graded exercise test. When MHR was regressed on age, two distinct equations for the obese and normalweights were generated. The relationship between %MHR and %max VO2 was similar between groups (r = 0.83, obese; r = 0.87 normalweights). Likewise, when %max VO2 was regressed on %max heart rate range similar equations were derived fro the obese (r = 0.81) and normalweights (r = 0.84). Correlation between Karvonen's predicted HR at a submaximal VO2 and the true HR at that VO2 was 0.88, regardless of adiposity. These data indicate that when predicting MHR in normalweights the equation 220-Age can be used, but for obese individuals the equation 200-0.5 x Age is more accurate; each having 12 as a standard error of estimate. Once MHR is determined, either the straight percentage technique or Karvonen's method would be appropriate for prescribing exercise intensity for both populations.
Medicine & Science in Sports & Exercise 10/1993; 25(9):1077-81. · 4.43 Impact Factor
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Journal of the American Dietetic Association 09/1991; 91(8):973-5. · 3.59 Impact Factor
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W C Miller
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ABSTRACT: The association of obesity with increased risks for developing hypertension, diabetes, cardiovascular disease, and cancer has made it a complex health problem. Exacerbating the problem is the realization that there are multiple factors, both physiological and psychological, that interact to induce obesity, as well as a myriad of components that may be useful in the curtailment of obesity. The aim of this symposium is to provide a wider understanding of the elements behind the development and reduction of obesity.
Medicine & Science in Sports & Exercise 04/1991; 23(3):273-4. · 4.43 Impact Factor
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W C Miller
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ABSTRACT: There are dietary factors besides the total energy value of food that can affect adiposity by disrupting the balance between energy intake and expenditure. The purpose of this paper was to examine how perturbation of these dietary factors that control energy balance affects adiposity. There is a substantial amount of evidence suggesting that obesity is not associated with overeating, but with a high dietary fat-to-carbohydrate intake ratio. Physiological adaptations to energy-reduced dieting facilitate both weight regain and make it more difficult to lose weight during subsequent dieting attempts. Since obesity may be better characterized by diet composition than by energy intake, successful weight-loss programs should include diet compositional changes in their regimes.
Medicine & Science in Sports & Exercise 04/1991; 23(3):280-4. · 4.43 Impact Factor
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ABSTRACT: This study examined the relationships among body fat, diet composition, energy intake, and exercise in adults. Male (n = 107) and female (n = 109) adults aged 18-71 y (36.6 +/- 1.0 y, means +/- SEM) were hydrostatically weighed to determine body fat (5.7-49.0% of total weight). Diet and exercise behaviors were determined by use of a questionnaire. As body fat increased, percent of energy intake derived from fat increased (p less than 0.001) whereas the percent from carbohydrate decreased (p less than 0.001). There was no relationship between energy intake and adiposity although leanness and exercise were related (p less than 0.001). When subgroups of lean and obese subjects were compared, the lean subjects derived approximately 29% of their energy from fat and 53% from carbohydrate vs 35% and 46%, respectively, for the obese subjects. No differences were found between groups for energy intake but the lean individuals exercised more often than did the obese individuals. These data suggest that diet composition may play as important a role in fat deposition as do energy intake and lack of exercise.
American Journal of Clinical Nutrition 10/1990; 52(3):426-30. · 6.67 Impact Factor
