Search

Background: Each year millions of Americans enroll in commercial and self-help weight loss programs. Health care providers and their obese patients know little about these programs because of the absence of systematic reviews., Purpose: To describe the components, costs, and efficacy of the major commercial and organized self-help weight loss programs in the United States that provide structured in-person or online counseling., Data Sources: Review of company Web sites, telephone discussion with company representatives, and search of the MEDLINE database., Study Selection: Randomized trials at least 12 weeks in duration that enrolled only adults and assessed interventions as they are usually provided to the public, or case series that met these criteria, stated the number of enrollees, and included a follow-up evaluation that lasted 1 year or longer., Data Extraction: Data were extracted on study design, attrition, weight loss, duration of follow-up, and maintenance of weight loss., Data Synthesis: We found studies of eDiets.com, Health Management Resources, Take Off Pounds Sensibly, OPTIFAST, and Weight Watchers. Of 3 randomized, controlled trials of Weight Watchers, the largest reported a loss of 3.2% of initial weight at 2 years. One randomized trial and several case series of medically supervised very-low-calorie diet programs found that patients who completed treatment lost approximately 15% to 25% of initial weight. These programs were associated with high costs, high attrition rates, and a high probability of regaining 50% or more of lost weight in 1 to 2 years. Commercial interventions available over the Internet and organized self-help programs produced minimal weight loss., Limitations: Because many studies did not control for high attrition rates, the reported results are probably a best-case scenario., Conclusions: With the exception of 1 trial of Weight Watchers, the evidence to support the use of the major commercial and self-help weight loss programs is suboptimal. Controlled trials are needed to assess the efficacy and cost-effectiveness of these interventions.

In response to an accelerating obesity pandemic, competing weight-loss diets have propagated; those touting carbohydrate restriction are currently most in vogue. Evidence that sustainable weight loss is enhanced by means other than caloric restriction, however, is lacking. Whereas short-term weight loss is consistently achieved by any dietary approach to the restriction of choice and thereby calories, lasting weight control is not. Competing dietary claims imply that fundamental knowledge of dietary pattern and human health is lacking; an extensive literature belies this notion. The same dietary and lifestyle pattern conducive to health promotion is consistently associated with weight control. A bird's eye view of the literature on diet and weight reveals a forest otherwise difficult to discern through the trees. Competing diet claims are diverting attention and resources from what is actually and urgently needed: a dedicated and concerted effort to make the basic dietary pattern known to support both health and weight control more accessible to all.

Weight-loss diets advertised in mainstream non-scientific publications and targeting the adult female public were evaluated in relation to total energy value, macronutrients, calcium, iron, vitamins A and E, and cholesterol content, as well as the presence of information regarding the duration of diets, fluid intake, physical activity, and maintenance diets. Two publications were selected, considering periodicity, circulation, readership, and years in publication. The Virtual Nutri software was used to evaluate the nutrients of 112 diets. Micronutrient content was compared to the Dietary Reference Intakes. All diets were inadequate in at least one of the evaluated items. Less than 25.0% of the diets presented adequate macronutrient distribution. Calcium, iron, and vitamin E were also predominantly inadequate (85.7, 97.3, and 91.9%, respectively). Non-scientific publications should not be allowed to advertise weight-loss diets. In addition, their chemical composition is inadequate and they are not accompanied by important instructions for such therapy.

Short-term studies indicate that intentional weight loss (IWL) among obese persons significantly improves health variables that are often precursors or markers of chronic diseases (e.g. heart diseases, type-2 diabetes). Hence, it is logical to assume that IWL among obese persons would lead to increased longevity. On the whole, epidemiological studies, including recent ones that use conservative analytic approaches such as distinguishing between apparently IWL and unintentional weight loss (UWL), adjusting for potential confounders and excluding apparently unhealthy subjects, indicate that apparently IWL appears to neither increase nor decrease mortality rate. However, it is important to note that none of the existing studies were designed specifically to test the hypothesis that IWL reduces mortality rate, and given methodological problems, these studies do not provide a satisfactory way to address the body mass index (BMI)-mortality question. Several controlled clinical trials suggest that IWL may reduce mortality rate. However, even in these studies, it is important to acknowledge that subjects are randomized to conditions that produce more or less weight loss and not to distinct levels of weight loss per se. Nevertheless, while we await additional data from better designed studies, given our incomplete knowledge, we conclude that it seems more likely than not that IWL achieved by medically recommended methods does not increase and probably decreases mortality rate.

Unlabelled: We assessed the effect of a weight management programme on body weight, body mass index (BMI), and fitness in obese children and adolescents. The study was designed as a longitudinal, non-randomised, clinical experience of a 3 and 6 month combined dietary-behavioural-exercise intervention. A total of 177 obese children (age 6-16 years) participated in the 3 month programme, of whom 65 completed the 6 month intervention. A group of 25 age- and maturity-matched obese children who did not participate in the structured programme served as controls. Body weight, BMI, and fitness were evaluated at baseline, and after the 3 and 6 months intervention. Body weight and BMI were significantly reduced ( P<0.05), and endurance time significantly increased ( P<0.0005) following the 3 months intervention. Obese children who continued the programme for 6 months maintained the decrease in BMI and further improved endurance time. In contrast, obese children who did not participate in the structured programme gained weight, increased their BMI, and improved fitness less significantly. Gender, pubertal status, and the degree of obesity had no influence on BMI changes. Children without parental overweight had significantly greater decreases in BMI compared to children of obese parents., Conclusion: a combined, structured multidisciplinary intervention for childhood obesity results in decreased body weight, decreased body mass index and improved fitness.

The objective was to evaluate the efficacy of worksite weight reduction programs at high-stress worksites. We employed a longitudinal study based on two meal replacements daily with subjects choosing a third 'sensible' meal. The subjects were 492 healthy, overweight men and women working in high-stress occupations (police, hospital health professionals, flight crew members, firefighters). The mean group ages ranged from 32.17 +/- 5.70 to 44.50 +/- 16.40 years; the mean group body mass indexes (BMIs) ranged from 27.40 +/- 2.54 to 32.90 +/- 3.39 kg/m(2). The completion rate for the 12 weeks was 79.8%. Reductions in mean weight and mean BMI were greater than in medically supervised clinical trials with non-worksite adults. Firefighters lost the most weight and medical personnel the least. Follow-up found considerable retention of weight loss. Men lost significantly more weight than women (p < 0.006). We conclude that employees in some high-stress settings may participate productively in worksite weight reduction and maintenance programs that use meal replacements.

High-protein diets have recently been proposed as a "new" strategy for successful weight loss. However, variations of these diets have been popular since the 1960s. High-protein diets typically offer wide latitude in protein food choices, are restrictive in other food choices (mainly carbohydrates), and provide structured eating plans. They also often promote misconceptions about carbohydrates, insulin resistance, ketosis, and fat burning as mechanisms of action for weight loss. Although these diets may not be harmful for most healthy people for a short period of time, there are no long-term scientific studies to support their overall efficacy and safety. These diets are generally associated with higher intakes of total fat, saturated fat, and cholesterol because the protein is provided mainly by animal sources. In high-protein diets, weight loss is initially high due to fluid loss related to reduced carbohydrate intake, overall caloric restriction, and ketosis-induced appetite suppression. Beneficial effects on blood lipids and insulin resistance are due to the weight loss, not to the change in caloric composition. Promoters of high-protein diets promise successful results by encouraging high-protein food choices that are usually restricted in other diets, thus providing initial palatability, an attractive alternative to other weight-reduction diets that have not worked for a variety of reasons for most individuals. High-protein diets are not recommended because they restrict healthful foods that provide essential nutrients and do not provide the variety of foods needed to adequately meet nutritional needs. Individuals who follow these diets are therefore at risk for compromised vitamin and mineral intake, as well as potential cardiac, renal, bone, and liver abnormalities overall.

Diet prescription is a fundamental first-line element in the management of patients with dyslipidemia. Weight loss should be a primary goal for all overweight patients. A 5 to 10% weight loss is often sufficient to obtain a significant improvement in lipid levels. Dietary fat should not provide more than 30% of total calorie intake. Saturated fatty acids should not exceed 7% and polyunsaturated fatty acids should also be limited to 7 to 10%. For monounsaturated fatty acids the dietary allowance can be a bit wider, up to 15% of total calorie intake. Carbohydrates, particularly complex carbohydrates, should replace the fat calories. Dietary fiber (more than 20g/d) as well as soy protein or phyto-sterols can be helpful in reducing LDL-cholesterol by about 10%. Consumption of fruits and vegetables should also be encouraged because they provide antioxidants that have effects on other cardiovascular risk factors. Long-term education is needed to encourage the patient to comply with this type of diet. Psycho-behavioral strategies can be useful here.

One of the first steps in a clinical approach to any obese subject should be focused on the reduction and/or normalization of any potential or existing metabolic abnormality. Overeating and/or unbalanced food intake remains the major element in the origin and maintenance of obesity. The reduction of energy intake is the basis of successful weight loss. In obese subjects there are huge amounts of energy stored, mainly in the adipose tissue, which are mobilized according to the size and duration of an energy deficit. Considerable studies have been devoted to finding the optimal dietary approach that would promote rapid weight loss while maximizing the depletion of adipose tissue and conserving body protein. During fasting adipose tissue lipolysis rate increases and liberated unesterified fatty acids are oxidized in muscle and liver. The liver produces ketones which are oxidized in muscle and brain. The energy need of the brain is not sufficiently covered by ketone oxidation, therefore additional glucose must be provided. The liver produces glucose by gluconeogenesis using amino acids from muscle protein. Because of limited protein sources, protein must be given during energy restricted diet. Besides protein also vitamins, minerals, trace elements, fiber, and linoleic acid must be substituted during fasting and during treatment with very low calorie diets. Meal replacements are helpful to fulfil all the requirements. There is consensus that the first step in dietary treatment is an energy restricted diet with a calorie deficit of at least 600 Kcal/day, but more than 800 Kcal/day must be provided, with all essential nutrients. Observing the regulations, weight reduction with appropriate diet plans improves metabolic disturbances.

Obesity is a serious problem in the United States. More than 50% of adult Americans have body mass indices equal to or greater than 25--the new criteria for being overweight. US Government health organizations have recently issued clinical guidelines for the identification, evaluation, and treatment of obesity, and criteria for evaluating weight loss programs. Despite all this, overweight individuals often turn for guidance to weight loss books and programs promoted in the popular press rather than healthcare professionals. A review of some of the most popular diet programs reveals that they fall along a continuum from "anticarbohydrate" to "anti-fat." Several of these diets are discussed and evaluated based on the criteria proposed by obesity experts.

Childhood obesity is a chronic disease that is associated with significant co-morbidity. Successful treatment and prevention of childhood obesity requires a multidisciplinary approach, including diet, nutrition education, behavior modification, and exercise. We studied 87 children (39 males, 48 females; aged 7-17 years) enrolled in a one-year multidisciplinary weight reduction program. Subjects were placed on a very low calorie/high protein diet, a moderate-intensity progressive exercise program, and behavior modification sessions for 10 weeks. Measures were taken at baseline 10 weeks, and 1 year. Significant anthropometric changes in weight, percent of ideal body weight, and percent body-fat were observed in all patients. We conclude that a multidisciplinary weight reduction program including diet, behavior modification, and exercise is an effective instrument to achieve weight loss in obese children and adolescents.

One approach for investigating biological aging is to compare control-fed animals with others restricted in calorie intake by 20% or more. Caloric restriction (CR) is the only intervention shown to extend the maximum lifespan of several invertebrates and vertebrates including spiders, fish, rats and mice. The capacity of CR to retard aging in nonhuman primates is now being explored. The rodent studies show that CR opposes the development of many age-associated pathophysiological changes, including changes to the brain and changes in learning and behavior. One goal of studying CR in rodent is to determine the mechanisms by which it retards aging to design interventions that duplicate those effects. The methods that we use for conducting CR studies on mice and rhesus monkeys are described. We employ procedures designed to achieve a high degree of caloric control for all animals in the study. As used in our studies, this control includes the following features: 1) animals are individually housed, and 2) all individuals in the control group eat the same number of calories (i.e., they are not fed ad lib). Although this method results in strict caloric control for all animals, there seems to be considerable procedural flexibility for the successful conduct of CR studies.

The American Heart Association recently upgraded obesity to be a significant risk factor for heart disease and federal health officials issued new clinical guidelines for managing this risk in adults. Find out how one major health plan has incorporated medical weight management into all of its chronic DM programs.

Several canine weight loss protocols were evaluated to determine their relative safety and efficacy. Dogs were fed 100%, 75%, 60%, or 50% of maintenance energy requirements (MERs) using the dogs' target body weights. No indications of adverse health effects were observed with any weight loss protocol. Triiodothyronine (T3) levels and apparent MERs decreased in dogs restricted to 50% to 60% of their MERs. The rate of weight loss was correlated linearly with degree of calorie restriction, although there was considerable individual variation. Percent overweight by the end of the test was not different between protocol groups for dogs fed 50%, 60%, or 75% of MERs. Therefore, any of the protocols tested in this study may be used in the management of overweight dogs; however, individual responses will be expected to vary, and severe calorie restriction may predispose dogs to weight rebound.

This study investigated changes in body composition, resting energy expenditure (REE), appetite, and mood in 128 obese women who were randomly assigned to 1 of 4 treatment conditions: diet alone, diet plus aerobic training, diet plus strength training, or diet combined with aerobic and strength training (i.e., combined training). All women received the same 48-week group behavioral program and were prescribed the same diet. Exercising participants were provided 3 supervised exercise sessions per week for the first 28 weeks and 2 sessions weekly thereafter. Participants across the 4 conditions achieved a mean weight loss of 16.5 +/- 6.8 kg at Week 24, which decreased to 15.1 +/- 8.4 kg at Week 48. There were no significant differences among conditions at any time in changes in weight or body composition. Women who received aerobic training displayed significantly smaller reductions in REE at Week 24 than did those who received strength training. There were no other significant differences among conditions at any time on this variable or in changes in appetite and mood.

Objective: To compare the effects of two weight loss interventions, diet or exercise, on changes in bone, fat and lean tissue., Design: Prospective, long term, worksite, randomised and controlled weight-loss study using a low fat diet ad libitum or moderate aerobic exercise., Subjects: 66 overweight men (mean age 43.4 +/- 5.7 y, BMI 29.0 +/- 2.6 kg/m2)., Measurements: Body weight, lean mass, fat mass, bone mass (BMC), bone mineral density (BMD) by dual-energy X-ray absorptiometry., Results: Dieters lost 1.4% BMC (1.5% BMD) with 6.4 kg weight loss; there was no significant change in BMC (or in BMD) in exercisers (2.6 kg weight loss) or in control subjects (no weight change). Changes in BMC were correlated with fat loss with both interventions: 11.7 g BMC/kg fat loss in dieters, 11.4 g BMC change/kg fat loss in exercisers., Conclusion: BMC loss with diet-induced weight loss reflects loss of weight and especially loss of body fat. Further study to determine whether similar BMC loss will accompany equivalent weight loss induced by exercise is needed.

Objective: The first objective was to determine the associated sensitivity (true positives) and specificity (false positives) associated with the use of waist circumference (WC) to predict specific visceral adipose tissue (VAT) levels. Because WC is a strong correlate of VAT, and, a WC of 100 cm and a VAT area of 130 cm2 (L4-L5) have been suggested as thresholds for increased disturbances in insulin-glucose homeostasis and lipid metabolism, we assessed the sensitivity and specificity when using a WC of 100 cm to identify a VAT of 130 cm2 or greater. A second objective was to evaluate the effects of diet and exercise induced weight loss on VAT and WC to establish the utility of using WC to follow reductions in VAT., Research Design and Methods: The sensitivity between WC and VAT was assessed using 50 male (BMI: 30.9 +/- 4.7, age: 41.0 +/- 11.2 y) and 49 female (BMI: 33.3 +/- 5.0, age: 36.9 +/- 7.4 y) subjects. The effects of weight loss on WC and VAT were evaluated in a subgroup of 20 male and 38 female subjects. VAT was measured by magnetic resonance imaging., Results: The sensitivity associated with the prediction of a VAT of 130 cm2 or greater using a WC of 100 cm was high (83%), however, so too was the incidence of false positives (38%). Significant (p < 0.01) correlations were obtained between concurrent reductions in VAT and WC for both the male (r = 0.69) and female (r = 0.47) groups. For the two groups combined, regression analysis indicated that a 1 cm reduction in WC was associated with a 4% reduction in VAT mass (p < 0.01)., Conclusions: The misclassification of individuals with VAT accumulation above 130 cm2 suggest that WC alone lacks the sensitivity required to identify specific VAT values. The diet and exercise induced reductions in visceral adiposity are positively related to corresponding reductions in WC for both genders is a positive result, and demonstrates the potential utility of using WC to follow changes in the AT depot that conveys the greatest health risk.

A review of the literature and research on food restriction indicates that inhibiting food intake has consequences that may not have been anticipated by those attempting such restriction. Starvation and self-imposed dieting appear to result in eating binges once food is available and in psychological manifestations such as preoccupation with food and eating, increased emotional responsiveness and dysphoria, and distractibility. Caution is thus advisable in counseling clients to restrict their eating and diet to lose weight, as the negative sequelae may outweigh the benefits of restraining one's eating. Instead, healthful, balanced eating without specific food restrictions should be recommended as a long-term strategy to avoid the perils of restrictive dieting.

Thirteen overweight domestic short-haired cats were fed a commercial low calorie diet for 18 weeks at an energy intake to lose weight; they lost an average of 18.1 per cent of their starting weight. An evaluation of their body composition by dual energy x-ray absorptiometry before and after the study suggested that most of the weight lost was composed of fat. The cats' lean bodyweight did not change significantly, but increased as a proportion of total bodyweight.

Objective: To examine the association of energy and % energy from fat with body mass index (BMI) and determine if self-reported dieting altered observed associations., Design: Dietary intake data based on dietary recalls from four nonconsecutive days over a 1 year period were examined relative to BMI. The relation between energy intake and % energy from fat and BMI was examined by linear regression analysis., Subjects: The sample included 1854 free-living women aged 19-50 years who participated in the 1985-6 Continuing Surveys of Food Intakes by Individuals conducted by the United States Department of Agriculture., Results: Reported energy intake was inversely associated with BMI (regression coefficient (beta) = -0.001 24, standard error (s.e.) = 0.000 31). Controlling for low energy dieting alone reduced the inverse energy intake-BMI association by approximately 20% (beta = -0.001 00, s.e. = 0.000 31), compared to reductions of 16%, 13% and 10%, respectively, when health status, age and education were added individually to the energy intake-BMI linear regression. Physical activity, smoking status, % energy from fat and report of low fat dieting did not reduce the energy intake-BMI association. Controlling for nondietary factors related to BMI and potentially influencing energy intake reduced the inverse energy intake-BMI association by approximately 22% (beta = -0.000 97, s.e. = 0.00025). Further adjustment for low energy dieting on day 1 reduced the inverse energy intake-BMI association by 40% (beta = -0.000 74, s.e. = 0.000 26), suggesting that intermittent energy restriction was a significant factor in the reduced energy intake reported among overweight women. Percent energy from fat was not associated with BMI (beta = 0.049, s.e. = 0.025, P = 0.055). Exclusion of 37 women reporting poor health status further attenuated the inverse association between energy intake and BMI (beta = -0.000 64), s.e. = 0.000 26), while it strengthened the previously non-significant positive association between % energy from fat and BMI (beta = 0.062; s.e. = 0.024)., Conclusion: Intermittent energy restriction appeared to be a significant factor in the reduced energy intake reported among overweight women in this sample. Adequate assessment of energy expenditure is required to correctly interpret the association of energy intake to body weight.

Objective: To determine the safety of very low calorie diets (VLCD) in regard to their effects on cardiac function., Design: EKG changes were analyzed for 126 women on a VLCD of 3349 kJ/d (800 kcal/d). EKGs were done when the diet was begun, after 3 months of dieting, and at a 6 month follow up after being off the diet for 3 months., Setting: Subjects were solicited through advertisements and charged $1,000 for participating after being screened for age, weight, and health status., Main Outcome Measures: EKG QTc intervals, PR interval, QRS interval, ST-T wave changes, and heart rate., Results: Over one-fourth (27.0%) of subjects had normal EKGs at all three time points studied. Sinus bradycardia was the most common abnormality, observed in 60 subjects (47.6%) on at least one of the three EKGs. Fifty-eight (46%) patients had EKGs with ST-T wave abnormalities observed on at least one of the EKGs. Eight subjects (6.4%) had prolonged QTc (more than one standard deviation beyond the average for women) intervals on at least one EKG. None of these eight persons had significant untoward medical consequences., Conclusion: A VLCD diet of 3349 kJ/d (800 kcal/d) for up to 3 months is not associated with significant electrocardiographic abnormalities or clinical cardiac complications, provided the patients have low cardiovascular risk at baseline.

Objective: To determine whether ketogenic weight reducing diets have adverse effects on cognitive performance., Subjects: 21 overweight women (mean BMI = 41 kg/m2)., Design: Randomized double-blinded study., Method: Subjects were randomized to ketogenic or nonketogenic liquid formula very low energy diets, that were comparable in energy and in protein content. Subjects remained on the diet for 28 days and were reevaluated periodically with brief measures of cognitive performance assessing attention and mental flexibility., Results: Weight losses were comparable on the two diets (Mean = 8.1 kg). Performance on attention tasks did not differ as a function of the diet. However, performance on the trail making task, a neuropsychological test that requires higher order mental processing and flexibility, was adversely affected by the ketogenic diet. The worsening in performance was observed primarily between baseline and week one of the ketogenic diet., Conclusions: Further research is needed to confirm this finding and to determine whether ketogenic diets negatively affect other complex mental tasks, such as problem solving.

Objective: To assess a wide range of health-related behaviours, beliefs and knowledge in educated young adults., Design: A standardized questionnaire was developed, translated, and administered in university classes., Subjects: 16,486 university students in 21 European countries., Dependent Variables: Reported and self-perceived body size, eating practices and weight concerns., Results: Body Mass Index (BMI; weight (kg)/height (m)2) was slightly different between countries, and rather low overall (20.5 in women and 22.0 in men). These low values can be attributed to the young age of respondents (21.4 years) and to their presumably high socio-economic status. Very few were overweight (8%) and less than 1% were obese. In spite of the low BMI, many perceived themselves as overweight, especially among women. Trying to lose weight (44% of women, 17% of men) and dieting (14% in women and 3% in men) were not uncommon, although large differences existed between countries. Dieting affected snack and meal patterns: dieters reported fewer snacks and female dieters also reported fewer meals than non-dieters. Breakfast was skipped by almost twice as many dieters as non-dieters. Some evidence of anorexia nervosa (dieting in very underweight individuals) appeared., Conclusion: The data suggest excessive responses to weight loss pressures and imperfect translation of nutritional advice into behaviours.

Research on exercise in the treatment of childhood obesity is reviewed. The role of activity or sedentary behaviors in the development of obesity is discussed, with a conceptual model for understanding choice of being sedentary or active presented. Research that assesses the effects of exercise alone and diet plus exercise on child weight control are reviewed, as well as new research on modifying access to sedentary behaviors. Treatment research suggests exercise alone is not sufficient, with the combination of diet plus exercise more effective for long-term than short-term changes. Finally, suggestions for new research are presented.

Prevention of obesity and increase in longevity in obesity-prone rodents can be achieved by long-term moderate dietary restriction. In order to examine the likelihood that caloric restriction could have similar salutary effects in humans, rhesus monkeys, after reaching mature adult stature, were placed on a protocol to clamp or stabilize body weight by weekly caloric adjustment. Furtherweight gain was prevented by this caloric titration procedure, and thus middle-age onset obesity, which is very common in this species, was prevented. The present study analyzed daily food intake for six weight-clamped monkeys and six ad libitum fed age-matched animals over a 3-year period, ages 18.5 to 21.5 years. After approximately 9 years of caloric restriction the daily calorie load to maintain stable adult body weight proved to be 40% less than the amount ingested by ad libitum fed animals. Calories per kg body weight did not differ significantly between the groups although the ad libitum fed animals were significantly fatter than the weight-clamped group. Prevention of obesity using this weight clamp protocol has also maintained lower insulin levels and higher glucose tolerance in the restricted animals.

A very-low-calorie conventional Japanese diet of 370 kcal/day has been shown to be useful for weight reduction and its long-term maintenance. Sources of the diet were mainly from chicken fillet, egg white, fish white-meat, mushroom, seaweed and low- or non-calorie fiber-rich vegetable, and contained 4.4g fat, 38.1g protein, 45.2g carbohydrate and essential minerals and vitamins. However, metabolic and neural implications of a commercial very-low-calorie liquid formula diet have rarely been investigated from the view point of food intake and appetite regulation. Animal studies have demonstrated the rationale for efficacy of the very-low calorie conventional Japanese diet as follows: (1) Increased hypothalamic histamine suppressed food intake through H1-receptors in the ventromedial hypothalamus (VMH) and paraventricular nucleus, the satiety centers. (2) Low energy intake enhanced satiety and decreased food intake through histaminergic activation of VMH neurons. (3) Mastication activated afferent signal transmission from proprioceptors in the oral cavity to the mesencephalic trigeminal nucleus(Me5). Histaminergic systems in the hypothalamus were activated by mastication and low energy supply, which was accompanied by satiation through the action of histamine in the VMH. Usefulness of the very-low-calorie conventional Japanese diet derives from utilization of conventional Japanese food stuffs as a fiber rich, low energy food source, and from enhancement of satiation by increased mastication required of the diet. The properties of the diet seemed to effect a closed positive feedback loop between histaminergic activation in hypothalamic satiety centers and behavioral changes to enhance satiation and cause feeding suppression.

Overweight and obesity have an underestimated impact on public health and therefore on national economic costs. The rising prevalence of overweight and obesity is inextricably linked to the increase in the average BMI and its population distribution. English activity patterns have probably fallen over 20 years by an average of 800 kcal/day; the remarkable changes in eating patterns reflect the pervasive physiological suppression of intake by about 750 kcal/d. The resulting small positive energy balance explains the secular increase in average adult weight. Similar changes and discrepancies occur with aging. Together these changes can explain the accelerating skewness of BMI distribution and particular propensity of women to obesity. The genetically susceptible probably dominate the upper BMI range and seem to reflect subtle discrepancies in energy balance in an inactive society on a high fat diet. Maternal programming of gene expression in utero may amplify intergenerational increases in weight but also amplify a stress-mediated susceptibility to abdominal obesity. The needed transformation in thinking on transport, environment, work facilities, education, health and food policies and perhaps in social and economic policies is unlikely when governments are wedded to individualism but without these changes to enhance physical activity and alter food quality societies are doomed to escalating obesity rates.

Restricting the energy intake of mice and rats slows the rate of actuarial aging, delays or prevents most age-associated disease processes, and maintains physiological processes in a youthful state at advanced ages. This manipulation is effective when initiated in young animals or in adult life. Although body fat is decreased by this reduction in energy intake, the reduction in body fat is not causally related to the antiaging action. Nor does this reduction in energy intake slow the aging processes by decreasing the metabolic rate, but it may do so by altering the characteristics of fuel use. Another possible mechanism underlying the antiaging action is the general protection restriction of energy intake provides against harmful agents, an action which may be the result of an alteration in adrenal glucocorticoid physiology.

It is apparent that personality is related to the pathogenesis of obesity, and that understanding the personality of the patient may be a key to successful treatment of the disease. Using the Rorschach test and interviews by a psychiatrist, the types of personality were classified into four groups according to the healthiness of personalities. The judgment of healthiness was based mainly on the scores obtained from the Rorschach test. This classification revealed that the occurrence of mental and physical symptoms during therapy with a very low calorie diet (VLCD) and subsequent rebound of bodyweight were more frequently observed in patients with relatively less healthy personalities. We used this classification to adapt our program to treat obese patients. In this program, severe diet restrictions were applied to patients with relatively healthy personalities. These restrictions were applied with modifications to patients with less healthy personality, because severe restrictions would be possibly very stressful for them and would bring about an undesirable reaction. For strengthening the patients' motivation for therapy, the significance of body weight reduction was explained in different ways to patients with different types of personality. The target of bodyweight reduction, reward for patients with successful weight reduction, and the duration of therapy were set up differently for patients with different personalities types. The results showed that bodyweight rebound one or two years after treatment was reduced with the personality-oriented therapy program compared to that observed with the previous conventional therapies. Also, the incidence of psychological problems was remarkably decreased.

This study examined the effect of weight loss (separate from energy restriction) and weight maintenance/rebound over time on blood pressure, serum lipids, and body composition in 24 obese (mean 137% ideal body weight (IBW)) females with mild to moderate hypertension. Weight loss was induced under tightly controlled General Clinical Research Center conditions until each subject had lost at least 10 kg (mean 13 kg) and attained normal body weight (< 120% IBW). After 4 years subjects returned for repeat evaluation. Weight changes were compared with 24 pair-matched normal weight controls who were also followed for 4 years. With weight loss, significant improvements were seen in standing mean arterial pressure (MAP), serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides. Subjects regained 11 kg (87% of the weight lost) over the 4 year follow-up period while control subjects gained only 2 kg. Subjects who chose self-selected exercise gained less weight than nonexercisers (6 kg vs. 13 kg, P < 0.05). With weight regain there were significant increases in standing and supine MAP, total cholesterol, and high-density lipoprotein (HDL) cholesterol. The amount of weight regained was significantly correlated with standing MAP (r = 0.73), triglycerides (r = 0.43), and HDL cholesterol (r = -0.47). The percentage fat of the weight regained was no greater than that of the weight previously lost. Weight loss, distinct from energy restriction, was associated with improvements in blood pressure and serum lipid levels. The ability to sustain these improvements in the co-morbidities of obesity was directly related to the persistence and magnitude of weight loss maintenance.

The effect of aerobic exercise on dietary compliance was assessed in 13 obese women (44 +/- 3% fat) during a 12-wk weight-reduction program (EX group). Seventeen obese women (45 +/- 5% fat) not engaged in aerobic exercise (NX group) served as control subjects. The reducing diets were designed to promote a weight loss of 1 kg/wk, with energy intakes individually prescribed (mean +/- SD: 4.9 +/- 0.6 MJ/d) to approximate 75% of each subject's measured basal metabolic rate. The EX group completed of three 45-min sessions/wk of supervised aerobic exercise at 65% of maximal oxygen consumption (VO2max). Daily energy intakes were calculated by summing changes in body stores, measured by total body water isotope dilution, and total daily energy expenditure, measured by doubly labeled water (DLW). Dietary compliance was assessed by comparing calculated intakes with prescribed intakes. Both the EX and NX groups reported consuming close to their prescribed daily intakes, with differences of -0.08 +/- 0.28 (EX group) and +0.03 +/- 0.57 (NX group) MJ/d, respectively. However, expenditure/balance data determined by the DLW method indicated that the EX subjects exhibited better dietary compliance than the NX subjects, with intakes exceeding those prescribed by only 0.7 +/- 1.5 compared with 2.3 +/- 1.6 MJ/d for the NX subjects (P = 0.01). Therefore, an additional benefit of aerobic exercise during energy restriction is enhanced dietary compliance, which has important implications for the treatment of moderate obesity.

Objective: To measure hepatic mitochondrial respiration as well as the ability of hepatic mitochondria to transport reducing equivalents by shuttle systems in rats fed an energy dense diet., Design: Rats were fed a control (CD) or energy dense (ED) diet for 15 days., Measurements: State 3 and State 4 oxygen consumption were measured in isolated mitochondria using glutamate+malate or pyruvate+malate as substrate. We also measured malate-aspartate shuttle activity and mitochondrial alpha-glycerophosphate dehydrogenase activity., Results: ED rats, in comparison with CD rats, showed a significantly greater energy intake without a corresponding greater body weight gain and carcass lipid content. Compared to CD rats, ED rats also showed a significant increase in resting metabolic rate, which was abolished by propranolol. Hepatic mitochondrial state 3 respiration using glutamate+malate or pyruvate+malate as substrate as well as malate-aspartate shuttle activity significantly decreased, while mitochondrial alpha-glycerophosphate dehydrogenase significantly increased in ED rats compared to CD rats., Conclusions: Mitochondrial NADH oxidation is reduced and a greater fraction of cytoplasmic NADH can be transported to the mitochondria through the alpha-glycerophosphate shuttle and oxidized through the respiratory chain from complex II onwards. This mechanism could lead to a decrease in hepatic metabolic efficiency which is in line with the increased energy expenditure occurring in rats fed an energy dense diet.

Objective: To investigate whether fat distribution or sex hormone status in overweight postmenopausal women do influence the response to treatment of overweight., Design: Longitudinal, clinical intervention study of a 4.2 MJ diet daily with or without exercise., Subjects: 98 healthy, overweight, postmenopausal women (age: 49-58 y, BMI: 25-42 kg/m2)., Measurements: Various fatness and fat distribution parameters (by dual-energy x-ray absorptiometry and anthropometry), sex hormone-binding globulin (SHBG), sex hormones, and the resting energy expenditure (REE) at baseline and after 3 months., Results: Reductions in weight and fat were independent of the initial fat distribution and the REE, but were significantly associated with high initial SHBG levels. Furthermore, loss of fat was significantly and independently associated with increases in SHBG and reductions in central fat distribution., Conclusion: Postmenopausal women with an android and gynoid fat distribution respond with similar weight loss to treatment of overweight. Furthermore, a more healthy, less android, fat distribution and sex hormone status may be achieved with increasing weight loss.

Objective: To determine, whether behavioral management of obesity including very-low-calorie-diet would produce weight loss enough to improve pulmonary mechanics and gas exchange in morbid obesity., Design: Pulmonary function and arterial oxygenation were studied before and after weight loss in 11 patients attending a group therapy with the program of VLCD for 6 weeks and 16 weeks' behavioral intervention., Measurements: Spirometry, diffusing capacity, body plethysmograph, closing volume and arterial blood gas analyses., Results: The mean initial BMI was 45.4 kg/m2 (range 39.8-58.7 kg/m2) and decreased to 39.4 kg/m2 (range 31-49.8 kg/m2) (P < 0.01). Expiratory reserve volume (ERV) and functional residual capacity (FRC) improved significantly with weight loss. Closing capacity (CC) exceeded FRC in 10 cases of 11 at the initial stage, but after weight loss only in three patients. The mean arterial oxygen tension with the patients in supine position did not change after weight loss, but standing up improved PaO2 significantly before and after weight loss., Conclusion: The dietary treatment of morbid obesity was sufficient to induce improvement in lung volumes, but not enough to improve arterial oxygenation, although ventilatory mechanics was improved significantly and the tendency to early small airway closure was decreased. Hypoxemia was significantly relieved by standing up both before and after weight loss.

Objective: To identify prognostic metabolic and hormonal markers for long-term weight loss outcome in obese women., Design: Dietary intervention consisting of 36 weeks treatment by a 4.2 MJ/d low-fat high carbohydrate diet, and follow-up 2 1/2 years after termination of treatment., Setting: Outpatient clinic in Copenhagen., Subjects: Forty consecutive female obese patients aged 15 to 62 years., Main Outcome Measure: Weight loss., Results: The maximum weight loss (mean 16.2 kg, 95% CI 14.2-18.2) was positively associated to pre-treatment 24-h energy expenditure (P < 0.01), fat oxidation (%) (P < 0.02), plasma dihydrotestosterone (DHT) (P < 0.01), and to postprandial noradrenaline concentration (P < 0.04). Together these factors could explain 41% of the variation in maximum weight loss. Only 24-h EE and DHT had predictive power on weight loss after 36 weeks. Weight losses in upper and lower tertiles of DHT concentrations were 17.7 kg (14.1-21.4) and 9.8 kg (6.2-13.3) (P < 0.02). The adjusted relative risk of losing < 10 kg in the upper compared to the lower DHT tertile was 12% (4-32%). At 2 1/2 y follow-up 21 patients had maintained some of the weight loss (54%), while 14 patients had maintained > 5 kg weight loss (36%). High levels of pre-treatment DHT were also associated with better weight loss at 2 1/2 y follow-up., Conclusion: The study suggests that in particular DHT, but also 24-h EE, fat oxidation, and plasma noradrenaline, may be prognostic markers for weight loss outcome in obese women.

Objective: To evaluate efficacy and tolerability of the lipase inhibitor Orlistat (Ro 18-0647) in doses of 10, 60 and 120 mg three times a day in addition to a mild hypocaloric diet containing 30% of calories as fat., Design: 4 week single-blind placebo run-in period of diet alone followed by a 12 week double-blind, placebo-controlled, randomized treatment period., Settings: Five European outpatient clinics specializing in endocrinology and/or the treatment of obesity, one central laboratory., Subjects: Of 237 healthy obese subjects meeting the inclusion criteria, 188 showed compliance to the diet during the run-in period and were randomized for the treatment period., Main Outcome Measures: Primary efficacy criterion was the difference in weight loss after 12 weeks of treatment between the Orlistat treated groups and the diet alone group. Secondary efficacy criteria were changes in serum total, HDL- and LDL-cholesterol., Results: Compared to placebo a mean (+/- s.e.) additional weight loss of 0.63 +/- 0.54 kg with 30 mg a day (P = 0.246), 0.71 +/- 0.55 kg with 180 mg a day (P = 0.190) and 1.75 +/- 0.54 kg with 360 mg a day was seen (P = 0.001) or Orlistat was observed. Overall data indicated dose-dependency. Small decreases were seen in total and LDL-cholesterol (significant in the 180 and 360 mg a day groups) and LDL- to HDL-cholesterol ratio (significant in the 360 mg a day group only). Mild, mostly gastrointestinal side effects were observed more frequently in the Orlistat groups and caused premature withdrawal from the study in only four patients. No marked laboratory abnormalities were shown, including the lipid-soluble vitamins A, D and E., Conclusion: Orlistat, in an apparently dose-dependent manner, leads to additional weight loss compared to diet alone and overall, is well tolerated.

Objective: To assess the effects, on food intake, body weight and body composition, of compliance to advice aiming at increasing the carbohydrate to fat ratio of the everyday diet without imposing voluntary restriction on the amount of food consumed., Design: Eight moderately overweight women (body mass index > 27 kg/m2, relative body fat mass > 30%) received dietary advice during a 2 month period. Additionally, each evening the subjects had to consume a meal artificially enriched with 13C-glucose in order to assess their compliance from the 13CO2 enrichment in expired air., Measurements: Dietary intakes, body weight, body composition and individual compliance., Results: The energy derived from fat decreased from 44 +/- 1% to 31 +/- 1% and the proportion of carbohydrate increased from 38 +/- 2% to 50 +/- 1%, whereas the absolute carbohydrate intake remained constant (182 +/- 18 g/d). Energy intake decreased by 1569 +/- 520 kJ/d. There was a net loss of fat mass (1.7 +/- 0.7 kg, P = 0.016) with fat free mass maintenance. Dietary compliance ranged from 20 to 93% (mean: 60 +/- 8%) and was positively correlated to the loss of body fat mass., Conclusion: Advice aiming at increasing diet's carbohydrate to fat ratio induces a loss of fat mass with fat-free mass maintenance.

Objective: The purpose of this study was to evaluate a simplified weight loss program in which subjects were provided a widely available meal replacement product and its package insert information (Ultra Slim-Fast)., Method: Weekly follow-up visits were carried out by non-physician personnel for weight measurement, distribution of product, and completion of a subjective questionnaire. No dietary counseling was provided. A total of 273 of 301 subjects (91%) completed 12 weeks of study. Men lost 50% (from 119 to 108% of ideal body weight) and women lost 35% (from 122 to 111% of ideal body weight) of excess body weight. Thirty-five patients who lost < 9 lbs in 12 weeks were considered non-adherent and were excluded from the next phase of the study during which 238 subjects were followed biweekly., Results: Despite a $25/week payment for participation nearly 44% of subjects dropped out or were judged non-compliant prior to the end of the study. At 116 weeks, 133 (97 females, 36 males) of 238 subjects remained in the study (44% of the initial population), with average weight loss from baseline of 13.6 +/- 10.5 lb in females and 14.0 +/- 10.5 lb in males., Discussion: The weight loss observed (approximately 10% of body weight) is significant and has been associated with important health benefits particularly for patients with hypertension and non-insulin dependent diabetes. The potential advantages of using meal replacements for mild obesity include wide availability to aid compliance, low cost and minimal professional intervention.

We modified criteria for judging successful obesity treatment proposed by Atkinson to provide objective criteria for successful benefit from weight reduction programs with respect to data from a clinical trial. The criteria include assessments of changes in both weight-related factors (e.g. excess weight, excess body fat) and obesity-related risk factors (e.g. hypertension, hyperglycemia, hyperlipemia). To demonstrate the use of this methodology, we applied the criteria in an analysis of eight randomized, double-blind controlled trials comparing fluoxetine (n = 522) with placebo (n = 504) for weight loss. The results suggest these criteria can be useful for evaluating a treatment program or for comparing treatments from clinical trials.

The aim of this work was to study the long-term effects of the addition of exercise to a short-term diet in overweight postmenopausal women. A follow up study was made of 118 overweight, postmenopausal women, who 6 months earlier had completed 12 weeks of randomized intervention (three groups: 4.2 MJ/d diet, 4.2 MJ/d diet with exercise, and controls). The following were measured: body composition and fat distribution (measured by dual-energy X-ray absorptiometry), resting metabolic rate, serum lipids and lipoproteins, blood pressure, and bone mineral densities. It was found that weight was still significantly reduced (by about 8 kg). HDL-C was significantly increased (10%), and triglycerides decreased (20%), whereas the initial reductions in total cholesterol and LDL-C had disappeared at the follow-up. The women from the former diet-plus-exercise group, who were current exercisers at the follow-up, had a significantly greater reduction in weight (10.9 vs 6.6 kg), fat tissue mass (10.0 vs 5.4 kg) and abdominal-to-total-body fat tissue mass (9.6 vs 4.7), and a significantly greater increase in the resting metabolic rate (11.1 vs 1.1 kJ/kg/d), as compared with the non-exercisers from this group. There were no major detrimental changes in total body, spinal, or forearm bone mineral density or in markers of bone turnover. The short-term dietary treatment in this study may have beneficial long-term effects on weight, fat tissue mass and cardiovascular risk factors with no additional benefits from added exercise, unless the exercise is continued.

Purpose: Wrestlers often engage in unhealthy practices to achieve a low body weight for competition. This study examined beliefs, practices, and potential support systems to promote safe weight loss among scholastic wrestlers., Methods: A written questionnaire was developed and administered to all nine high school wrestling teams in one rural county. Responses were obtained from 197 wrestlers., Results: Most wrestlers reported that "making weight" was very important. Increased activity and decreased food intake were the most frequent weight loss methods. Unsafe methods such as vomiting and use of laxatives were sometimes used, even though many wrestlers recognized these practices were unhealthy and decreased performance. Personal desire to win, coaches, and teammates were reported to be the greatest influences on weight loss efforts. Wrestlers believed that coaches and physicians were the most accurate sources of weight loss information., Conclusion: Nutrition counseling which goes beyond simply providing information about the risk of rapid weight loss among adolescent wrestlers is needed. Emphasis on motivating wrestlers to adopt healthy weight management strategies is important. Wrestlers perceive physicians as credible sources of information, and physicians should become more actively involved in educating both coaches and athletes about safe weight management.

Objective: To provide an overview of the published scientific information on the safety and efficacy of very low-calorie diets (VLCDs) and to provide rational recommendations for their use., Data Sources and Extraction: Original reports obtained through a MEDLINE search for 1966 through 1992 on VLCDs or reducing diets plus obesity, supplemented by a manual search of bibliographies and the opinions of experts in the field of nutrition and weight loss therapy for obesity. Only studies of humans were cited., Data Synthesis: Current VLCDs are usually provided in the context of comprehensive treatment programs, during which usual food intake is completely replaced by specific foods or liquid formulas containing 3350 kJ/d (800 kcal/d) or less. Weight loss on VLCDs averages 1.5 to 2.5 kg/wk; total loss after 12 to 16 weeks averages 20 kg. These results are superior to standard low-calorie diets of 5020 kJ/d (1200 kcal/d), which lead to weight losses of 0.4 to 0.5 kg/wk and an average total loss of only 6 to 8 kg. There is little evidence that intakes of less than 3350 kJ/d (800 kcal/d) result in better weight losses than 3350 kJ. Intake of at least 1 g/kg of ideal body weight per day of protein of high biologic value appears to be important in helping to preserve lean body mass. Serious complications of modern VLCDs are unusual, cholelithiasis being most common., Conclusions: Current VLCDs are generally safe when used under proper medical supervision in moderately and severely obese patients (body mass index [weight in kilograms divided by height in meters squared] > 30) and are usually effective in promoting significant short-term weight loss, with concomitant improvement in obesity-related conditions. Long-term maintenance of weight lost with VLCDs is not very satisfactory and is no better than with other forms of obesity treatment. Incorporation of behavioral therapy and physical activity in VLCD treatment programs seems to improve maintenance.