Family Practice Vol. 21, No. 3, 324-328
Family Practice Vol. 21, No. 3 © Oxford University Press 2004, all rights reserved.
Selections from Current Literature |
The spectrum of treatment options for obesity
Department of Family Medicine, Health Sciences Center, L-4 R050, State University of New York, Stony Brook, NY 11794, USA
Nemerson L, Danowski L and Trilling JS. The spectrum of treatment options for obesity. Family Practice 2004; 21: 324–328.
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Introduction |
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 Top Introduction Phelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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Throughout the world there are currently more than 1 billion overweight adults. At least 300 million of these are clinically obese.1 An estimated 64% of US adults are either overweight or obese as defined by a body mass index (BMI)
25. This represents an 8% increase since the NHANES III 1988–1994 data. Obesity, defined as a BMI 30.0, has risen from 15% in 1980 to 27% in 1999 as reflected by the NHANES 1999 and NHANES II 1976–1980 data.2,3 The cost associated with conditions of overweight and obesity, in the USA, was >$117 billion in 2000.4 Obesity is a complex condition with a multifactorial aetiology elusive to intervention. Traditional treatment options do not always yield favourable outcomes, the resultant general perception being that successful long-term maintenance of weight loss is rare.
The National Weight Control Registry (NWCR) evaluates the weight loss and weight maintenance strategies of successful ‘weight loss maintainers’. There are >3000 subjects in the NWCR database. On average, the weight loss reported by participants is 30 kg, and the average duration of weight maintenance is 5.5 years.5
Surgical interventions for the morbidly obese have increased steadily since first introduced almost 50 years ago. A patient currently investigating this option has multiple procedures to consider that vary by mechanism of action. There currently is no surgical procedure preferred by consensus. Instead, preference varies by surgeon and location. By way of example, nutrient intake-restrictive procedures such as the Roux-en-Y gastric bypass are most popular in the USA, while restrictive procedures such as adjustable gastric bands are much more common in Europe and Australia.6
Alteration of calorie levels and macronutrient distributions have also been assessed as interventions to effect weight loss. Intuitively, caloric restriction would be expected to foster weight loss. However, data imply that a very low carbohydrate diet, even without specified reduction of caloric intake, is effective over a 6-month period. When compared with a low fat diet conforming to the currently recommended distribution of macronutrient calories, the very low carbohydrate diet yielded significantly greater weight loss. Caloric intake was similar for the two groups. The implication is that dietary differences in weight loss cannot be expressed solely as a function of caloric intake.7
Given the health and economic impact of the conditions of overweight and obesity, as well as confusion and controversy over their intervention and management, our purpose in this ‘Selections’ is to provide an overview of the most current treatment options.
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Phelan S, Hill JO, Lang W, Dibello JR, Wing RR. Recovery from relapse among successful weight maintainers. Am J Clin Nutr 2003; 78: 1079–1084 |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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The authors examined NWCR participants' weight change patterns over 2 years to determine how frequently patients who regained weight recovered, and to examine prospectively variables characteristic of those who recovered compared with those who did not. The NWCR is voluntary and participants are recruited through television, radio, magazine and newspaper advertisements. Of the 4122 registry participants enrolled, 3234 reached their 2-year follow-up point: 2492 completed the 2-year assessment. There were significant differences at baseline between study withdrawals and those who remained. Study withdrawals were younger, weighed more, had a higher BMI and had lost more weight upon entry into the registry.
Self-reported pregnancies were excluded from the final sample, with a resultant sample size of 2400, 80% of which were women, 96% Caucasian. On average, subjects had lost an average of 32.1 ± 17.8 kg and had maintained their weight loss for 6.5 ± 8.1 years before enrolling into the registry.
Three time points were considered in this study. Initial enrolment in the study was referred to as ‘baseline’; time corresponding to 1 year after entry was referred to as ‘year 1’; and time corresponding to 2 years after entry was referred to as ‘year 2’. ‘Regain’ was defined as weighing any amount above baseline at years 1 and 2. ‘Full recovery’ was defined as weighing more than at baseline at year 1 but losing weight and returning to baseline or below by year 2. ‘Relapsers’ were those defined as weighing 5% above baseline weight at year 1 and more than their year 1 weight at year 2. ‘Partial recovery’ was defined as gaining 5% at year 1 but losing 50% of the year 1 gain by year 2. ‘Maintenance’ was defined as maintaining weight at or below baseline for 2 years.
Subjects were required to give a complete weight history. Validated instruments were used to assess behavioural and psychological measures.
Subjects gained an average of 3.8 ± 7.6 kg between baseline and year 2. At year 2, most participants (72.2%) were above their baseline weight. Of note is that 99.6% of this sample remained well below their maximum lifetime weight and 96.4% remained 10% below their maximum lifetime weight. Between baseline and year 1, 65.7% of the sample population gained weight above baseline. Only 11% of this population returned to baseline weight or below at year 2. Recovery from relatively small weight gains was rare, and larger weight gains further reduced the chances of recovery. Only 17.5% of subjects that gained between 1 and 3% of their initial body weight by year 1 were able to return to baseline or below by year 2. Only 14.4% of subjects who gained 3–5% of their initial body weight at year 1 were at baseline or below by year 2. Of the population, 25.5% were considered ‘relapsers’, having gained 5% between baseline and year 1. Only 12.9% of those ‘re-lost’ at least half of their year 1 gain by year 2. Full recovery occurred in only 4.7% of participants.
Two key points implied by these data are that: (i) rate of weight gain by year 1 was the strongest predictor of outcome; and (ii) depressed patients are at risk for continued weight gain.
Comments
The investigators concluded that small weight ‘regains’ are common and that few subjects recover from even small lapses of 1–2 kg. These small fluctuations in weight may be considered normative. Despite these findings, the weight gains were modest and 96.4% of the sample remained >10% below their lifetime maximum weight. These subjects are still considered successful by current obesity treatment standards.8 A large sample size and prospective design, which allowed identification of who was at risk for recovery or regain, were major strengths of this study. A limitation to consider might be that assessments were performed annually, making it difficult to capture events immediately preceding weight gain or factors related to recovery. Additionally, despite the 77% follow-up rate, a response bias remains possible, as subjects who had gained weight may have been prone to withdraw.
Two key points to take away from this study are that any weight gain should be prevented, and that monitoring a patient's depressive symptoms may help identify patients at risk for continued weight gain.
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Zinzindohoue F, Chevallier JM, Douard R et al. Laparoscopic gastric banding: a minimally invasive surgical treatment for morbid obesity. Ann Surg 2003; 237: 1–9 |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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As the prevalence of obesity continues to climb, so has interest in surgical intervention options. The goal of this study was to assess the safety and efficacy of laparoscopic adjustable gastric banding performed on 500 consecutive patients in the surgical unit of a Paris hospital. The decision to operate was made by a multidisciplinary team using NIH criteria for bariatric surgery.
A total of 438 women and 62 men with a mean age of 40.4 years were included. Mean body weight was 120.6 kg with a mean BMI of 44.3. Seventy-two percent of subjects had co-morbid conditions relating to their overweight condition. These included hypertension, diabetes, dyslipidaemia, degenerative joint disease, sleep apnoea and respiratory disease.
At 24-month follow-up, quality of life, co-morbidities and patient satisfaction were assessed. Operative time averaged 105 min, 84 min during the last 300 procedures, with a mean hospital stay of 4.5 days. There were no deaths and no subjects were lost to follow-up. A total of 94 patients experienced complications (18.8%) with 14 doing so shortly after surgery and 80 during follow-up. Among the 52 patients requiring repeat surgery, three involved major complications, i.e. gastric necrosis and two perforations that required oesophageal suturing.
Weight loss results were positive and encouraging. ‘Excessive weight loss’, defined as the difference between the patient's actual weight and the theoretical ideal body weight, was 42.8, 52 and 54.8 at years 1, 2 and 3 consecutively. Average BMI decreased from 44.3 to 31.9 at year 3. Of the 343 patients with at least 1-year follow-up, 16 were considered to be failures, losing <20% of their excessive body weight. Subsequently, 11 of them were found to be poor candidates for the procedure as their profile revealed that they displayed compulsive bulimic behaviour or were ‘sweet eaters’.
Quality of life was determined by the ‘Bariatric Analysis and Reporting Outcome System’ (BAROS). It uses a point system analysing three main criteria: weight loss, medical outcomes and quality of life. A total of 140 subjects were available for analysis, with 76% of patients reporting significant improvements in quality of life after 6 months of weight loss. Six percent reported no improvement, 18% reported a fair improvement, 49% reported good improvement and 27% reported excellent results.
Comments
Strides continue to be made in surgical weight loss interventions. Interestingly, the last 300 study patients experienced fewer complications than the first 200, allegedly by altering surgical technique to reduce band slippages.
For the segment of the population with morbid obesity, laparoscopic gastric banding presents a relatively safe and effective method for weight loss. In comparison with other surgical procedures, it results in less morbidity and mortality, as well as less dramatic weight loss. Traditional gastric bypass produces a more substantial weight loss of 55% at year 1 and 70% at year 5. However, the low rate of major complications (0.6%) and significant weight loss results makes laparoscopic gastric banding a good alternative to more risky and permanent procedures such as gastric bypass. The procedure is potentially reversible, thus allowing the patient to return to a natural anatomic state after achieving weight goal and diet re-education. Additional outcome research regarding long-term weight maintenance and risk is needed.
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Foster GD, Wyatt HR, Hill JO et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med 2003; 348: 2082–2090 |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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The Atkins diet has become increasingly popular despite controversy over safety and efficacy. This multi-centre, randomized, controlled trial evaluated a low carbohydrate, high-protein, high-fat Atkins diet as a weight loss and risk factor intervention for coronary heart disease in obese subjects. A total of 63 subjects participated in the study. Subjects completed routine blood tests and physical examination prior to initiation. Each site randomly assigned subjects to a low carbohydrate, high-protein, high-fat Atkins diet, or a high-carbohydrate, low-fat, energy-deficit, conventional diet. Each group met with a registered dietitian to review the components of each diet. The low-carbohydrate diet did not restrict protein or fat. The conventional diet provided 1200–1500 kcal per day for women and 1500–1800 kcal per day for men. This diet provided
60% calories from carbohydrate, 25% from fat and 15% from protein. Body weight was measured at baseline and at 2, 4, 8, 12, 16, 20, 26, 34, 42 and 52 weeks. Blood pressure and urinary ketones were assessed at baseline and 2, 4, 8, 12, 16, 20, 26, 34, 42 and 52 weeks. Blood samples to determine serum lipoprotein concentrations were obtained after an overnight fast at baseline and 3, 6 and 12 months. Oral glucose tolerance tests were performed at baseline and 3, 6 and 12 months. In addition, insulin sensitivity was assessed. Weight loss in the low-carbohydrate diet group compared with the conventional group was significantly higher at 3 and 6 months but not statistically significant at 12 months. This was found to be true in the analysis in which baseline values were carried forward in the case of missing values, the analysis that included data on subjects who completed the study, and data obtained at the last follow-up for subjects who did not complete the study. Fifty-nine percent of subjects completed the study. The drop-out rate was higher in the conventional diet group than the low-carbohydrate group, but the differrence was not statistically significant. The percentage of patients who tested positive for urinary ketones was significantly higher in the low-carbohydrate group than the conventional diet group during the first 3 months. No significant differences in urinary ketones were detected between groups after 3 months. No significant difference was found between weight loss and ketosis at any time during this study. There were no significant differences between the conventional and low-carbohydrate groups with regard to insulin sensitivity. Both groups showed significant increases in insulin sensitivity at 6 months, but values were not significantly different from baseline by year 1. Total cholesterol and low-density lipoprotein (LDL) cholesterol concentrations showed no significant differences except at month 3, where values were significantly lower in the conventional diet group. A relative increase in high-density lipoprotein (HDL) cholesterol concentrations and a relative decrease in triglyceride concentrations were noted in the low-carbohydrate group compared with the conventional diet group throughout most of the study.
Comments
These data imply that the low-carbohydrate, high-protein, high-fat Atkins diet resulted in greater weight loss than a conventional diet for up to 6 months. Additionally, the lack of statistical significance for weight loss after 6 months was most probably due to greater weight ‘regain’ in the low-carbohydrate group and may reflect poor long-term compliance with the low-carbohydrate diet. Lack of statistical significance may also be related to the small sample size. Only 37 out of 63 subjects completed the year-long trial. Greater weight loss in the low-carbohydrate, high-protein, high-fat Atkins diet was attributed to a greater energy deficit, despite unrestricted protein and fat. However, no food records were kept during the study to substantiate this statement. Limited contact with health professionals was intentional in an attempt to reproduce dieting conditions of the general population. These data additionally suggest that ketosis was not responsible for increased weight loss in the low-carbohydrate diet, as no relationship was found between the presence of urinary ketones and weight loss. In the final analysis, it is uncertain what overall effect a low-carbohydrate diet has on coronary risk factors. Some improvement of serum lipoproteins was seen (serum triglycerides decreased and HDL cholesterol increased), but not others (LDL cholesterol did not decrease). It is also uncertain what clinical significance a decreased triglyceride and increased HDL level has in the setting of a high fat intake. In conclusion, the long-term effects of a high-fat diet, and low intake of fruits, vegetables and fibre imposed by a low-carbohydrate diet still remain to be seen. There are other significant clinical end points not addressed in this trial. These may include possible effects, adverse or positive, on renal function, bone health, exercise tolerance, cancer or cardiovascular function.
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Lantz H, Peltonen M, Agren L, Torgerson JS. Intermittent versus on-demand use of a very low calorie diet: a randomized 2-year clinical trial. J Intern Med 2003; 253: 463–471 |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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Amongst the multitude of weight loss strategies, long-term success can vary tremendously. Another common treatment for obesity is a very low calorie diet (VLCD). While the use of a VLCD appears to produce significant initial results acutely, this current randomized 2-year trial focused on utilization of VLCD during the maintenance phase. According to the authors, it is the first study to observe the use of VLCD on-demand during the maintenance phase. This was a randomized 2-year clinical trial conducted at Sahlgrenska University Hospital of 334 patients between the ages of 18 and 60 with a BMI >30 who entered the study by referral. Exclusion criteria included concomitant serious diseases, previous obesity surgery, drug abuse or participation in other clinical trials. Subjects were randomized to two treatment groups. The first was an ‘intermittent’ group in which a VLCD was instituted according to a fixed, predetermined schedule throughout the maintenance period. In the second group, subjects self-applied VLCD ‘on-demand’ as opposed to a fixed schedule, based on a predetermined weight gain cut-off point, during the maintenance period.
Both groups initially received a 16-week VLCD period of 450 calories per day. Following the initial treatment period, all subjects participated in a ‘refeeding’ phase in which solid food was reintroduced for a 3-week period. Subjects were then counselled on an individual basis to adhere to a restricted calorie diet for the remaining 2 years of the study. The ‘intermittent’ group was scheduled to resume the VLCD for 2 weeks every third month. Alternatively, the ‘on-demand’ group resumed the VLCD when their weight rose above a predetermined cut-off level. All subjects had consistent communication with study staff, including 21 scheduled visits with a nurse, 11 visits with a dietitian and an office visit with a physician at randomization and then every 6 months during the study period.
One hundred and seventeen subjects completed the trial (35%), with no difference between drop-out rates from either group or gender. The difference in weight loss at the end of the initial 16-week period was not significant between groups. The intermittent group lost 20.6 kg or 18.3% while the on-demand group experienced a 22.0 kg loss or 19.0%. At the conclusion of the study, those numbers fell to 7.0 kg (6.2%) and 9.1 kg (7.7%), respectively. In total, after 2 years, 44% of those in the intermittent group and 62% in the on-demand group maintained a weight loss of at least 5%.
Comments
Statistically significant risk improvements have been observed in both diabetic and hypertensive patients who achieve >10% weight loss, and in patients with cardiovascular conditions who achieve 5% weight loss.9
Overall, participants in this current study maintained a mean weight loss of 7% after 2 years. Not surprisingly, cardiovascular risk factors improved. While there was no statistical difference between the treatment groups, subgroup analysis demonstrated a difference in female-to-male outcomes, as well as male-to-male treatment groups. Men in the ‘intermittent’ group maintained a weight loss of 4.0 kg. Men in the ‘on-demand’ group maintained a 14.5 kg weight loss. In contrast, females in the ‘intermittent’ group maintained an 8.0 kg weight loss, and the ‘on-demand’, 6.2 kg. The differences between male treatment groups may be partially explained by the small number of male study completers; however, the investigators could not explain the difference between genders.
In comparison, weight loss in this current trial was slightly lower than previous data in which weight loss has ranged between 7.5 and 10%. A shortcoming of this study, however, was lack of a control group.
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Conclusions |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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In this review, we offer patients and clinicians information on some of the more current treatment options for overweight and obese patients, accompanied by known risks and benefits. In the case of surgical interventions, small weight gains may be considered normal. The amount of weight ‘regain’ within the first year appears to be the strongest predictor of outcome. Depressive symptoms are also strongly related to weight regain. Further research regarding correlation between depression and obesity is needed. Despite some discouraging results with weight maintenance, at 2 years 96.4% of subjects tend to remain at >10% below their maximum lifetime weight. While surgical interventions may have the benefit of being long lasting, they are not without risk. Male gender and ‘super-obesity’ appear to be the most significant predictors of severe life-threatening complications following gastric bypass. Although the morbidity rate is similar in older and younger patients, subjects over 55 years of age appear to have a 3-fold higher mortality rate relative to younger patients.10 Achieved weight loss at year 1, 2 and 3 was 42.8, 52 and 54.8%, respectively, as reviewed. BMI decreased on average from 44.3 at baseline to 31.9 at year 3. Although these results are promising, they are accompanied by an 18.8% complication rate; however, only 0.6% of these are considered major.
Another intervention, the low-carbohydrate diet, has gained increased popularity in recent years. Safety and efficacy issues remain and long-term studies are needed. The study addressed in this review demonstrated weight loss within the first 6 months after institution of a low-carbohydrate diet. Long-term effects, however, of a low-carbohydrate, high-protein and high-fat diet on lipid profiles are as yet unavailable. Questions remain regarding the mechanism of weight loss, as ketosis, interestingly, was not a significant finding during restriction of carbohydrates in subjects. To recommend with confidence a diet limited in fruit, vegetables and fibre would require more investigative studies.
Another dietary intervention, VLCDs, may have positive effects on cardiovascular risk factors and result in significant weight losses after 2 years. Male subjects may benefit from an on-demand VLCD strategy. An intermittent versus on-demand strategy had no apparent affect on weight loss.
Many advances have been made in the management of the overweight and obese patient. Further studies on the horizon hope to elucidate the most effective treatment of this growing epidemic, but as yet have not done so.
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References |
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TopIntroductionPhelan S, Hill JO,...Zinzindohoue F, Chevallier JM,...Foster GD, Wyatt HR,...Lantz H, Peltonen M,...ConclusionsReferences |
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1 World Health Organization. Joint WHO/FAO expert consultation on diet, nutrition and the prevention of chronic disease (2002). Retrieved January 6, 2004 from www.who.int/nut/documents/trs_916.pdf
2 Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999–2000. J Am Med Assoc 2002; 288: 1723–1727.
3 Centers for Disease Control. Overweight and obesity among adults. Retrieved January 5, 2004, from http://www.cdc.gov/nccdphp/dnpa/obesity/defining.htm
4 US Department of Health and Human Services. The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity. Rockville (MD): US Department of Health and Human Services, Public Health Service, Office of the Surgeon General; 2001.
5 Wing RR, Hill JO. Successful weight loss maintenance. Annu Rev Nutr 2001; 21: 323–341.[CrossRef][Web of Science][Medline]
6 Kim J, Tarnoff M, Shikora S. Surgical treatment of extreme obesity: Evolution of a rapidly growing field. Nutr Clin Pract 2003; 18: 109–123.
7 Brehm BJ, Seeley SR, Daniels SR, D'Alessio DA. A Randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003; 88: 1617–1623.
8 National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Obesity Res 1998; 6: 51S–210S.[Web of Science][Medline]
9 Kanders BS, Blackburn GL, Lavin P. Weight loss outcome and health benefits associated with the Optifast program in the treatment of obesity. Int J Obesity 1989; 13: 131–134.
10 Livingston EH, Huerta S, Arthur D, Lee S, De Shields S, Heber D. Male gender is a predictor of morbidity and age a predictor of mortality for patients undergoing gastric bypass surgery. Ann Surg 2002; 236: 576–582.[CrossRef][Web of Science][Medline]
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