References and Resources
For those who want more research and resources
Research Articles, more are added every year. Excellent reading material:
Effects of anti-obesity drugs, diet, and exercise on weight-loss maintenance after a very-low-calorie diet or low-calorie diet: a systematic review and meta-analysis of randomized controlled trials.
Weight-loss maintenance remains a major challenge in obesity treatment.
The objective was to evaluate the effects of anti-obesity drugs, diet, or exercise on weight-loss maintenance after an initial very-low-calorie diet (VLCD)/low-calorie diet (LCD) period (<1000 kcal/d).
We conducted a systematic review by using MEDLINE, the Cochrane Controlled Trial Register, and EMBASE from January 1981 to February 2013. We included randomized controlled trials that evaluated weight-loss maintenance strategies after a VLCD/LCD period. Two authors performed independent data extraction by using a predefined data template. All pooled analyses were based on random-effects models.
Twenty studies with a total of 27 intervention arms and 3017 participants were included with the following treatment categories: anti-obesity drugs (3 arms; n = 658), meal replacements (4 arms; n = 322), high-protein diets (6 arms; n = 865), dietary supplements (6 arms; n = 261), other diets (3 arms; n = 564), and exercise (5 arms; n = 347). During the VLCD/LCD period, the pooled mean weight change was -12.3 kg (median duration: 8 wk; range 3-16 wk). Compared with controls, anti-obesity drugs improved weight-loss maintenance by 3.5 kg [95% CI: 1.5, 5.5 kg; median duration: 18 mo (12-36 mo)], meal replacements by 3.9 kg [95% CI: 2.8, 5.0 kg; median duration: 12 mo (10-26 mo)], and high-protein diets by 1.5 kg [95% CI: 0.8, 2.1 kg; median duration: 5 mo (3-12 mo)]. Exercise [0.8 kg; 95% CI: -1.2, 2.8 kg; median duration: 10 mo (6-12 mo)] and dietary supplements [0.0 kg; 95% CI: -1.4, 1.4 kg; median duration: 3 mo (3-14 mo)] did not significantly improve weight-loss maintenance compared with control.
Anti-obesity drugs, meal replacements, and high-protein diets were associated with improved weight-loss maintenance after a VLCD/LCD period, whereas no significant improvements were seen for dietary supplements and exercise.
Regular exercise attenuates the metabolic drive to regain weight after long-term weight loss.
Weight loss is accompanied by several metabolic adaptations that work together to promote rapid, efficient regain. We employed a rodent model of regain to examine the effects of a regular bout of treadmill exercise on these adaptations. Obesity was induced in obesity-prone rats with 16 wk of high-fat feeding and limited physical activity. Obese rats were then weight reduced (approximately 14% of body wt) with a calorie-restricted, low-fat diet and maintained at that reduced weight for 8 wk by providing limited provisions of the diet with (EX) or without (SED) a daily bout of treadmill exercise (15 m/min, 30 min/day, 6 days/wk). Weight regain, energy balance, fuel utilization, adipocyte cellularity, and humoral signals of adiposity were monitored during eight subsequent weeks of ad libitum feeding while the rats maintained their respective regimens of physical activity. Regular exercise decreased the rate of regain early in relapse and lowered the defended body weight. During weight maintenance, regular exercise reduced the biological drive to eat so that it came closer to matching the suppressed level of energy expenditure. The diurnal extremes in fuel preference observed in weight-reduced rats were blunted, since exercise promoted the oxidation of fat during periods of feeding (dark cycle) and promoted the oxidation of carbohydrate (CHO) later in the day during periods of deprivation (light cycle) . At the end of relapse, exercise reestablished the homeostatic steady state between intake and expenditure to defend a lower body weight. Compared with SED rats, relapsed EX rats exhibited a reduced turnover of energy, a lower 24-h oxidation of CHO, fewer adipocytes in abdominal fat pads, and peripheral signals that overestimated their adiposity. These observations indicate that regimented exercise altered several metabolic adaptations to weight reduction in a manner that would coordinately attenuate the propensity to regain lost weight.
Prior weight loss exacerbates the biological drive to gain weight after the loss of ovarian function.
Both the history of obesity and weight loss may change how menopause affects metabolic health. The purpose was to determine whether obesity and/or weight loss status alters energy balance (EB) and subsequent weight gain after the loss of ovarian function. Female lean and obese Wistar rats were randomized to 15% weight loss (WL) or ad libitum fed controls (CON). After the weight loss period, WL rats were kept in EB at the reduced weight for 8 weeks prior to ovariectomy (OVX). After OVX, all rats were allowed to eat ad libitum until weight plateaued. Energy intake (EI), spontaneous physical activity, and total energy expenditure (TEE) were measured with indirect calorimetry before OVX, immediately after OVX, and after weight plateau. Changes in energy intake (EI), TEE, and weight gain immediately after OVX were similar between lean and obese rats. However, obese rats gained more total weight and fat mass than lean rats over the full regain period. Post-OVX, EI increased more (P ≤ 0.03) in WL rats (58.9 ± 3.5 kcal/d) than CON rats (8.5 ± 5.2 kcal/d), and EI partially normalized (change from preOVX: 20.5 ± 4.2 vs. 1.5 ± 4.9 kcal/day) by the end of the study. As a result, WL rats gained weight (week 1:44 ± 20 vs. 7 ± 25 g) more rapidly (mean = 44 ± 20 vs. 7 ± 25 g/week; P < 0.001) than CON Prior obesity did not affect changes in EB or weight regain following OVX, whereas a history of weight loss prior to OVX augmented disruptions in EB after OVX, resulting in more rapid weight regain.
Attenuating the Biologic Drive for Weight Regain Following Weight Loss: Must What Goes Down Always Go Back Up?
Metabolic adaptations occur with weight loss that result in increased hunger with discordant simultaneous reductions in energy requirements-producing the so-called energy gap in which more energy is desired than is required. The increased hunger is associated with elevation of the orexigenic hormone ghrelin and decrements in anorexigenic hormones. The lower total daily energy expenditure with diet-induced weightloss results from (1) a disproportionately greater decrease in circulating leptin and resting metabolic rate (RMR) than would be predicted based on the decline in body mass, (2) decreased thermic effect of food (TEF), and (3) increased energy efficiency at work intensities characteristic of activities of daily living. These metabolic adaptations can readily promote weight regain. While more experimental research is needed to identify effective strategies to narrow the energy gap and attenuate weight regain, some factors contributing to long-term weightloss maintenance have been identified. Less hunger and greater satiation have been associated with higher intakes of protein and dietary fiber, and lower glycemic load diets. High levels of physical activity are characteristic of most successful weight maintainers. A high energy flux state characterized by high daily energy expenditure and matching energy intake may attenuate the declines in RMR and TEF, and may also result in more accurate regulation of energy intake to match daily energy expenditure.
diet composition; energy expenditure; energy gap; energy intake; exercise; weight regain
Beneficial effects of exercise: shifting the focus from body weight to other markers of health.
Exercise is widely promoted as a method of weight management, while the other health benefits are often ignored. The purpose of this study was to examine whether exercise-induced improvements in health are influenced by changes in body weight.
Fifty-eight sedentary overweight/obese men and women (BMI 31.8 (SD 4.5) kg/m(2)) participated in a 12-week supervised aerobic exercise intervention (70% heart rate max, five times a week, 500 kcal per session). Body composition, anthropometric parameters, aerobic capacity, blood pressure and acute psychological response to exercise were measured at weeks 0 and 12.
The mean reduction in body weight was -3.3 (3.63) kg (p<0.01). However, 26 of the 58 participants failed to attain the predicted weight loss estimated from individuals’ exercise-induced energy expenditure. Their mean weight loss was only -0.9 (1.8) kg (p<0.01). Despite attaining a lower-than-predicted weight reduction, these individuals experienced significant increases in aerobic capacity (6.3 (6.0) ml/kg/min; p<0.01), and a decreased systolic (-6.00 (11.5) mm Hg; p<0.05) and diastolic blood pressure (-3.9 (5.8) mm Hg; p<0.01), waist circumference (-3.7 (2.7) cm; p<0.01) and resting heart rate (-4.8 (8.9) bpm, p<0.001). In addition, these individuals experienced an acute exercise-induced increase in positive mood.
These data demonstrate that significant and meaningful health benefits can be achieved even in the presence of lower-than-expected exercise-induced weight loss. A less successful reduction in body weight does not undermine the beneficial effects of aerobic exercise. From a public health perspective, exercise should be encouraged and the emphasis on weight loss reduced.
- PMID: 19793728 DOI: 10.1136/bjsm.2009.065557
Diet or exercise interventions vs combined behavioral weight management programs: a systematic review and meta-analysis of direct comparisons.
Weight loss can reduce the health risks associated with being overweight or obese. However, the most effective method of weight loss remains unclear. Some programs emphasize physical activity, others diet, but existing evidence is mixed as to whether these are more effective individually or in combination. We aimed to examine the clinical effectiveness of combined behavioral weight management programs(BWMPs) targeting weight loss in comparison to single component programs, using within study comparisons. We included randomized controlled trials of combined BWMPs compared with diet-only or physical activity-only programs with at least 12 months of follow-up, conducted in overweight and obese adults (body mass index ≥25). Systematic searches of nine databases were run and two reviewers extracted data independently. Random effects meta-analyses were conducted for mean difference in weight change at 3 to 6 months and 12 to 18 months using a baseline observation carried forward approach for combined BWMPs vs diet-only BWMPs and combined BWMPs vsphysical activity-only BWMPs. In total, eight studies were included, representing 1,022 participants, the majority of whom were women. Six studies met the inclusion criteria for combined BWMP vs diet-only. Pooled results showed no significant difference in weight loss from baseline or at 3 to 6 months between the BWMPs and diet-only arms (-0.62 kg; 95% CI -1.67 to 0.44). However, at 12 months, a significantly greater weight-loss was detected in the combined BWMPs (-1.72 kg; 95% CI -2.80 to -0.64). Five studies met the inclusion criteria for combined BWMP vs physical activity-only. Pooled results showed significantly greater weight loss in the combined BWMPs at 3 to 6 months (-5.33 kg; 95% CI -7.61 to -3.04) and 12 to 18 months (-6.29 kg; 95% CI -7.33 to -5.25). Weight loss is similar in the short-term for diet-only and combined BWMPs but in the longer-term weight loss is increased when diet and physical activity are combined. Programs based on physical activity alone are less effective than combined BWMPs in both the short and long term.
Behavioral programme; Diet; Exercise; Obesity; Weight loss
Long–term effectiveness of diet–plus–exercise interventions vs. diet–only interventions for weight loss: a meta-analysis.
Diet and exercise are two of the commonest strategies to reduce weight. Whether a diet–plus–exercise intervention is more effective for weight loss than a diet–only intervention in the long–term has not been conclusively established. The objective of this study was to systemically review the effect of diet–plus–exercise interventions vs. diet–only interventions on both long–term and short-term weight loss. Studies were retrieved by searching MEDLINE and Cochrane Library (1966 – June 2008). Studies were included if they were randomized controlled trials comparing the effect of diet–plus–exercise interventions vs. diet–only interventions on weight loss for a minimum of 6 months among obese or overweight adults. Eighteen studies met our inclusion criteria. Data were independently extracted by two investigators using a standardized protocol. We found that the overall standardized mean differences between diet–plus–exercise interventions and diet–onlyinterventions at the end of follow-up were -0.25 (95% confidence interval [CI]-0.36 to -0.14), with a P-value for heterogeneity of 0.4. Because there were two outcome measurements, weight (kg) and body mass index (kg m(-2)), we also stratified the results by weight and body mass index outcome. The pooled weight loss was 1.14 kg (95% CI 0.21 to 2.07) or 0.50 kg m(-2) (95% CI 0.21 to 0.79) greater for the diet–plus–exercise group than the diet–only group. We did not detect significant heterogeneity in either stratum. Even in studies lasting 2 years or longer, diet–plus–exercise interventions provided significantly greater weight loss than diet–only interventions. In summary, a combined diet–plus–exercise programme provided greater long–term weight loss than a diet–only programme. However, both diet–only and diet–plus–exercise programmes are associated with partial weight regain, and future studies should explore better strategies to limit weight regain and achieve greater long–term weight loss.
- PMID: 19175510 DOI: 10.1111/j.1467-789X.2008.00547.x
The effect of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women: a systematic review protocol.
What are the effects of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women?The primary objective of this systematic review is to evaluate the effectiveness of weightmanagement interventions which include a diet component and are aimed at limiting gestational weight gain and postpartum weight retention in women.The second objective of this systematic review is to investigate included intervention components with respect to effect on weight-related outcomes. This may include, but is not limited to: length of intervention, use of face-to-face counselling, group or individual consultations, use of other interventions components including exercise, use of goals and use of support tools like food diaries, coaching, including email or text message support.
Around half of all women of reproductive age are either overweight or obese, with women aged 25-34 years having a greater risk of substantial weight gain compared with men of all ages. Excessive gestational weight gain (GWG) and postpartum weightretention (PPWR) may play a significant role in long term obesity. Having one child doubles the five- and 10-year obesity incidence for women, with many women who gain excessive weight during pregnancy remaining obese permanently. Excessive GWG and/or PPWR can also significantly contribute to short- and long-term adverse health outcomes for mother, baby and future pregnancies.Maternal obesity increases the risk of pregnancy related complications such as pre-eclampsia, gestational diabetes mellitus, stillbirth and the rate of caesarean section. Childhood obesity is a further long term complication of maternal obesity for offspring, which may persist in to adulthood. Excess GWG is also a risk factor for PPWR both in the short and long-term. Nehring et al. conducted a meta-analysis with over 65,000 women showing that, compared to women who gained weight within recommendations during pregnancy, women with GWG above Institute of Medicine weight gain recommendations, retained an additional 3.1 kg and 4.7kg after three and greater than or equal to 15 years postpartum, respectively. The health risk associated with PPWR is highlighted in a study of 151,025 Swedish women followed between 1992 and 2001.The study identified the risk of adverse pregnancy outcomes for those who gained three or more units of Body Mass Index (kg/m2) between consecutive pregnancies (an average of two years) was much higher compared with women whose BMI changed from -1.0 and 0.9 units. Long-term chronic disease risk may also be affected by PPWR as weight retention at the end of the first year post-partum has been found to be a predictor of maternal overweight 15 years later.With around 14-20% of women retaining 5kg or more 12 months postpartum, the risk of developing conditions like diabetes, metabolic syndrome and cardiovascular disease may be increased. It becomes evident that interventions which aim to support attainment of healthy weight both in the antenatal and postpartum periods are key health priorities for women during this life stage.Lifestyle factors of overweight, having poor diet quality, and not undertaking enough moderate-to-vigorous physical activity are amongst the top five predictors of mortality in women. Additionally it is noted that, for many women, pregnancy and the postpartum period are associated with a reduction in physical activity. It is known that a combination of poor dietary choices, an increase in sedentary time and reduction in physical activity are all contributors to the development of overweight and obesity. With this in mind, current research has focused on lifestyle interventions to limit GWG and PPWR. Thangaratinam et al. reviewed 44 randomized controlled trials (7278 women) where interventions including diet, physical activity or both were evaluated for their influence on maternal weight during pregnancy. Results indicate that all were significantly effective in reducing GWG compared with the control group. More specifically, dietary interventions were the most effective in reducing weight gain, with a mean weight loss of -3.84kg compared with -0.72kg and -1.06kg for physical activity and the mixed (diet plus physical activity) approach, respectively. This finding is supported by Hill and colleagues’ recent systematic review of theory based interventions to limit GWG. Included studies in this review reported an underpinning theory base and were classified as adopting a dietary, physical activity or mixed approach. Hill et al. concluded that studies which included a diet intervention were significantly more effective at limiting GWG.In 2011 Tanentsapf et al. reviewed the effect of dietary interventions alone for reducing GWG in normal weight, overweight and obese pregnant women. This review analysed 13 randomized controlled trials and quasi-randomized controlled trials with a dietary intervention to prevent excessive GWG in women. The review concluded that dietary interventions during pregnancy were effective in reducing GWG with an effect of -1.92kg (n=1434) compared with the control group.Tanentsapf et al. identified that trials differed in the conduct of the interventions with various diet and non-diet related components utilised. Dietary approaches were highly variable with some trials focusing only on calorie restriction and others included additional target macronutrient distribution for intake. Some trials further provided feedback based on maternal weight gain guidelines. Interventions also varied in delivery method with a variety of modes used, including face-to-face, individual or group consultations and/or written correspondence. The frequency of communication, despite the type or mix, also changed from trial to trial with additional methods via telephone, posted materials, feedback or food diaries utilised. The inclusion of physical activity in addition to diet intervention was also common. Whilst the recent review by Tanentsapf et al. identified that dietaryinterventions are effective in reducing GWG, the review did not investigate the impact that different intervention components, delivery methods or dietary counselling approaches had on gestational weight management. It remains unclear as to which intervention components optimize GWG in women.The impact of lifestyle interventions has also been investigated in the postpartum period. The recent systematic review from van der Pligt et al. reported seven of 11 studies reviewed were successful in limiting PPWR. As with studies aimed at limiting GWG, interventions included in van der Pligt et al.’s review differed greatly in their conduct. Six of these seven studies included both dietaryand physical activity components for the intervention, with the final successful study including a diet only intervention. Five of the successful studies recruited overweight or obese women only. Intervention time varied considerably in successful studies with some running for as little at ten days, and others up to six months.Bertz et al. demonstrated that their 12-week behavior modification intervention which targeted dietalone or diet and exercise, including two individual sessions with a dietitian and physical therapist, provision of scales for weight self-monitoring and bi-weekly text messages was successful in achieving significant weight loss following the intervention, and sustained at one year. The diet intervention and the diet and exercise intervention yielded significant weight loss compared to the control. Following 12 weeks a reduction of -8.3 +/- 4.2kg for diet intervention and -6.9 +/- 3.0kg for diet and exercise was observed. Additionally after one year, the dietintervention showed -10.2 +/- 5.7kg reduction and -7.3 +/- 6.3kg for the diet and exercise intervention (p<0.001). Colleran et al. also found significant weight change results by implementing a 16-week intervention which consisted of weekly individual sessions with a dietitian regarding calorie restriction, two additional home visits regarding exercise, weekly food diary completion and email support. The intervention group had greater weight loss compared to the control group (-5.8kg +/- 3.5kg vs -1.6kg +/- 5.4kg). It can be seen that various methods have been utilized in investigating the impact of diet and physical activity interventions on PPWR. The review by van der Pligt et al. highlights the impact successful lifestyle interventions can have on postpartum weight change. However, this review did not investigate the different intervention strategies utilized. It remains unclear as to the optimal setting, delivery method, diet strategy, contact frequency or intervention length to limit PPWR.Previous systematic reviews for both GWG and PPWR have focused on the effectiveness of lifestyle interventions as a whole for weight management in pregnant and postpartum women. And despite Tanentsapf et al.’s focus on dietary interventions for GWG, much is still unknown about the effectiveness of differing diet interventions over the antenatal and postpartum period. Specifically, the impact of differing diet intervention strategies on maternal weight gain is not known. Firstly, this systematic review will focus on whether weightmanagement interventions which include a dietary component are effective in pregnant and postpartum women. In addition to this, this review will investigate the different intervention strategies utilized and their effectiveness in maternal weight management. A search of systematic review protocol databases has shown that there is no current review underway for this topic.
- PMID: 26447010 DOI: 10.11124/jbisrir-2015-1812
Meta-analysis: the effect of dietary counseling for weight loss.
Dietary and lifestyle modification efforts are the primary treatments for people who are obese or overweight. The effect of dietary counseling on long-term weight change is unclear.
To perform a meta-analysis of the effect of dietary counseling compared with usual care on body mass index (BMI) over time in adults.
Early studies (1980 through 1997) from a previously published systematic review; MEDLINE and the Cochrane Central Register of Controlled Trials from 1997 through July 2006.
English-language randomized, controlled trials (> or =16 weeks in duration) in overweight adults that reported the effectof dietary counseling on weight. The authors included only weight loss studies with a dietary component.
Single reviewers performed full data extraction; at least 1 additional reviewer reviewed the data.
Random-effects model meta-analyses of 46 trials of dietary counseling revealed a maximum net treatment effect of -1.9 (95% CI, -2.3 to -1.5) BMI units (approximately -6%) at 12 months. Meta-analysis of changes in weight over time (slopes) and meta-regression suggest a change of approximately -0.1 BMI unit per month from 3 to 12 months of active programs and a regain of approximately 0.02 to 0.03 BMI unit per month during subsequent maintenance phases. Different analyses suggested that calorie recommendations, frequency of support meetings, inclusion of exercise, and diabetes may be independent predictors of weight change.
The interventions, study samples, and weight changes were heterogeneous. Studies were generally of moderate to poor methodological quality. They had high rates of missing data and failed to explain these losses. The meta-analytic techniques could not fully account for these limitations.
Compared with usual care, dietary counseling interventions produce modest weight losses that diminish over time. In future studies, minimizing loss to follow-up and determining which factors result in more effective weight loss should be emphasized.
- PMID: 17606960
Long-term weight loss after diet and exercise: a systematic review.
To assess the effectiveness of dietary interventions and exercise in long-term weight loss in overweight and obese people.
A systematic review with meta-analysis.
Overweight and obese adults-18 years old or older with body mass index (calculated as weight divided by the square of height in meters)>25.
Medline, Cochrane Library and Lilacs databases up to March 2003. Also, published reviews and all relevant studies and their reference lists were reviewed in search for other pertinent publications. No language restrictions were imposed.
Randomised clinical trials comparing diet and exercise interventions vs diet alone. All trials included a follow-up of 1 y after intervention.
Two reviewers independently abstracted data and evaluated the studies’ quality with criteria adapted from the Jadad Scale and the Delphi list.
The estimate of the intervention’s effect size was based on the differences between the comparison groups, and then the overall effect was calculated. A chi-squared test was used to assess statistical heterogeneity.
A total of 33 trials evaluating diet, exercise or diet and exercise were found. Only 6 studies directly comparing diet and exercise vs diet alone were included (3 additional studies reporting repeated observations were excluded). The active intervention period ranged between 10 and 52 weeks across studies. Diet associated with exercise produced a 20% greater initial weight loss. (13 kg vs 9.9 kg; z=1.86-p=0.063, 95%CI). The combined intervention also resulted in a 20% greater sustained weight loss after 1 y (6.7 kg vs 4.5 kg; z=1.89-p=0.058, 95%CI) than diet alone. In both groups, almost half of the initial weight loss was regained after 1 y.
Diet associated with exercise results in significant and clinically meaningful initial weight loss. This is partially sustained after 1 y.
- PMID: 15925949 DOI: 10.1038/sj.ijo.0803015
Systematic review: an evaluation of major commercial weight loss programs in the United States.
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.
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.
Review of company Web sites, telephone discussion with company representatives, and search of the MEDLINE database.
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 were extracted on study design, attrition, weight loss, duration of follow-up, and maintenance of weight loss.
We found studies of eDiets.com, Health Management Resources, Take Off Pounds Sensibly, OPTIFAST, and WeightWatchers. 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.
Because many studies did not control for high attrition rates, the reported results are probably a best-case scenario.
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.
- Review: little evidence supports the efficacy of major commercial and organised self help weight loss programmes. [Evid Based Nurs. 2005]
- Commercial weight loss programs. [Ann Intern Med. 2005]
- There is insufficient evidence about the efficacy of commercial weight loss programmes. Commentary. [Evid Based Cardiovasc Med. 2005]
- Review: little evidence supports the efficacy of major commercial and organized self-help weight loss programs. [ACP J Club. 2005]
Summary for patients in
- Summaries for patients. Evaluation of the major commercial weight loss programs. [Ann Intern Med. 2005]
- PMID: 15630109
Commercial Programs’ Online Weight-Loss Claims Compared to Results from Randomized Controlled Trials.
To characterize weight-loss claims and disclaimers present on websites for commercial weight-loss programs and compare them with results from published randomized controlled trials (RCTs).
A content analysis of all home pages and testimonials available on the websites of 24 randomly selected programs was performed. Two team members independently reviewed each page and abstracted information from text and images to capture relevant content, including demographics, weight loss, and disclaimers. A systematic review was performed to evaluate the efficacy of these programs by searching MEDLINE and the Cochrane Database of Systematic Reviews, and the mean weight change from each RCT included was abstracted.
Overall, the amount of weight loss portrayed in the testimonials was extreme across all programs examined (range median weight loss 10.7-49.5 kg). Only 10 out of the 24 programs had eligible RCTs. Median weight losses reported in testimonials exceeded that achieved by trial participants. Most programs with RCTs (78%) provided disclaimers stating that the testimonial’s results were nontypical and/or gave a range of typical weight loss.
Weight-loss claims within testimonials were higher than results from RCTs. Future studies should examine whether commercial programs’ advertising practices influence patients’ expectations or satisfaction with modest weight-loss results.
© 2017 The Obesity Society.
Metabolic response to experimental overfeeding in lean and overweight healthy volunteers.
Possible adaptive mechanisms that may defend against weight gain during periods of excessive energy intake were investigated by overfeeding six lean and three overweight young men by 50% above baseline requirements with a mixed diet for 42 d [6.2 +/- 1.9 MJ/d (mean +/- SD), or a total of 265 +/- 45 MJ]. Mean weight gain was 7.6 +/- 1.6 kg (58 +/- 18% fat). The energy cost of tissue deposition (28.7 +/- 4.4 MJ/kg) matched the theoretical cost (26.0 MJ/kg). Basal metabolic rate (BMR) increased by 0.9 +/- 0.4 MJ/d and daily energy expenditure assessed by whole-body calorimetry (CAL EE) increased by 1.8 +/- 0.5 MJ/d. Total free-living energy expenditure (TEE) measured by doubly labeled water increased by 1.4 +/- 2.0 MJ/d. Activity and thermogenesis (computed as CAL EE–BMR and TEE–BMR) increased by only 0.9 +/- 0.4 and 0.9 +/- 2.1 MJ/d, respectively. All outcomes were consistent with theoretical changes due to the increased fat-free mass, body weight, and energy intake. There was no evidence of any active energy-dissipating mechanisms.
- PMID: 1414963
Comparison of traditional and nontraditional weight loss methods: an analysis of the national health and nutrition examination survey.
To evaluate the real-world use of various weight loss techniques and to compare the effectiveness of nontraditional methods with diet and exercise in helping nongeriatric adults lose weight.
A cross-sectional analysis of the 2005-2010 National Health and Nutrition Examination Survey was performed. Adult, nonpregnant participants aged 20 to 65 years with a body mass index of ≥ 18.5 who tried to lose weight in the previous year were analyzed (weighted n = 53,570,979). Outcome measures included the proportion of patients who used nontraditional weight loss methods and a comparison of weight loss between those who used diet and exercise and those who used nontraditional methods.
During the previous year, 56.9% (95% confidence interval 54.5-59.4) of participants used nontraditional methods (nonexclusive of diet and exercise) as their attempted weight loss methods. Overall, individuals gained a mean (standard error) of 4.9 (0.3) lb in the 12 months preceding the National Health and Nutrition Examination Survey questionnaire. Only 19.6% (95% confidence interval 18.0-21.2) of the sample lost weight within the previous 12 months. Those who used nontraditional methods gained more weight during the previous year than those who used diet and exercise only (for body mass index ≥ 18.5, 5.5 vs 3.5 lb; P < 0.01) in the overall sample, but there was no difference in the obese subgroup.
Physicians need to reaffirm that diet and exercise are better methods for weight loss, and they need to advise their patients to avoid other methods when attempting to lose weight because they do not enhance weight loss attempts.
- PMID: 25010580 DOI: 10.14423/SMJ.0000000000000130