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BACKGROUND:Abdominal obesity predicts a wide range of adverse health outcomes. Over the past several decades, prevalence of abdominal obesity has increased markedly in industrialized countries like the United States No previous analyses, however, have evaluated whether there are birth cohort effects for abdominal obesity. Estimating cohort effects is necessary to forecast future health trends and understand the past population-level trends.METHODS:This analysis evaluated whether there were birth cohort effects for abdominal obesity for the Silent Generation (born 1925-1945), children of the Great Depression; Baby Boomers (born 1946-1964); or Generation X (born 1965-1980). Cohort effects for prevalence of abdominal obesity were estimated using the median polish method with data collected from the National Health and Nutrition Examination Survey (NHANES) between 1988 and 2008. Respondents were aged 20-74 years.RESULTS:After taking into account age effects and ubiquitous secular changes, the Silent Generation and Generation X had higher cohort-specific prevalence of abdominal obesity than the Baby Boomers. Effects were more pronounced in women than men.CONCLUSIONS:This work presents a novel finding: evidence that the birth cohorts of the post-World War II Baby Boom appeared to have uniquely low cohort effects on abdominal obesity. The growing prosperity of the post-World War II US may have exposed the baby-boom generation to lower levels of psychosocial and socioeconomic stress than the previous or subsequent generations. By identifying factors associated with the Baby Boomers' low cohort-specific sensitivity to the obesogenic environment, the obesity prevention community can identify early-life factors that can protect future generations from excess weight gain. [ABSTRACT FROM AUTHOR]

Background:Obesity prevalence stabilized in the US in the first decade of the 2000s. However, obesity prevalence may resume increasing if younger generations are more sensitive to the obesogenic environment than older generations.Methods:We estimated cohort effects for obesity prevalence among young adults born in the 1980s. Using data collected from the National Health and Nutrition Examination Survey between 1971 and 2008, we calculated obesity for respondents aged between 2 and 74 years. We used the median polish approach to estimate smoothed age and period trends; residual non-linear deviations from age and period trends were regressed on cohort indicator variables to estimate birth cohort effects.Results:After taking into account age effects and ubiquitous secular changes, cohorts born in the 1980s had increased propensity to obesity versus those born in the late 1960s. The cohort effects were 1.18 (95% CI: 1.01, 1.07) and 1.21 (95% CI: 1.02, 1.09) for the 1979-1983 and 1984-1988 birth cohorts, respectively. The effects were especially pronounced in Black males and females but appeared absent in White males.Conclusions:Our results indicate a generational divergence of obesity prevalence. Even if age-specific obesity prevalence stabilizes in those born before the 1980s, age-specific prevalence may continue to rise in the 1980s cohorts, culminating in record-high obesity prevalence as this generation enters its ages of peak obesity prevalence. [ABSTRACT FROM AUTHOR]

Background:No studies report whether improvements to commercial weight-loss programs affect retention and weight loss. Similarly, no studies report whether enrolling in a program through work (with a corporate partner) affects retention and weight loss.Objectives:To determine whether: (1) adding evidence-based improvements to a commercial weight-loss program increased retention and weight loss, (2) enrolling in a program through work increased retention and weight loss and (3) whether increased weight loss was because of longer retention.Design, Setting and Participants:Data were collected on 60 164 adults who enrolled in Jenny Craig's Platinum Program over 1 year in 2001–2002. The program was subsequently renamed the Rewards Program and improved by increasing treatment personalization and including motivational interviewing. Data were then collected on 81 505 participants of the Rewards Program who enrolled during 2005 (2418 of these participants enrolled through their employer, but paid out-of-pocket).Measurements:Retention (participants were considered active until 42 consecutive days were missed) and weight loss (percent of original body weight) from baseline to the last visit (data were evaluated through week 52) were determined.Results:Alpha was set at 0.001. Mean (95% confidence interval (CI)) retention (weeks) was significantly higher among Rewards (19.5 (19.4–19.6)) compared with Platinum (16.3 (16.2–16.4)) participants, and Rewards Corporate (25.9 (25.0–26.8)) compared with Noncorporate (21.9 (21.7–22.1)) participants. Modified intent-to-treat analyses indicated that mean (95% CI) percent weight loss was significantly larger among Rewards (6.36 (6.32–6.40)) compared with Platinum (5.45 (5.41–5.49)) participants, and Rewards Corporate (7.16 (6.92–7.40)) compared with Noncorporate (6.20 (6.16–6.24)) participants, with and without adjustment for baseline participant characteristics. In all cases, greater weight loss was secondary to longer retention.Limitations:The study was not a randomized controlled trial, rather, a translational effectiveness study.Conclusions:Improvements to a commercial program and enrolling through a corporate partner are associated with greater weight loss that is because of improved retention. [ABSTRACT FROM AUTHOR]

Objective:Develop a dose–response curve for the effect of intranasal lidocaine on food intake.Design:Healthy obese subjects had food intake, ratings of hunger, desire to eat, craving and fullness measured at lunch after an overnight fast. Four treatments were given as nose drops (0.5–0.6 ml per nostril) 5 min before the meal in a double-blind manner with a four period crossover design including a 7-day washout between periods. The treatments were saline, 2.5, 10 and 25 mg lidocaine per nostril. The order of administration was randomly assigned to each subject. Electrocardiograms, vital signs, chemistry panels, complete blood counts (CBC) and nasal inspections were carried out before and after each dose.Subjects:Forty-seven subjects were screened, 34 were randomized and 20 subjects completed all four study periods in the trial. The subjects were 39±12.5 (s.d) years of age, had a weight of 91±13.0 kg, a height of 167±10.3 cm, 56% were women, 47% were African-American and 53% were Caucasian.Measurements:Food intake, rating of hunger, desire to eat, craving and fullness are measures of efficacy. Adverse events, electrocardiograms, vital signs, chemistry panels, nasal inspections, CBC and physical exams are measures of safety.Results:The mean reduction in food intake vs saline control in the 20 subjects completing all four study periods was 3.3±7% (s.d), 4.2±8.5% and 7.4±7.3% in the 2.5 mg, 10 and 25 mg per nostril groups, respectively (P=NS). Hunger and desire to eat in subjects who completed at least one study period decreased dose dependently (P<0.03, at the 25 mg per nostril dose). There were no clinically significant changes in safety measures, electrocardiograms, vital signs, chemistry panels, CBC or nasal inspections.Conclusion:Intranasal lidocaine reduced hunger and the desire to eat, but this did not translate into a significant reduction in food intake suggesting that intranasal lidocaine will not have value in treating obesity.International Journal of Obesity (2007) 31, 858–863. doi:10.1038/sj.ijo.0803506; published online 28 November 2006 [ABSTRACT FROM AUTHOR]

Objective: A human pilot study testing the safety and effectiveness of NT (Number Ten), a dietary herbal supplement made from rhubarb, ginger, astragulus, red sage and turmeric, to reduce food intake and cause weight loss.Research Methods and Procedures: A total of 24 healthy women, 18-60 years, body mass index 25-35 kg/m(2) on no chronic medication were randomized to four groups of six: (1) oral freeze-dried NT 6 gm/day, (2) bed-dried NT 6 gm/day, (3) freeze-dried NT 12 gm/day or (4) placebo. Number Ten dose was escalated over 3 weeks and maintained for 8 weeks on a 700 kcal/day diet below maintenance. Food intake was measured at baseline and 4 weeks. Safety parameters were monitored weekly during dose escalation, week 6 and week 12.Results: Weight loss was 1.8 kg for placebo and 0.4 kg for 500 mg NT whereas the 250 mg bed- and freeze-dried NT gained 0.43 and 0.87 kg, respectively (P=NS). The food intake increased 74 kcal with 250 mg freeze-dried NT and decreased 193.7 kcal with 500 mg freeze-dried NT (P<0.01). There was a dose-related incidence of loose stools in the NT groups, but no other toxicity was seen. Number Ten was found to contain sennosides, known laxatives and gallic acid, which is known to give weight loss in rodents.Discussion: The human dose equivalent of NT used in this study was & frac16; and & frac112; of that shown to give well-tolerated weight loss in rodents. Number Ten will not be an effective dietary herbal supplement for the treatment of obesity owing to dose-limiting gastrointestinal toxicity. [ABSTRACT FROM AUTHOR]

Despite theoretical evidence that the model commonly referred to as the 3500-kcal rule grossly overestimates actual weight loss, widespread application of the 3500-kcal formula continues to appear in textbooks, on respected government- and health-related websites, and scientific research publications. Here we demonstrate the risk of applying the 3500-kcal rule even as a convenient estimate by comparing predicted against actual weight loss in seven weight loss experiments conducted in confinement under total supervision or objectively measured energy intake. We offer three newly developed, downloadable applications housed in Microsoft Excel and Java, which simulates a rigorously validated, dynamic model of weight change. The first two tools available at http://www.pbrc.edu/sswcp, provide a convenient alternative method for providing patients with projected weight loss/gain estimates in response to changes in dietary intake. The second tool, which can be downloaded from the URL http://www.pbrc.edu/mswcp, projects estimated weight loss simultaneously for multiple subjects. This tool was developed to inform weight change experimental design and analysis. While complex dynamic models may not be directly tractable, the newly developed tools offer the opportunity to deliver dynamic model predictions as a convenient and significantly more accurate alternative to the 3500-kcal rule. [ABSTRACT FROM AUTHOR]

A response from the authors of the article "Can a Weight Loss of a One Pound a Week Be Achieved With a 3500-kcal Deficit? Commentary on a Commonly Accepted Rule," in an issue of the "International Journal of Obesity" is presented.