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Muscle fiber type is associated with obesity and weight loss.
The purpose of this study was to test the hypothesis that muscle fiber type is related to obesity. Fiber type was compared 1) in lean and obese women, 2) in Caucasian (C) and African-American (AA) women, and 3) in obese individuals who lost weight after gastric bypass surgery. When lean (body mass index 24.0 +/- 0.9 kg/m(2), n = 28) and obese (34.8 +/- 0.9 kg/m(2), n = 25) women were compared, there were significant (P < 0.05) differences in muscle fiber type. The obese women possessed fewer type I (41.5 +/- 1.8 vs. 54.6 +/- 1.8%) and more type IIb (25.1 +/- 1.5 vs. 14.4 +/- 1.5%) fibers than the lean women. When ethnicity was accounted for, the percentage of type IIb fibers in obese AA was significantly higher than in obese C (31.0 +/- 2.4% vs. 19.2 +/- 1.9%); fewer type I fibers were also found in obese AA (34.5 +/- 2.8% vs. 48.6 +/- 2.2%). These data are consistent with the higher incidence of obesity and greater weight gain reported in AA women. With weight loss intervention, there was a positive relationship (r = 0.72, P < 0.005) between the percentage of excess weight loss and the percentage of type I fibers in morbidly obese patients. These findings indicate that there is a relationship between muscle fiber type and obesity.
Blood pressure and pulse pressure during long-term weight loss in the obese: the Swedish Obese Subjects (SOS) Intervention Study.
OBJECTIVE: Recently we reported a complete relapse in the blood pressure (BP) of obese subjects despite a maintained 16% weight loss over 8 years. This relapse is now analyzed as a function of several variables. Pulse pressure (PP) is an independent risk factor of cardiovascular mortality. We now examine the development of PP in the obese and whether it can be modified by weight-reducing gastric surgery. RESEARCH METHODS AND PROCEDURES: A total of 1157 patients treated with gastric surgery and 1031 obese controls (body mass index of 41.0 +/- 4.6 kg/m(2) [mean +/- SD], age 48 +/- 6 years) were followed for 5.5 +/- 2.1 (range 3 to 10) years. To separate the effect of weight change from effect of time on BP, the patients were divided in cohorts based on follow-up time. RESULTS: Gastric surgery resulted in a maximum weight loss after 1 year that was followed by a moderate relapse. After 5.5 years, weight loss in the intervention group was 18 +/- 11% of initial body weight. Very little weight change was seen in controls. Systolic BP decreased in the intervention group during the first 6 months but had relapsed to control values at last examination. The adjusted change in PP was +4.7 mm Hg in obese controls but +2.9 mm Hg in the intervention group (p < 0.001). Final BP values were more closely related to follow-up time and ongoing weight increase than to initial body weight or initial weight loss. DISCUSSION: Effects of time (aging) and weight change per year on BP can be separated. An early increase in PP could be observed in the obese. This increase could be modified by weight-reducing gastric surgery.
Effects of gastric acid on euro coins: chemical reaction and radiographic appearance after ingestion by infants and children.
OBJECTIVES: This study investigated whether coins of the new European currency (euro) corrode when they are exposed to gastric acid, and whether this change can be detected radiographically. METHODS: The eight different denominations of coins were immersed for seven days in 0.15 N hydrochloride acid (HCl), which corresponds to the level of post-prandial gastric acid. A Swedish crown coin and three different Austrian schilling coins were used as controls. The coins were weighed and radiographed daily to evaluate visible corrosions and HCl was analysed daily for possible dissolved substances. RESULTS: All coins lost weight within 24 hours after exposure to HCl. The 1, 2, and 5 euro cent coins developed changes that were visible on radiographs. The weights of all coins decreased by 0.43% to 11.30% during one week. The dissolved substances measured in the HCl corresponded to the different metals and alloys of the coins, except for copper, which does not dissolve in HCl. The highest absolute weight loss was observed in the Swedish crown coin (0.67 g), and the highest relative weight loss in the 1 Austrian schilling coin (11.30%). The two coins that showed the highest absolute and relative weight losses were the 2 euro (0.54 g or 6.35%) and the 1 euro (0.48 g or 6.39%) coin. CONCLUSIONS: A higher rate of toxicity for the new European coins compared with coins of other currencies is not expected, unless a massive coin ingestion occurs.
Rorschach personality predictors of weight loss with behavior modification in obesity treatment.
weight loss outcome for 49 obese patients after 6 months treatment in a behavior modification program was related to Rorschach personality characteristics according to the Comprehensive System (Exner, 2003), also including the Rorschach Oral Dependency Scale (Bornstein, 1996; Masling & Rabie, 1967). Less weight loss was predicted by signs of perceptual and cognitive distortions indicated by the Schizophrenia Index. More weight loss was predicted by Food Contents, suggesting a food preoccupation and possibly a benign dependency orientation. Patients with a focus on food and dependent needs could benefit above all from the treatment program implying learning how to handle food and eating in a supportive setting, as evidenced by more weight loss. Distortions in perception and cognition could constitute more profound difficulties in weight reduction important to recognize in obesity treatment.
Referral sources to a weight management program: relation to outcome.
OBJECTIVE: To examine the characteristics and outcomes of physician-referred weight management patients relative to self-referred patients. DESIGN: Review of clinic records of all individuals contacting a weight control program during a 2-year period with follow-up throughout consecutive levels of treatment (i.e., enrollment, completion, and outcome). SETTING: Medical school weight management center. PARTICIPANTS: A consecutive sample (N = 1,392) of overweight and obese callers was categorized as physician-initiated (n = 345), media (n = 653), or personal (n = 394) referrals. Attendees at initial consultation (n = 571) were age 41.7 +/- 12.8 years, weight 113.9 +/- 36.1 kilograms, and body mass index (BMI) 40.3 +/- 11.3 kg/m(2) (data expressed as mean +/- standard deviation). INTERVENTIONS: Low-calorie-diet and very-low-calorie-diet programs. MAIN OUTCOME MEASURES: Gender comparisons, attendance at initial consultation, body mass index, motivation, comorbidities, enrollment and completion rates, and weight loss. RESULTS: Compared to callers from other referral sources, physician referrals included a larger minority of males (25.2%) and were more likely to attend an initial consultation (63.5%; P < .001). Among consultation attendees, physician referrals were heavier (mean BMI = 44.8), reported more comorbidities, were less likely to join programs (16.9%), and scored as less motivated than other referrals (P < .007). Completion rates for physician referrals were higher than for self-referrals in the very-low-calorie-diet program (85.7%; P < .04) but not in the low-calorie-diet program (P > .05). Among completers, physician referrals did not differ on weight loss in either program (P > .05). CONCLUSIONS: Compared to self-referrals, physician-referred individuals are in greater need of weight loss, less motivated, less likely to enter treatment, but equally likely to profit from it. Therefore, physician referral for weight loss is beneficial for at least some patients and should be encouraged.
Diet and physical activity behavior among users of prescription weight loss medications.
BACKGROUND: There is limited population-based data on diet and physical activity behaviors and weight loss among users of prescription weight loss medications. Most findings are from clinical settings or from research that includes organized behavioral programs. METHODS: We analyzed data from the 1998 Behavioral Risk Factor Surveillance System, an annual telephone survey conducted in all fifty states, the District of Columbia and Puerto Rico. The sample consisted of 135,435 noninstitutionalized adults aged 18 years old and older. We determined the prevalence and odds of prescription weight loss medication use, odds of 10% weight loss, and among current weight loss medication users, the prevalence and odds for diet and physical activity behaviors. RESULTS: 10.2% of obese women and 3.1% of obese men reported using prescription weight loss medications in the past 2 years. Of users, 28.2% had lost at least 10% of their pretreatment body weight. The odds of losing at least this much weight were higher among women, those who usually consumed >/= 5 fruits and vegetables daily and those who met physical activity recommendations. Among current prescription weight loss medication users, 26.7% reported both eating fewer calories and meeting recommended leisure-time physical activity levels (<40% of any group met both). Of those meeting both recommendations, almost half (47.2%) had lost 10% of their pretreatment body weight. Of current users, 9% reported using the medications for weight maintenance. CONCLUSIONS: Only 26.7% of prescription weight loss medication users reported following recommended diet and physical activity behaviors. Further research is needed to assess whether behavioral changes are associated with greater weight loss and maintenance among prescription weight loss medication users.
Elevated intramyocellular lipid concentration in obese subjects is not reduced after diet and exercise training.
To determine the effects of weight loss on intramyocellular energy substrates, vastus lateralis muscle biopsies were taken from six obese subjects (body mass index 34 +/- 5 kg/m(2)) before, after 15 wk of energy restriction (ER; -700 kcal/day), and after a further average 20.7 +/- 1.6 wk of endurance training plus low-fat diet (ET-LFD). Body weight fell from 100 +/- 6 to 89 +/- 6 kg during ER and to 84 +/- 4 kg after ET-LFD. Lipids and glycogen were histochemically measured in type I, IIA, and IIB fibers. Total muscle glycogen content (MGC; per 100 fibers) decreased after ER [from 72 +/- 13 to 55 +/- 8 arbitrary units (AU)]. A similar but not significant decrease was seen in total muscle lipid content (MLC; 14 +/- 5 to 9 +/- 1 AU). After ET-LFD, MGC returned to initial values (74 +/- 8 AU), and MLC approached near-initial values (12 +/- 3 AU). Individual fiber lipid concentration did not change throughout the protocol in all fiber types, whereas glycogen concentration increased after ET-LFD. The training effects of ET-LFD were measured as increasing activities of key mitochondrial enzymes. Although total muscle energy reserves can be reduced after weight loss, their concentration within individual myofibers remains elevated. weight loss does not appear sufficient to correct the potential detrimental effects of high intracellular lipid concentrations.
Weight change, body weight and mortality: the impact of smoking and ill health.
OBJECTIVES: This paper examines the influence of cigarette smoking and ill health on the relationship between weight change, body weight and subsequent mortality to determine whether weight loss and leanness in middle to older age is deleterious to health. METHODS: Men aged 40-59 years at screening drawn from one general practice in each of 24 British towns, who completed a questionnaire 5 years after screening (Q5) and provided full information on changes in weight and smoking status (n = 7065) were then followed up for an average of 13.8 years. RESULTS: In all men a shallow U-shaped relationship was seen between body mass index (BMI) at Q5 and all-cause mortality rates. weight loss and substantial weight gain (> or =10%) were associated with increased mortality rates compared to the stable weight group. The increased risk associated with weight loss was seen in long- term non-smokers (n = 4101) and recent ex-smokers (n = 722) but not in current smokers (n = 2242) after adjustment for a wide range of potential confounders. However, the increased risk was markedly attenuated after exclusion of those with ill health (relative risk [RR] = 1.16, 95% CI : 0.84-1.59 and RR = 0.79, 95% CI : 0.29-2.20 for long-term non-smokers and recent ex-smokers, respectively). Moderate weight gain (4-10%) was associated with lower risk of mortality than observed in those with stable weight but only in recent ex-smokers and in current smokers, not in long-term non-smokers. A positive association was seen between BMI at Q5 and all-cause mortality in non-smokers and this was strengthened by exclusion of men with weight loss. CONCLUSION: The increased risk of mortality associated with weight loss or low body weight in middle-aged and older men appears to be a direct consequence of ill health leading to weight loss and leanness. In healthy non-smoking men weight loss and leanness are not associated with increased mortality and moderate weight gain (4-10%) was neither deleterious nor beneficial.
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