Bibliografía

Methods used to conduct the pan-European Union survey on consumer attitudes to physical activity, body weight and health.

Autor:
Kearney JM, Kearney MJ, McElhone et al.

Abstract:
The purpose of conducting this survey was to identify data on consumer attitudes towards and beliefs about physical activity, body weight and health among the 15 countries of the EU. DESIGN: A cross-sectional study to get a picture of the attitudes to physical activity, body weight and health in the EU. For this, it was considered important that samples be nationally representative so that inferences drawn from the data could be applied to the population in each country as well as to the EU population as a whole. Using a non-probability sampling method employing quota controls (and the national weight) we obtained large sample sizes from each country which were nationally representative in terms of the variables age, sex and regional distribution. To ensure samples were truly nationally representative a national weight was used when analysing the data using the same characteristics as those used to define quotas. When examining pooled estimates for the total EU sample a population weight was applied. RESULTS: In total, 15,239 subjects aged 15 years and upwards in the EU completed the survey. This article gives details on the methods used in carrying out the survey from design of the questionnaire to sample selection, questionnaire administration and analysis of the data. The methods and their limitations are discussed.

Referencia bibliográfica:
Public Health Nutr. 1999 Mar; 2(1A):79-86.

The size of obesity differences associated with educational level in Spain

Autor:
Gutierrez-Fisac JL, Regidor E, Banegas Banegas JR, et al.

Abstract:
OBJECTIVE: To determine the size of obesity differences associated with educational level in the adult population in Spain. DESIGN: Three cross sectional studies representative of the adult population in Spain were carried out in 1987, 1995, and 1997. SETTING: The general population in Spain. PARTICIPANTS: 11 461 men and 10 219 women aged 25 to 64 years. MAIN RESULTS: For both men and women the obesity prevalence was highest in those with elementary education. In 1987 the obesity prevalence proportion associated with less than third level education (PA) was 24.5% (95% CI 6.0 to 42.8) and 47.9% (15.7 to 71.8) in men and women, respectively. The PAs in 1995/97 were 19.8% (0.2 to 40.2) and 55.1% (21.3 to 72.8). CONCLUSIONS: In 1995/97 the burden of obesity associated with less than third level education was 20% in men and 55% in women aged 25 to 64 years. Between 1987 and 1997 the obesity prevalence proportion associated with less than third level education increased in women and decreased in men.

Referencia bibliográfica:
J Epidemiol Community Health. 2002 Jun;56 (6):457-60

Prevalencia de la obesidad en Europa.

Autor:
Varo JJ, Martínez-González MA y Martínez JA.

Abstract:
The prevalence of obesity is increasing in an alarming way, while that of other risk factors (hyperlipaemia, arterial hypertension.) are tending to diminish. Amongst all of the factors involved in its development, two are outstanding because of their potential for modification: an excessive calorie intake and a sedentary life style, in spite of the recommendations in favour of regularly practising physical exercise. The principal problem in studying the prevalence of obesity is the scarcity of studies that analyse it in a global form. In 1989 the first results of the MONICA project of the WHO were published, with the observation that the prevelence was higher for men than for women, and that it was greater in the Mediterranean countries and the east of Europe, in comparison with the north and centre-west. In 1997 a study was carried out by the Institute of European Food Studies (IEFS) in which 15,239 individuals participated proceding from representative samples of the 15 Member States of the European Union. Its results showed that the higher prevalence of obesity was to be found in the United Kingdom (12%), followed by Spain (11%), while it was lower in Italy, France and Sweden (7%). By sex, the prevalence of obesity is somewhat greater amongst women, while overweightedness was greater amongst men. In Spain the distribution of overweighted and obesity amongst the different socio-economic groups is similar to that of other regions, with the percentage of obesity being highest amongst the elderly, subjects of a lower socio-economic level and the inhabitants of the north and north-west of Spain.

Referencia bibliográfica:
An Sist Sanit Navar. 2002;25 (Suppl 1):103-108

Consenso SEEDO´2000 para la evaluación del sobrepeso y la obesidad y el establecimiento de criterios de intervención terapéutica.

Autor:
Sociedad Española para el Estudio de la Obesidad (SEEDO).

Abstract:
No disponible

Referencia bibliográfica:
Nutrición y Obesidad 2000; 6: 285-299

The relationship of overweight and obesity with subjective health and use of health-care services among Spanish women.

Autor:
Guallar Castillón P, López Garcia E, Lozano Palacios L, et al.

Abstract:
OBJECTIVE: To examine the relationship of overweight and obesity with subjective health and use of health-care services among women in Spain. METHODS: Data were drawn from the 1993 Spanish National Health Survey, covering a 13 244-woman sample representative of the non-institutionalised Spanish population aged 16 y and over. Information was collected through home-based interviews. Multiple logistic regression models were used to calculate odds ratios for suboptimal health (fair, poor or very poor) and utilisation of health-care services by women with normal weight (BMI 18.5-24.9 kg/m(2)), overweight (BMI 25.0-29.9 kg/m(2)) and obesity (BMI>or=30 kg/m(2)). Analyses were adjusted for age, education level, occupation, civil status, social support, tobacco use, alcohol consumption, physical activity at work and during leisure time, job status and town of residence. RESULTS: Frequency of suboptimal health was higher in women with overweight (OR 1.7; 95% CI 1.5-1.9) and obesity (OR 2.1; 95% CI 1.8-2.5) than in those with normal weight. Overweight and obese women visited the physician, used hospital emergency services and took medication with greater frequency than did women of normal weight. There was a positive dose-response relationship (P<0.05) of BMI>or=18.5 kg/m(2) with suboptimal health and utilisation of health-care services. These associations were not wholly explained by BMI-related risk factors and chronic diseases, since their statistical significance remained unchanged and their magnitude was only slightly reduced after adjustment for those factors. The association of overweight and obesity with the use of health-care services did not vary with age, educational level or presence of chronic disease. CONCLUSION: Overweight and obese women have worse subjective health and make greater use of health-care services. This finding is an additional argument for implementing weight-control programmes in Spain.

Referencia bibliográfica:
Int J Obes Relat Metab Disord. 2002 Feb;26(2):247-52.

The obesity epidemic: pathophysiology and consequences of obesity.

Autor:
Pi-Sunyer FX.

Abstract:
Obesity has reached epidemic proportions in the United States: more than 20% of adults are clinically obese as defined by a body mass index of 30 kg/m(2) or higher, and an additional 30% are overweight. Environmental, behavioral, and genetic factors have been shown to contribute to the development of obesity. Elevated body mass index, particularly caused by abdominal or upper-body obesity, has been associated with a number of diseases and metabolic abnormalities, many of which have high morbidity and mortality. These include hyperinsulinemia, insulin resistance, type 2 diabetes, hypertension, dyslipidemia, coronary heart disease, gallbladder disease, and certain malignancies. This underscores the importance of identifying people at risk for obesity and its related disease states.

Referencia bibliográfica:
Obes Res. 2002 Dec;10 Suppl 2:97S-104S.

What to do about the metabolic syndrome?

Autor:
Hill JO and Bessesen D.

Abstract:
No disponible

Referencia bibliográfica:
Arch Intern Med. 2003 Feb 24;163(4):395-7.

Treatment for patients with metabolic syndrome.

Autor:
Ginsberg, HN.

Abstract:
The metabolic syndrome, or insulin resistance syndrome, is associated with increased risk for cardiovascular disease and related mortality and has an estimated age-adjusted US prevalence of 23.7%. Dyslipidemia in the syndrome is characterized by hypertriglyceridemia, low high-density lipoprotein cholesterol, and small, dense low-density lipoprotein (LDL) particles in the context of normal/slightly elevated LDL cholesterol. Outcomes in treatment studies in or including diabetic patients suggest that a variety of therapies may be of benefit in reducing cardiovascular risk in patients with the metabolic syndrome, including physiologic therapies and pharmacologic treatments, such as aspirin, antihypertensive therapy, anti-ischemic therapy, and lipid-modifying therapies. The recently updated National Cholesterol Education Program Adult Treatment Panel III guidelines identify the metabolic syndrome as a secondary target of lipid-lowering therapy after LDL cholesterol reduction and recommend use of weight reduction and increased physical activity to address underlying risk factors as well as therapies to address specific lipid and nonlipid risk factors.

Referencia bibliográfica:
Am J Cardiol. 2003 Apr 3;91(7A):29E-39E.

Systemic inflammation adipose tissue tumor necrosis factor, and leptin expression

Autor: Salas-Salvado J, Bullo M, Garcia-Lorda P, Megias I.

Abstract:
OBJECTIVES: To explore the links between tumor necrosis factor alpha (TNFalpha) and leptin adipose tissue expression and low-grade systemic inflammation and to determine the relationship between inflammation and the degree of adiposity, the presence of type 2 diabetes, and other cardiovascular risk factors. RESEARCH METHODS AND PROCEDURES: Ninety-one women (BMI 19 to 65 kg/m(2)) were divided into tertiles of CRP. Insulin resistance was calculated using the HOMA method. Albumin, fibrinogen, C-reactive protein (CRP), interleukin-6, sTNFR1, sTNFR2, and leptin levels were measured in serum and plasma samples. TNFalpha and leptin expression were measured by reverse transcription-polymerase chain reaction in abdominal subcutaneous adipose tissue samples. RESULTS: CRP was positively related to BMI and upper distribution of adiposity. TNFalpha and leptin adipose tissue expression were higher in the upper tertile of CRP. Also, peripheral levels of both soluble TNFRs and leptin were higher in patients with the greatest inflammation degree. Diabetes, dislipidemia, and hypertension were most prevalent in patients in the upper CRP tertile. Inflammatory markers of diabetic women were significantly different from those of nondiabetic women, even after adjusting for differences in body fat. BMI, type 2 diabetes, and adipose TNFalpha mRNA levels were significant predictors of serum CRP levels (r(2) = 0.28, p < 0.001). DISCUSSION: These results are in agreement with the hypothesis that the synthesis of adipose tissue TNFalpha and leptin could induce the production of interleukin-6, CRP, and other acute-phase reactants, thus contributing to the maintenance of chronic low-grade inflammation state involved in the progression of obesity and its associated comorbidities.
Referencia bibliográfica:
Obes Res. 2003 Apr;11(4):525-31.

Assessing impact of weight on quality of life.

Autor:
Kolotkin RL, Head S, Hamilton M et al.

Abstract:
This paper is a preliminary report on the development of a new instrument, the Impact of Weight on Quality of Life (IWQOL) questionnaire, that assesses the effects of weight on various areas of life. We conducted two studies utilizing subjects in treatment for obesity at Duke University Diet and Fitness Center. The first study describes item development, assesses reliability, and compares pre- and post-treatment scores on the IWQOL. In the second study we examined the effects of body mass index (BMI), gender, and age on subjects' perceptions of impact of weight on quality of life. Results indicate adequate psychometric properties with test-retest reliabilities averaging .75 for single items, and .89 for scales. Scale internal consistency averaged .87. Post-treatment scores differed significantly from pre-treatment scores on all scales, indicating that treatment produced positive changes in impact of weight on quality of life. The results of the second study indicate that the impact of weight generally worsened as the patients' size increased. However for women there was no association between BMI and impact of weight on Self-Esteem and Sexual Life. Even at the lowest BMI tertile studied, women reported that weight had a substantial impact in these areas. There were also significant gender differences, with women showing greater impact of weight on Self-Esteem and Sexual Life compared with men. The impact of age was a bit surprising, with some areas showing positive changes and others showing no change.

Referencia bibliográfica:
Obes Res 1995 Jan;3(1):49-56.

A simple estimate of mortality attributable to excess weight

Autor:
Banegas JR, López-García E, Gutierrez-Fisac JL et al.

Abstract:
OBJECTIVE: To estimate the current burden of mortality attributable to excess weight in the European Union (EU). METHODS: Prevalence of overweight (body mass index, BMI 25-29.9 kg/m(2)) and obesity (BMI >or=30 kg/m(2)) were based on self-reported data from a survey with samples representative of the 15 EU Member States in 1997. Primary source of relative risk (RR) of death by BMI was the first American Cancer Prevention Study (CPS I). Additional calculations were performed to account for effect of smoking (using CPS I data for non- or never-smokers), for pre-existing illness (using the second CPS, CPS II, data for healthy never-smokers) and using RRs derived from European rather than US data (using data from a meta-analysis of prospective studies). Mortality attributable to excess weight was calculated by combining the prevalences of overweight and obesity, the RRs, and the number of deaths in the EU countries. RESULTS: Annual deaths attributable to overweight and obesity totalled approximately 279 000 when RRs for all subjects were used. When RRs for nonsmokers only were applied to the entire population, about 304 000 deaths were attributable to excess weight. In analyses using RRs which controlled for both smoking and history of disease, the number of deaths attributable to excess weight was estimated at about 337 000 based on European data and at about 401 000 based on US data. In the EU, therefore, a minimum of 279 000 deaths were attributable to excess weight (7.7% of all deaths, varying from 5.8% for France through 8.7% for the UK). More attributable deaths occurred among the obese (175 000) than among the overweight (104 000). Around 70% were cardiovascular disease deaths (195 000) and 20% cancer deaths (53 000). CONCLUSION: Mortality attributable to excess weight is a major public health problem in the EU. At least one in 13 annual deaths in the EU are likely to be related to excess weight.

Referencia bibliográfica:
Eur J Clin Nutr. 2003 Feb;57(2):201-8.

A prospective study of obesity risk of coronary heart disease in women.

Autor:
Manson JE, Colditz GA, Stampfer MJ, et al.

Abstract:
We examined the incidence of nonfatal and fatal coronary heart disease in relation to obesity in a prospective cohort study of 115,886 U.S. women who were 30 to 55 years of age in 1976 and free of diagnosed coronary disease, stroke, and cancer. During eight years of follow-up (775,430 person-years), we identified 605 first coronary events, including 306 nonfatal myocardial infarctions, 83 deaths due to coronary heart disease, and 216 cases of confirmed angina pectoris. A higher Quetelet index (weight in kilograms divided by the square of the height in meters) was positively associated with the occurrence of each category of coronary heart disease. For increasing levels of current Quetelet index (less than 21, 21 to less than 23, 23 to less than 25, 25 to less than 29, and greater than or equal to 29), the relative risks of nonfatal myocardial infarction and fatal coronary heart disease combined, as adjusted for age and cigarette smoking, were 1.0, 1.3, 1.3, 1.8, and 3.3 (Mantel-extension chi for trend = 7.29; P less than 0.00001). As expected, control for a history of hypertension, diabetes mellitus, and hypercholesterolemia--conditions known to be biologic effects of obesity--attenuated the strength of the association. The current Quetelet index was a more important determinant of coronary risk than that at the age of 18; an intervening weight gain increased risk substantially. These prospective data emphasize the importance of obesity as a determinant of coronary heart disease in women. After control for cigarette smoking, which is essential to assess the true effects of obesity, even mild-to-moderate overweight increased the risk of coronary disease in middle-aged women.

Referencia bibliográfica:
N Engl J Med. 1990 Mar 29;322(13):882-9.

Waist circunference action levels in the identification of cardiovascular risk factors: prevalence study in a random sample.

Autor:
Han TS, van Leer EM, Seidell JC and Lean MEJ

Abstract:
OBJECTIVE--To determine the frequency of cardiovascular risk factors in people categorised by previously defined "action levels" of waist circumference. DESIGN--Prevalence study in a random population sample. SETTING--Netherlands. SUBJECTS--2183 men and 2698 women aged 20-59 years selected at random from the civil registry of Amsterdam and Maastricht. MAIN OUTCOME MEASURES--Waist circumference, waist to hip ratio, body mass index (weight (kg)/height (m2)), total plasma cholesterol concentration, high density lipoprotein cholesterol concentration, blood pressure, age, and lifestyle. RESULTS--A waist circumference exceeding 94 cm in men and 80 cm in women correctly identified subjects with body mass index of > or = 25 and waist to hip ratios > or = 0.95 in men and > or = 0.80 in women with a sensitivity and specificity of > or = 96%. Men and women with at least one cardiovascular risk factor (total cholesterol > or = 6.5 mmol/l, high density lipoprotein cholesterol < or = 0.9 mmol/l, systolic blood pressure > or = 160 mm Hg, diastolic blood pressure > or = 95 mm Hg) were identified with sensitivities of 57% and 67% and specificities of 72% and 62% respectively. Compared with those with waist measurements below action levels, age and lifestyle adjusted odds ratios for having at least one risk factor were 2.2 (95% confidence interval 1.8 to 2.8) in men with a waist measurement of 94-102 cm and 1.6 (1.3 to 2.1) in women with a waist measurement of 80-88 cm. In men and women with larger waist measurements these age and lifestyle adjusted odds ratios were 4.6 (3.5 to 6.0) and 2.6 (2.0 to 3.2) respectively. CONCLUSIONS--Larger waist circumference identifies people at increased cardiovascular risks.

Referencia bibliográfica:
BMJ. 1995 Nov 25;311(7017):1401-5.

Leptin and its role in lipid metabolism.

Autor:
Hynes GR and Jones, PJH.

Abstract:
Since the discovery of leptin in 1994, a considerable amount of research has focused on leptin as a central regulator of body weight. In the animal model, research has demonstrated leptin action through hypothalamic centres altering both satiety and energy expenditure. In contrast to animal studies, it is unlikely that leptin functioning in the human system exerts such a profound role in body weight regulation. Human studies suggest that leptin levels are strongly correlated with both percentage fat mass and body mass index, in accordance with the proposed 'lipostatic theory'. Current research suggests the existence of a unique inter-relationship between dietary fat, leptin expression and leptin action within the peripheral system. More specifically, it has been demonstrated that polyunsaturated fatty acid (PUFA) intake influences adipose tissue expression of leptin, and of several lipogenic enzymes and transcription factors. In addition, leptin stimulates triglyceride depletion in white adipose tissue without increasing free fatty acid release, thus favouring fatty acids versus glucose as a fuel source. Recent studies suggest that the reduction in adipose hypertrophy observed with n-3 PUFA-containing fish oil feeding might involve a leptin-specific process. A large amount of evidence supports direct functioning of leptin in peripheral lipid metabolism in vivo and in vitro. It is possible that PUFAs will maintain an efficient level of circulating leptin, thus preventing leptin insensitivity and weight gain. There has been much recent progress in clinical leptin research, from energy expenditure to leptin analogue efficacy; the purpose of the present review is to summarize our current understanding of leptin functioning.

Referencia bibliográfica:
Curr Opin Lipidol. 2001 Jun;12(3):321-7.

Leptin increases uncoupling protein expression and energy expenditure.

Autor:
Scarpace PJ et al.

Abstract:
In ob/ob mice, leptin increases energy expenditure and sympathetic outflow to brown adipose tissue (BAT). To test whether the mechanism of increased energy expenditure may involve increased thermogenesis in BAT, we acclimated normal rats to thermoneutrality for 2 wk followed by leptin administration for 1 wk. Some rats were food restricted for 1 wk to the level of food consumption in the leptin-treated ad libitum-fed rats, and the same rats were both food restricted and administered leptin for a second week. We examined oxygen consumption and uncoupling protein (UCP) expression in BAT. Leptin increased oxygen consumption after the 5th and 6th days in ad libitum-fed rats and after the 4th, 5th, and 6th days in food-restricted rats. Leptin increased BAT UCP mRNA levels greater than twofold in both ad libitum-fed and food-restricted rats. These data demonstrate a leptin-induced increase in energy expenditure in nonmutant rodents and suggest that one mechanism by which leptin increases energy expenditure is through increased thermogenesis in BAT, including increased expression of UCP.

Referencia bibliográfica:
Am J Physiol. 1997 Jul;273(1 Pt 1):E226-30.

Polyunsaturated fatty acid regulation of gene expression.

Autor:
Ntambi JM, Bene H.

Abstract:
Polyunsaturated fatty acids (PUFAs), specifically the n-3 and n-6 series, play a key role in the progression or prevention of human diseases such as obesity, diabetes, cancer, neurological and heart disease, mainly by affecting cellular membrane lipid composition, metabolism, signal-transduction pathways, and by direct control of gene expression. PUFAs show regulation of gene expression in several tissues, including brain, liver, heart, and adipose. Most recently, research has focused on identifying the mechanisms by which PUFAs regulate lipogenic gene expression. Research to date indicates that PUFA-mediated regulation of the genetic expression and proteolytic maturation of a group of transcription factors termed sterol regulatory element binding proteins (SREBPs) accounts for the suppression of hepatic lipogenic gene expression. However, our recent studies on the transcriptional regulation of the stearoyl-coenzyme A (CoA) desaturase gene, encoding a key enzyme in the cellular synthesis of monounsaturated fatty acids from saturated fatty acids indicates that PUFA can suppress gene transcription by a mechanism independent of SREBP maturation.

Referencia bibliográfica:
J Mol Neurosci. 2001 Apr-Jun;16(2-3):273-8; discussion 279-84.

Directiva 96/8/ CE de 26 de Febrero.

Lessons from obesity management programmes: greater initial weight loss improves long-term maintenance.

Autor:
Astrup A and Rössner S.

Abstract:
It is a common belief that weight loss achieved at a slow rate is better preserved than if the weight is lost more rapidly. However, the literature shows that initial weight loss is positively, not negatively, related to long-term weight maintenance. There is evidence from randomised intervention trials to support that a greater initial weight loss induced without changes in lifestyle (e.g. liquid formula diets or anorectic drugs) improves long-term weight maintenance, providing it is followed by a 1-2 years integrated weight maintenance programme consisting of lifestyle interventions involving dietary change, nutritional education, behaviour therapy and increased physical activity. In conclusion, we find evidence to suggest that a greater initial weight loss as the first step of a weight management programme may result in improved sustained weight maintenance.

Referencia bibliográfica:
Obes Rev. 2000 May;1(1):17-9.

Very-low-calorie diets and sustained weight loss.

Autor:
Saris WHM.

Abstract:
OBJECTIVE: To review of the literature on the topic of very-low-calorie diets (VLCDs) and the long-term weight-maintenance success in the treatment of obesity. RESEARCH METHODS AND PROCEDURES: A literature search of the following keywords: VLCD, long-term weight maintenance, and dietary treatment of obesity. RESULTS: VLCDs and low-calorie diets with an average intake between 400 and 800 kcal do not differ in body weight loss. Nine randomized control trials, including VLCD treatment with long-term weight maintenance, show a large variation in the initial weight loss regain percentage, which ranged from -7% to 122% at the 1-year follow-up to 26% to 121% at the 5-year follow-up. There is evidence that a greater initial weight loss using VLCDs with an active follow-up weight-maintenance program, including behavior therapy, nutritional education and exercise, improves weight maintenance. CONCLUSIONS: VLCD with active follow-up treatment seems to be one of the better treatment modalities related to long-term weight-maintenance success.

Referencia bibliográfica:
Obes Res. 2001 Nov;9 Suppl 4:295S-301S.

Long term efficacy of dietary treatment of obesity: a systematic review of studies published between 1931 and 1999.

Autor:
Ayyad C and Andersen T.

Abstract:
METHODS: MEDLINE surveys were carried out and reference lists were cross-checked to identify publications on long-term outcome for dietary treatment of obesity. 898 papers were identified, 17 fulfilled our planned criteria for inclusion (dietary treatment; adults; follow-up period > or = 3 years; follow-up rate > or = 50% of original study group; information on one of the success criteria: maintenance of all weight initially lost (or further weight reduction) or maintenance of at least nine to 11 kg of initial weight loss; obesity complications of the patient group not over-represented; English, German or Scandinavian languages). RESULTS: The 17 included publications (here of three publications on randomized clinical trials with control group relevant for this review) reported on 21 study groups, comprising 3030 patients. Of these 2131 (70%) were followed-up for 3-14 years (median 5 years). Mean initial weight loss ranged from four to 28 kg (median 11 kg). Overall, 15% (median, range 0-49%) of followed-up patients fulfilled one of the criteria for success. Overall, success rates seemed stable for up to 14 years of observation. Diet combined with group therapy lead to better long-term success rates (median 27%) than did diet alone (median 15%) or diet combined with behaviour modification (median 14%). Active follow-up was generally associated with better success rates than was passive follow-up (19% vs. 10%). Conventional diet seemed to be most efficacious in addition with group therapy, whereas VLCD apparently was most efficacious if combined with behaviour modification and active follow-up. CONCLUSION: The literature on long-term follow-up of dietary treatment of obesity, although limited and inhomogeneous, points to an overall median success rate of 15% and a possible adjuvant effect of group therapy, behaviour modification and active follow-up.

Referencia bibliográfica:
Obes Rev. 2000 Oct;1(2):113-9.

Long-term weight-loss maintenance: a meta-analysis of US studies.

Autor:
Anderson JW, Konz EC, Frederich RC et al.

Abstract:
BACKGROUND: Current perception is that participants of a structured weight-loss program regain all of their weight loss within 5 y. OBJECTIVE: The objective was to examine the long-term weight-loss maintenance of individuals completing a structured weight-loss program. DESIGN: Studies were required to 1) have been conducted in the United States, 2) have included participants in a structured weight-loss program, 3) have provided follow-up data with variance estimates for > or =2 y. Primary outcome variables were weight-loss maintenance in kilograms, weight-loss maintenance as a percentage of initial weight loss, and weight loss as a percentage of initial body weight (reduced weight). RESULTS: Twenty-nine studies met the inclusion criteria. Successful very-low-energy diets (VLEDs) were associated with significantly greater weight-loss maintenance than were successful hypoenergetic balanced diets (HBDs) at all years of follow-up. The percentage of individuals at 4 or 5 y of follow-up for VLEDs and HBDs were 55.4% and 79.7%, respectively. The results for VLEDs and HBDs, respectively, were as follows: weight-loss maintenance, 7.1 kg (95% CI: 6.1, 8.1 kg) and 2.0 (1.5, 2.5) kg; percentage weight-loss maintenance, 29% (25%, 33%) and 17% (13%, 22%); and reduced weight, 6.6% (5.7%, 7.5%) and 2.1% (1.6%, 2.7%). Weight-loss maintenance did not differ significantly between women and men. Six studies reported that groups who exercised more had significantly greater weight-loss maintenance than did those who exercised less. CONCLUSIONS: Five years after completing structured weight-loss programs, the average individual maintained a weight loss of >3 kg and a reduced weight of >3% of initial body weight. After VLEDs or weight loss of > or =20 kg, individuals maintained significantly more weight loss than after HBDs or weight losses of <10 kg.

Referencia bibliográfica:
Am J Clin Nutr. 2001 Nov;74(5):579-84.

Fish oil (n-3) polyunsaturated fatty acids beneficially affect biliary cholesterol nucleation time in obese women losing weight.

Autor:
Mendez-Sanchez N, Gonzalez V, Aguayo P et al.

Abstract:
It has been reported that intake of (n-3) polyunsaturated fatty acids (PUFA) reduces the risk of coronary heart disease and decreases biliary cholesterol saturation in the bile of gallstone patients. We investigated the effect of n-3 PUFA on cholesterol saturation index (CSI) and nucleation time (NT) in obese subjects who were losing weight. This was a double-blind, placebo-controlled clinical trial. Obese women (n = 35) with a body mass index (BMI) > or = 30 kg/m(2), with no prior history of gallstones or cholecystectomy by ultrasound were first studied to ensure absence of stones or biliary sludge. The women were then assigned to a hypocaloric regimen [5.02 MJ (1200 kcal)/d] and to receive 1200 mg/d of ursodeoxycholic acid (UDCA), 11.3 g/d of (n-3) PUFA or a placebo for 6 wk. BMI, CSI and NT were recorded at baseline and at the end of the experimental period. BMI decreased 5.75 +/- 2.7%/mo (range, 1.5-12.42%/mo) during the experiment. The CSI did not change in any of the groups. Cholesterol NT decreased significantly in the UDCA and placebo groups, but not in the (n-3) PUFA group. None of the women had developed gallstones at 6 wk. These results suggest that (n-3) PUFA maintain the CSI and NT in obese women during rapid weight loss, which probably results in the prevention of cholesterol gallstone formation.

Referencia bibliográfica:
J Nutr. 2001 Sep;131(9):2300-3.

The associations of a marine diet with plasma lipids, blood glucose, blood pressure and obesity among the inuit in Greenland.

Autor:
Bjerregaard P, Pedersen HS, Mulvad G.

Abstract:
OBJECTIVE: To analyse the associations between the intake of fish and marine mammals and risk factors for cardiovascular disease, ie lipid profile, fasting blood glucose, blood pressure and obesity, in a population whose average consumption of n-3 fatty acids is high compared with Western countries. DESIGN: Information was obtained from a population survey in Greenland: interview data, clinical data and fasting blood samples were obtained from a random sample of Inuit from three towns and four villages. SUBJECTS: Two-hundred and fifty-nine adult Inuit (74% of the sample). RESULTS: Marine diet was positively associated with serum high-density lipoprotein (HDL) and blood glucose and inversely with very-low-density lipoprotein (VLDL) and triglyceride. Association with low-density lipoprotein (LDL), diastolic and systolic blood pressure, waist-hip ratio and body mass index were inconsistent and not statistically significant. The pattern was similar within groups with low, medium and high consumption of marine food. CONCLUSIONS: There are statistically significant associations between the consumption of marine food and certain lipid fractions in the blood also in this population with a very high average intake of marine food. The observation that blood glucose is positively associated with marine diet in a population survey is new and should be repeated. There was good agreement between the results for the reported consumption of seal and those for the biomarkers. SPONSORSHIP: The study was financially supported by the Greenland Home Rule, Directorate of Health and Research, the Commission for Scientific Research in Greenland, and the Danish Medical Research Council.

Referencia bibliográfica:
Eur J Clin Nutr. 2000 Sep;54(9):732-7.

Modificaciones antropométricas y balance de nitrógeno en pacientes con obesidad mórbida tratados con dieta muy baja en calorías.

Autor:
Formiguera Sala, X et al.

Abstract:
BACKGROUND: Morbid obesity is associated with increased morbidity and mortality. In these patients, weight reduction reduces associated morbidity and increases life expectancy. The aim of the present study was to evaluate the anthropometric changes in a group of patients treated with a very low caloric diet and to assess nitrogen balance and clinical and biological tolerance. METHODS: Overall 65 patients were prospectively evaluated (12 males and 53 females with a mean age of 45 +/- 7 years. Mean initial weight was 110 +/- 21 kg, with a Quetelet index of 43 +/- 7 kg/m2. They were treated as inpatients during 42 days exclusively with a very low caloric diet. They also followed a physical exercise program during one hour daily. RESULTS: The weight reduction was 15 +/- 4 kg (p less than 0.0001) with a reduction in fat mass of 9 +/- 2 kg (p less than 0.0001) and a reduction in fat-free mass of 6 +/- 3 kg (p less than 0.0001). The Quetelet index was reduced in 5 +/- 1 points (p less than 0.0001). There was also a reduction in the muscle adipose index from 1 +/- 0.2 to 0.7 +/- 0.2. The nitrogen balance remained negative throughout the 42 study days, although with a clear trend towards equilibrium. There were significant reductions in blood glucose, proteinemia, total cholesterol and subfractions. Triglycerides did not show significant changes. Clinical tolerance was excellent in all cases except 4 who withdraw from treatment because of nausea and vomiting. CONCLUSIONS: In this study, very low caloric diet achieved satisfactory weight reduction, basically at the expense of adipose tissue, reflected in a reduction of the muscle adipose index. Nitrogen balance remained negative throughout the treatment but with a trend towards normalization. Tolerance was excellent in 61 of the 65 cases (94%).

Revisión bibliográfica:
Med Clin (Barc). 1991 Mar 23;96(11):401-4.