Showing papers by "Arne Astrup published in 2006"

Effect of weight reduction in obese patients diagnosed with knee osteoarthritis: a systematic review and meta-analysis.

Abstract: This review aims to assess by meta‐analysis of randomised controlled trials (RCTs) changes in pain and function when overweight patients with knee osteoarthritis (OA) achieve a weight loss. Systematic searches were performed and reference lists from the retrieved trials were searched. RCTs were enclosed in the systematic review if they explicitly stated diagnosis of knee OA and reported a weight change as the only difference in intervention from the control group. Outcome Measures for Arthritis Clinical Trials III outcome variables were considered for analysis. Effect size (ES) was calculated using RevMan, and meta‐regression analyses were performed using weighted estimates from the random effects analyses. Among 35 potential trials identified, four RCTs including five intervention/control groups met our inclusion criteria and provided data from 454 patients. Pooled ES for pain and physical disability were 0.20 (95% CI 0 to 0.39) and 0.23 (0.04 to 0.42) at a weight reduction of 6.1 kg (4.7 to 7.6 kg). Meta‐regression analysis showed that disability could be significantly improved when weight was reduced over 5.1%, or at the rate of >0.24% reduction per week. Clinical efficacy on pain reduction was present, although not predictable after weight loss. Meta‐regression analysis indicated that physical disability of patients with knee OA and overweight diminished after a moderate weight reduction regime. The analysis supported that a weight loss of >5% should be achieved within a 20‐week period—that is, 0.25% per week.

High levels of industrially produced trans fat in popular fast foods.

Abstract: To the Editor: The daily intake of about 5 g of trans fat is associated with a 25 percent increase in the risk of ischemic heart disease.1 For this reason, it is recommended that the consumption of trans fat be as low as possible.2 We determined the content of industrially produced trans fatty acids in 43 servings of fast foods bought in 20 countries between November 2004 and September 2005. We and our colleagues decided which cities to include in the study on the basis of planned visits for other purposes. The foods (chicken nuggets and french fries) were purchased . . .

Randomized, multi-center trial of two hypo-energetic diets in obese subjects: high- versus low-fat content

Abstract: Subjects: Obese (BMI X30 kg/m 2 ) adult subjects (n ¼ 771), from eight European centers. Measurements: Body weight loss, dropout rates, proportion of subjects who lost more than 10% of initial body weight, blood lipid profile, insulin and glucose. Results: The dietary fat energy percent was 25% in the low-fat group and 40% in the high-fat group (mean difference: 16 (95% confidence interval (CI) 15–17)%). Average weight loss was 6.9 kg in the low-fat group and 6.6 kg in the high-fat group (mean difference: 0.3 (95% CI � 0.2 to 0.8) kg). Dropout was 13.6% (n ¼ 53) in the low-fat group and 18.3% (n ¼ 70) in the high-fat group (P ¼ 0.001). Among completers, more subjects lost 410% in the low-fat group than in the high-fat group ((20.8%, n ¼ 70) versus (14.7%, n ¼ 46), P ¼ 0.02). Fasting plasma total, low-density lipoprotein- and high-density lipoprotein-cholesterol decreased in both groups, but more so in the low-fat group than in the high-fat group. Fasting plasma insulin and glucose were lowered equally by both diets. Conclusions: The low-fat diet produced similar mean weight loss as the high-fat diet, but resulted in more subjects losing 410% of initial body weight and fewer dropouts. Both diets produced favorable changes in fasting blood lipids, insulin and glucose.

Genetic Polymorphisms and Weight Loss in Obesity: A Randomised Trial of Hypo-Energetic High- versus Low-Fat Diets

Abstract: OBJECTIVES: To study if genes with common single nucleotide polymorphisms (SNPs) associated with obesity-related phenotypes influence weight loss (WL) in obese individuals treated by a hypo-energetic low-fat or high-fat diet. DESIGN: Randomised, parallel, two-arm, open-label multi-centre trial. SETTING: Eight clinical centres in seven European countries. PARTICIPANTS: 771 obese adult individuals. INTERVENTIONS: 10-wk dietary intervention to hypo-energetic (-600 kcal/d) diets with a targeted fat energy of 20%-25% or 40%-45%, completed in 648 participants. OUTCOME MEASURES: WL during the 10 wk in relation to genotypes of 42 SNPs in 26 candidate genes, probably associated with hypothalamic regulation of appetite, efficiency of energy expenditure, regulation of adipocyte differentiation and function, lipid and glucose metabolism, or production of adipocytokines, determined in 642 participants. RESULTS: Compared with the noncarriers of each of the SNPs, and after adjusting for gender, age, baseline weight and centre, heterozygotes showed WL differences that ranged from -0.6 to 0.8 kg, and homozygotes, from -0.7 to 3.1 kg. Genotype-dependent additional WL on low-fat diet ranged from 1.9 to -1.6 kg in heterozygotes, and from 3.8 kg to -2.1 kg in homozygotes relative to the noncarriers. Considering the multiple testing conducted, none of the associations was statistically significant. CONCLUSIONS: Polymorphisms in a panel of obesity-related candidate genes play a minor role, if any, in modulating weight changes induced by a moderate hypo-energetic low-fat or high-fat diet.

Fat oxidation before and after a high fat load in the obese insulin-resistant state

Abstract: Background: Obesity may be associated with a lowered use of fat as a fuel, which may contribute to the enlarged adipose tissue stores. Aim: The aim of the present study was to study fatty acid use in the fasting state and in response to a high fat load in a large cohort of obese subjects (n = 701) and a lean reference group (n = 113). Methods: Subjects from eight European centers underwent a test meal challenge containing 95 en% fat [energy content 50% of estimated resting energy expenditure (EE)]. Fasting and postprandial fat oxidation and circulating metabolites and hormones were determined over a 3-h period. Results: Postprandial fat oxidation (as percent of postprandial EE, adjusted for fat mass, age, gender, center, and energy content of the meal) decreased with increasing body mass index (BMI) category (P < 0.01), an effect present only in those obese subjects with a relatively low fasting fat oxidation (below median, interaction BMI category × fasting fat oxidation, P < 0.001). Fasting fat oxidatio...

Drug treatment of obesity

Abstract: Acceptable adverse effects and a clinical relevant weight loss of 3 to 5 kilograms have been found in long-term randomized clinical trials for sibutramine (Reductil) and orlistat (Xenical); these drugs may be prescribed for treatment of obesity for a duration of one and four years, respectively. This also seems to be the case for rimonabant (Acomplia), which is expected to receive approval in 2005 or 2006. However, until data on morbidity and mortality are available from RCTs, there is no absolute indication for prescribing drugs for treatment of obesity.

Genotype-by-nutrient interactions assessed in European obese women. A case-only study.

Abstract: BACKGROUND: The development of obesity is influenced by both genetic and environmental risk factors. Whereas changes in the environment appear to be responsible for the increasing prevalence of obesity, genetic factors interacting with environmental factors would contribute to explain obesity onset and severity. AIM: To explore epidemiologic genotype-by-nutrient interactions in obesity. METHODS: A total of 42 polymorphisms of 26 candidate genes for obesity were genotyped in 549 adult obese women recruited from eight European centres in a case-only study. The nutritional variables assessed in this study were the dietary fibre intake (grams per day), the ratio of dietary polyunsaturated fat to saturated fat (P:S ratio) and the percentage of energy derived from fat in the diet as calculated from a weighed three-day food record (%E). Under the assumption of genotype-nutrient independence in the population, the odds ratio calculated in a sample of obese women would indicate the existence of genotype-by-nutrient interactions, measured as deviations from the multiplicative effects of the genetic and the nutrient factors separately. RESULTS: No new but confirmaty evidences for genotype-by-nutrient interactions in obesity were detected in this case-only study. The test of interaction between fibre intake and the -514 C > T polymorphism of the hepatic lipase gene (LIPC) yielded P-values of 0.01 across different statistical models. Likewise, the -11377G > C polymorphism of the adiponectin gene (ADIPOQ) and the -681 C > G polymorphism of the PPARG3 gene might interact with the percentage of energy derived from fat in the diet for the development of obesity (P-values in the range of 0.01-0.05 across different statistical models). The P-values were not adjusted for multiple testing, so these results should be considered with caution. CONCLUSIONS: Although the use of obese-only samples is theoretically a useful approach to detect interactions, few genotype-by-nutrient interactions have been suggested in obese European women after the analysis of candidate polymorphisms and the selected nutrient variables. The most remarkable multiplicative interaction found in this study refers to the combination of the hepatic lipase gene polymorphism -514 C > T and fibre intake.

Consumer protection through a legislative ban on industrially produced trans fatty acids in foods in Denmark

Abstract: Legislation has, within a few years, virtually eliminated the intake of industrially produced trans fatty acids (IP-TFA) in Denmark, by banning any food with an IP-TFA content greater than 2% of total fat. This accomplishment has been obtained without noticeable effects on the availability, price or quality of foods previously containing high amounts of IP-TFA. Various public health organizations, including the World Health Organization, have recommended reducing the consumption of IP-TFA, and efforts have been made in several countries to comply, through the mandatory TFA labelling of prepackaged food, societal pressure and industrial initiatives to lower the content of IP-TFA in foods. Yet still, high concentrations of IP-TFA are found in popular foods in several countries including Norway and Sweden. This indicates that millions of people currently have intakes of IP-TFA that increase their risk of coronary heart disease. The Danish experience demonstrates that this risk can be eliminated. Keywords: fast food; labelling; legislation; recommendations; regulation; snack; trans fatty acids

Possible role of adiponectin and insulin sensitivity in mediating the favorable effects of lower body fat mass on blood lipids.

Abstract: Aims: The objective of this study was to investigate the role of insulin sensitivity and serum adiponectin concentration as determinants, in middle-aged men, of the relationship between lower body fat and blood lipids after truncal fat has been accounted for. Methods: Men (443) aged 39–65 yr, body mass index 18–43 kg/m 2 , participated in the study. The following variables were measured: regional body fat distribution as assessed by dual-energy x-ray absorptiometry, maximal oxygen uptake, physical activity, fasting levels of serum adiponectin, triglycerides, and high-density lipoproteinand total cholesterol. Plasma glucose and serum insulin were measured in the fasting state and after an oral glucose load. Results: Lower body fat mass was inversely associated with serum triglycerides and total cholesterol and positively with serum highdensity lipoprotein-cholesterol after adjustment for age, lean tissue mass, truncal fat mass, weight history, maximal oxygen uptake, and thelevelofphysicalactivity(P0.0005).Serumadiponectinleveland Matsudas insulin sensitivity index were positively intercorrelated, and both were positively correlated to lower body fat mass. When including adiponectin and insulin sensitivity in the analyses, the relationships between lower body fat mass and serum lipids were partly explained. Conclusion: For a given level of truncal fat mass, a large lower body fat mass is associated with an advantageous blood lipid profile, which may be partially mediated by the relationships to both insulin sensitivity and serum adiponectin level. (J Clin Endocrinol Metab 91: 1698–1704, 2006)

Food for thought or thought for food?--a stakeholder dialogue around the role of the snacking industry in addressing the obesity epidemic.

Abstract: The current obesity epidemic is generally considered multi-causal. Certain foods, including snacks such as potato chips, and their marketing are often highlighted as needing particular attention. This forces potato chip producers to take position on their role and responsibility. Based on expert interviews and a literature review, a systems analysis approach is presented that distinguishes between basic physiology, self-control and what we call jam transmitters, signals and pressures from the environment that hinder or frustrate self-control. Examples of the latter are commercial push and seduction, obesogenic cultures, obesogenic physical environment, socioeconomic factors, genes, hormones and instincts. Solution of the epidemic demands an approach that involves all factors and all related actors. As for the snacking industry, the comprehensive responses are: to introduce specific diet products; to improve the nutritional quality of its products; the latter combined with supporting and engaging in healthy lifestyle marketing; to practice responsible targeting of marketing; and to limit the promotion of unhealthy consumption patterns.

Low glycemic index diets and body weight

Abstract: In their review (low-glycaemic index diets and body weight regulation (2006)), McMillan-Price and Brand-Miller argue that the low glycemic index (GI) diet is a simple and more popular diet that will successfully improve cardiovascular risk factors and reduce body weight. We do not find that there is convincing evidence in the existing literature to suggest that a low GI diet is superior in achieving improvement in cardiovascular health and in reducing body weight in healthy overweight subjects, when compared to official dietary advice recommending a diet high in vegetables, fruit and fiber, and low in sugar and fat. This lack of evidence might partly be due to the lack of long-term, well-powered studies, with well-controlled diets differing only in GI. Data also suggest that subjects’ insulin sensitivity might be an important predictor of the effects of a low GI diet, and therefore findings from studies in insulin-resistant and diabetic subjects should not be extrapolated to findings in healthy individuals. We agree with McMillan-Price and Brand-Miller when they state that ‘in practice it is difficult to tease out the separate effects of GI, palatability, volume, fiber and other factors that influence satiety responses to realistic meals’. Predicting GI of realistic meals has also proven difficult. We therefore find that future studies should focus on individual food factors, such as the effect of whole grain, including intact grains, fiber, including resistant starch, energy density and preparation methods. This approach would allow for more tightly controlled trials, with less confounding factors, and also lead to simpler dietary advice with assured efficacy.

Subnormal energy expenditure: a putative causal factor in the weight gain induced by treatment of hyperthyroidism.

Abstract: Aims: To examine the causes of weight gain occurring as an adverse effect of treatment of hyperthyroidism. Methods: We measured 24-h energy expenditure (EE), body composition and spontaneous physical activity (SPA) in eight patients before and 1 year after treatment of hyperthyroidism was initiated, and eight controls. Results: One year after initiation of treatment thyrotropin was normalized, thyroid hormones had fallen to the lower end of the reference range and fat mass had increased by 3.5 kg (p < 0.001). Twenty-four hour EE adjusted for fat-free mass (FFM) was 15% higher in hyperthyroid patients before treatment than in controls (p = 0.003), and treatment decreased 24-h EE by 1.9 MJ/day (p = 0.001). After treatment, 24-h EE, adjusted for FFM, was similar to the controls. Multiple regression analyses showed that the suppressed EE could partly be attributed to an iatrogenic suppression of thyroid hormones, resulting in lower sleeping EE. Twenty-four hour SPA was normal in the hyperthyroid state, but decreased after treatment by 21% (p = 0.045), to a level not significantly different, but still below that of the controls. Conclusions: The study suggests that weight gain during treatment of hyperthyroidism might be due to subnormal levels of EE and SPA caused by a suppression of the thyroid hormone to a level in the lower end of the normal range.

Measurements of body composition by dual-energy X-ray absorptiometry improve prediction of energy expenditure.

Abstract: The prediction of energy expenditure by dual-energy X-ray absorptiometry (DXA) and bioimpedance analysis (BIA) was assessed in 35 healthy individuals of both sexes, with a mean body mass index (BMI) of 23.8 kg/m2 (range 18–33.8), and mean age of 30 years (22–40). Energy expenditure (EE) was measured under standard conditions in a respiration chamber, the total and regional body composition by DXA, and total body composition by BIA. When body composition was measured by BIA, 88.5% of the variation in 24-h EE was explained by lean body mass (LBM); this figure was increased by DXA, where total lean tissue mass (LTM) and total fat tissue mass (FTM) could account for 91.5% of the variation. Also, the prediction of resting energy expenditure (REE) was improved by DXA, from 88.1% to 89.8% (LBM vs. LTM, FTM). Measurements of regional body composition showed that trunk LTM was significantly superior as a predictor, especially of REE and sleeping EE (EE sleep), compared to the peripheral LTM; thus, the predictions of REE were 83% vs. 87% (peripheral vs. trunk), respectively; and the predictions of EE sleep were 83% vs. 89% (peripheral vs. trunk), respectively. Therefore, body composition measurements by DXA improved the prediction of EE. Trunk LTM was a superior predictor, especially of REE and EE sleep, compared to peripheral LTM. In conclusion, the present results suggest that measuring total and regional body composition by DXA can somewhat improve the prediction of EE.

How to Maintain a Healthy Body Weight

Abstract: The epidemic of both obesity and type 2 diabetes is due to environmental factors, but the individuals developing the conditions possess a strong genetic predisposition. Observational surveys and intervention studies have shown that excess body fatness is the major environmental cause of type 2 diabetes, and that even a minor weight loss can prevent its development in high-risk subjects. Maintenance of a healthy body weight in susceptible individuals requires 45-60 minutes physical activity daily, a fat-reduced diet with plenty of fruit, vegetables, whole grain, and lean meat and dairy products, and moderate consumption of calorie containing beverages. The use of table values to predict the glycemic index of meals is of little--if any--value, and the role of a low-glycemic index diet for body weight control is controversial. The replacement of starchy carbohydrates with protein from lean meat and lean dairy products enhances satiety, and facilitate weight control. It is possible that dairy calcium also promotes weight loss, although the mechanism of action remains unclear. A weight loss of 5-10% can be induced in almost all obese patients providing treatment is offered by a professional team consisting of a physician and dietitians or nurses trained to focus on weight loss and maintenance. Whereas increasing daily physical activity and regular exercise does not significantly effect the rate of weight loss in the induction phase, it plays an important role in the weight maintenance phase due to an impact on daily energy expenditure and also to a direct enhancement of insulin sensitivity.

Carbohydrates as macronutrients in relation to protein and fat for body weight control

Abstract: There is a need to explore how to increase the satiating power of the diet, so that people feel full with less energy, and by this means reduce their spontaneous energy intake. A reduction of dietary fat from typically 37–27% of total calories will produce a weight loss of 3–5 kg over 6 months, depending on the amount and source of carbohydrate and protein in the diet. The weight loss is sustained as long as the diet composition is adhered to, and evidence from the large Women's Health Initiative dietary intervention trial showed that those who complied with the fat reduction without any energy restriction maintained a lower body weight over 9 years than those on a normal fat diet. The predominant mechanism for the weight loss effect is the lower energy density of the fat-reduced diet, so that this diet provides more food volume and weight for less energy, and hence greater satiating effect than a higher-fat diet. It is likely that the diet also provides a metabolic advantage in individuals susceptible to obesity by a genetically determined impaired ability to rapidly adjust fat oxidation in response to increasing the dietary fat content. The carbohydrate source is also important for the diet's effect on body weight, that is, whereas sugars in solid foods seem to have the same satiating effect than starch, sugar in drinks seems to exert a low inhibition of subsequent food intake. Newer research indicates that increasing the protein content at the expense of fat and carbohydrate might offer a way to increase the satiating and thermogenic effect of ad lib diets, and facilitate weight loss and maintenance.

Alternative causes of obesity

Abstract: The prevailing understanding of the causes of obesity is based on the disturbance of the thermodynamic law of energy balance, primarily through increased intake or decreased expenditure of energy. Alternative causes of obesity, which still respect the law but also allow for primary fat accumulation, are: virus infection of fat cells, energy supply from bacterial fermentation of indigestible food components, psychosocial factors mediated by psychoneuroendocrine pathways, sleeplessness or poor quality of sleep and early life programming, in addition to the well-known and proven genetic programming.

[High levels of industrially produced trans fatty acids in popular fast food - but not in Denmark--secondary publication].

Abstract: An intake of trans-fatty acids of 5 grams per day is associated with an increase of 25% in the risk of ischemic heart disease. In 2004 Denmark, as the first country in the world, introduced a limitation on the content of industrially produced trans-fatty acids in foods. The amount in a "high-trans menu" consisting of popular foods was, from 2001 to 2005, reduced in Denmark from 30 g to <1 g. The amount in the same menu bought in countries within and outside the European Union is 20-40 g. During a period of just a few years, Denmark has thus eliminated a risk factor for ischemic heart disease without noticeable side effects for consumers. This risk factor is, however, still present in many other countries.

The importance of physical activity and fitness in avoiding the complications of obesity

Abstract: We have reviewed whether the complications of obesity can be attributed to low levels of physical activity and fitness, or if fatness per se has adverse effects on health. In both observational and interventional studies, fatness and inactivity seem to be independent risk factors. Abdominal obesity is a predictor of cardiovascular disease, which is independent of low fitness level, and obesity affects other risk factors adversely than inactivity does. However, physical activity does reduce the risk of type 2 diabetes and heart disease. It is concluded that both inactivity and obesity have an adverse effect on health.