CLOCK gene is implicated in weight reduction in obese patients participating in a dietary programme based on the Mediterranean diet.

INTRODUCTION: The success of obesity therapy is dependent on the genetic background of the patient. Circadian Locomotor Output Cycles Kaput (CLOCK), one of the transcription factors from the positive limb of the molecular clock, is involved in metabolic alterations. OBJECTIVE: To investigate whether five candidate polymorphisms from CLOCK were associated with anthropometric, metabolic measures and weight loss in response to a behavioural weight reduction programme based on the Mediterranean diet. METHODS: Five hundred overweight/obese subjects, aged 20-65 years, who attended outpatient clinics specializing in obesity, were studied. Anthropometric, biochemical and dietary intake variables were analysed. Effectiveness of the programme and weight loss progression during 28 weeks of treatment was assessed. RESULTS: Four of five CLOCK SNPs selected were significantly associated with obesity variables (P<0.05). The genetic variation in the rs1801260 CLOCK was associated with obesity at baseline and also affected weight loss. Patients with the variant allele (G) lost significantly less weight i(P=0.008) compared with wild type. Repeated measures analysis showed that weight loss over time was significantly different between rs1801260 CLOCK variations (P=0.038). Carriers of the G allele displayed greater difficulty in losing weight than non-carriers. In this particular polymorphism, the frequency of short-time sleepers (< or =6 h per day) was greater in minor allele carriers than in non-carriers (59% vs 41%; P<0.05). CLOCK polymorphisms were also associated with significant differences in total plasma cholesterol at the completion of dietary treatment (P<0.05). CONCLUSIONS: We have replicated previous studies showing a relationship between CLOCK gene polymorphisms and obesity. CLOCK rs1801260 SNP may predict the outcome of body weight reduction strategies based on low-energy diets.

Is soft drink consumption associated with body composition? A cross-sectional study in Spanish adolescents.

OBJECTIVES: Published data about the association between the consumption of sweetened soft-drinks (SSD) and obesity in childhood are controversial and still inconsistent. In addition, data are lacking in the Spanish population. The purpose of this study was therefore, to explore the cross-sectional association between body composition-related parameters and SSD consumption in Spanish adolescents. SUBJECTS AND METHODS: A representative sample of 1,523 adolescents (768 boys and 755 girls), with complete dietary data as well as anthropometric measurements, were included in this study. Weight, height, waist circumferences, and 6 skinfolds were measured, and BMI and percentage body fat were calculated. From a 24h dietary recall the subjects were grouped in 3 groups according to their SSD consumption: 1) Non-consumers (0 g of SSD consumption); 2) Moderate consumption (< 336 g/day of SSD, equivalent to the average SSD portion size); and 3) High consumption (> 336 g/day of SSD). RESULTS: 67% males and 75% females did not consume any SSD the day before the dietary recall interview. Males consumed more SSD than females. Regarding the association between SSD consumption and measures of obesity, no difference was observed between the three groups of SSD consumption in any of the anthropometric measurement, BMI or body fat. CONCLUSION: As no association was present between SSD consumption and obesity in our cross-sectional study we suggest that dietary patterns and habits as well as lifestyle factors such as physical activity should be present when examining cross-sectional or longitudinal relationships with obesity. Multidisciplinary intervention studies are crucial when trying to develop solutions against the increasing obesity epidemic.

Body fat distribution in pre-and post-menopausal women: metabolic and anthropometric variables.

BACKGROUND: Abdominal obesity is associated with coronary risk although the causality is not well established. OBJECTIVE: To compare body fat distribution and metabolic variables in obese pre- and post- menopausal women. DESIGN: The study was conducted in 55 obese female subjects (22 pre- and 33 post- menopausal) with body mass indices (BMI) from 27 to 35 Kg/m2. Body fat distribution was measured using waist and hip circumference and computerized tomography. Hormones such as estradiol, testosterone, androstenedione, dehydroepiandrosterone-sulfate, as well as plasma lipids such as triglycerides, total cholesterol, high density lipoprotein, low density lipoprotein, apoproteins A and B, were also determined. RESULTS: No significant differences were found between the two groups in BMI, percentage of body fat, waist circumference, triceps, biceps, suprailiac and abdominal skinfolds. Hip circumference, subscapular skinfold and subcutaneous abdominal adipose tissue area were significantly lower, and waist-hip ratio, visceral area and visceral to subcutaneous area ratios significantly higher in post- menopausal women (P < 0.05). As was expected, basal plasma estrogens, and dehydroepiandrosterone-sulfate, were significantly higher in pre-menopausal women. When comparing plasma lipids, blood cholesterol and low density lipoprotein, values were significantly higher in the post-menopausal group (P < 0.05). CONCLUSIONS: Our data suggest that body fat distribution changes according to menopausal status, with central obesity more pronounced in post- menopausal women. Metabolic abnormalities are related more to visceral adipose tissue and estrogen plasma levels than to BMI.