Ghrelin, Sleep Reduction and Evening Preference: Relationships to CLOCK 3111 T/C SNP and Weight Loss

Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, eating patterns and chronobiological characteristics) and hormonal (plasma ghrelin and leptin concentrations) factors which could explain the previously reported association between the CLOCK 3111T/C SNP and weight loss.We recruited 1495 overweight/obese subjects (BMI: 25-40 kg/m(2)) of 20-65 y. who attended outpatient obesity clinics in Murcia, in southeastern Spain. We detected an association between the CLOCK 3111T/C SNP and weight loss, which was particularly evident after 12-14 weeks of treatment (P = 0.038). Specifically, carriers of the minor C allele were more resistant to weight loss than TT individuals (Mean±SEM) (8.71±0.59 kg vs 10.4±0.57 kg) C and TT respectively. In addition, our data show that minor C allele carriers had: 1. shorter sleep duration Mean ± SEM (7.0±0.05 vs 7.3±0.05) C and TT respectively (P = 0.039), 2. higher plasma ghrelin concentrations Mean ± SEM (pg/ml) (1108±49 vs 976±47)(P = 0.034); 3. delayed breakfast time; 4. evening preference and 5. less compliance with a Mediterranean Diet pattern, as compared with TT homozygotes.Sleep reduction, changes in ghrelin values, alterations of eating behaviors and evening preference that characterized CLOCK 3111C carriers could be affecting weight loss. Our results support the hypothesis that the influence of the CLOCK gene may extend to a broad range of variables linked with human behaviors

Dietary Intervention and Nutritional Counseling

The dietary treatment for weight loss in overweight and obesity has been approached in many different dietary models. Nevertheless, beside the size of weight loss, the main outcomes should be mostly the improvement of body composition (loss of body fat and preservation of lean body mass), long-term maintenance, nutritional quality of the diet, lower risk for chronic diseases (better metabolic parameters), improvement in quality of life and psychological well-being. The most popular diets have been analyzed: High protein diets (HPD); Low-carbohydrate diets (LChoD) and Low Glycaemic Index or Load diets (LGID); Low-Fat diets (LFD); Low Calorie Diet (LCD) and Very low-calorie diet (VLCD); Ketogenic diets (KD). In the end, the criteria for the development of a balanced dietary treatment in obese patient are discussed as a result of a critical analysis of the different dietary patterns described. Several evidences lead to the conclusion that the Mediterranean dietary pattern better respects the clinical guidelines for overweight and obesity treatment. In order to achieve a good compliance and the subsequently long-term results, the multidisciplinary approach, based on nutritional counseling, physical activity, together with the cognitive-behavioral therapy, is the only reasonable therapeutic option