Effects of Flavanol-rich Dark Chocolate Consumption on Metabolic Profiles Among Obese Adults Using Metabolomics Approach

Overview

Obesity has become a global issue due to its alarming high and increasing prevalence worldwide and the roles it plays in occurrence of many chronic diseases. In addition, obesity is characterized as a state of chronic, low-grade inflammation and is associated with an abnormal inflammatory response, low antioxidant capacity and reduced insulin sensitivity which lead to the generation of inflammation, oxidative stress and insulin resistance. As in Malaysia, study by National Health and Morbidity Survey Malaysia (NHMS) in 2011 and 2015 showed a continuing increase of the problem. In response to the rise of obesity prevalence, various efforts and strategies have been implemented in the past decade to combat this problem. The use of natural products as therapeutic agents in preventing metabolic disease has becoming popular. Cocoa and its products is a largely consumed food in the world. It has a very rich sources of phenolic compound. Several in vitro and in vivo studies have shown that polyphenols, with antioxidant, anti-inflammatory and anti-obesity properties, can boost energy expenditure and thermogenesis, lessen oxidative stress and inflammation while supporting weight loss management. Furthermore, the contribution of human studies especially among obese relatively limited. The popularity of chocolate and/or cocoa and its frequent consumption made it the target of many research studies, due to its favourable effects, and to the significant role it may exert on improving the obesity condition. Therefore, this study aims to investigate the effects of flavanol-rich dark chocolate consumption on metabolic profiles of obese adults using metabolomic approach.

Overnutrition and sedentary lifestyle are the leading factors associated with the development of obesity. Obese adults usually are advised to make lifestyle modifications which include dietary restriction and physical activity recommendation. In addition, dietary supplements and medication such as anti-hypertensive, lipid lowering drugs are used to achieved targeted body weight of obese adult. Therefore, the confounding factors in this study namely dietary intake, physical activity, medication, supplements were controlled throughout the study. These factors including smoking were also controlled as it will affect the metabolites. Imbalance between energy intake and expenditure results in adipose tissue expansion due to excessive lipogenesis in adipose tissues. Generally, it is well accepted that adipose tissue expansion in an obese state is accompanied by elevated inflammation. Oxidative stress and pro-inflammatory processes are strongly related. Increased abdominal adipose tissue accelerates the production of pro-inflammatory cytokines which promote increased generation of ROS, both inflammation and oxidative stress play a significant role in the development of insulin resistant thus further are associated with the degree of metabolic dysfunction. It was hypothesized that cocoa flavanol with the properties of anti-inflammation, anti-oxidative and antiobesity properties may reduce the oxidative stress and inflammation, subsequently reduce the insulin resistance and thus improved the outcome measurements in obese adult. In order to measures the altered metabolite in the urine and blood serum following cocoa rich flavanol consumption in dark chocolate in obese adult, a metabolomics based approach is used in this study. This study is a randomized, open-labelled, parallel controlled trial where the intervention group will receive 20 grams of dark chocolate, daily for 12 weeks while the control group will receive 20 grams of white chocolate daily for 12 weeks. Measurement will be taken including sociodemographic, anthropometric measurement, diet and physical activity questionnaire, blood and urine samples at baseline and 12 weeks of intervention. Obese male adult aged 18-45 years old will be recruited