Obesity is a multi factorial disease dependent on

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Obesity is a multi-factorial disease, dependent on genetics (if your parents are obese, your chances of becoming obese are increased), hormones (such as thyroid hormones, growth hormones, and stressrelated hormones, such as epinephrine), and the environment.The influences and some potential causes of obesity are clearly explained in section 9.2 and should be read and understood.Leptin , Ghrelin, and Uncoupling proteins are important components in the understanding of obesity and genetics presently being studied. Some key points are described below. Leptinoobis an “obesity gene” expressed in fat cells and codes for the protein LeptinoLeptin actions as a hormone are primarily in the hypothalamusoLeptin is secreted from adipose tissue (fat cells) and stomach cellsoLeptin promotes a negative energy balance by suppressing appetite and increasing energy expenditureoGenetic deficiency of leptin is extremely rare but has been found in some extremely obese children. Without leptin there is little appetite control therefore one is constantly hungry. These children lost substantial amounts of weight with leptin injections. Leptin injections are only effective for weight loss ifthere is a leptin deficiency.oLeptin levels tend to increase with body fat levels, perhaps to overcome an insensitivity or resistance to leptinGhrelinoA hormone which is secreted mainly by stomach cells and acts mainly in the hypothalamusoIt increases appetite and decreases energy usage
Think about what would happen to ghrelin levels if someone is on a low kcalorie diet.Uncoupling ProteinsTwo Types of Fato1.White fat (White adipose tissue): stores fat for other cells to use for energy2.Brown fat (Brown adipose tissue): releases stored energy as heatGenerally when fat is oxidized, some energy is released in heat and some is captured in ATP.In brown fat heat is produced instead of ATP, which is important in newborns, freezing climates, and in hibernating animals. Most adult humans have only small amounts of brown fat (generally less than 1%). Brown fat quantity seems to be inversely related to BMIEnvironmentEnvironmental cues serve as the most influential, and most controllable of these factors. We live in a society riddled with convenience stores and fast food restaurants, providing high fat, low cost, arguably delicious food products, which provide many kcalories per gram; they are energy dense. Furthermore, many people couple this eating pattern with excessive television and screen time, which encourages little activity and at the same time entices people by showing commercials marketing delicious-looking foods and drinks. As reported in the American Journal of Clinical Nutrition. 82(1 Suppl):236S-241S, 2005 Jul. largerportion sizes likely play a role is the obesity epidemic. There has been an increase in obesity which parallels the increase in portion sizes of foods both at home and away from home.

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