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.