By Thomas Gaskin and Soheil Isonlani

 Carbohydrates, fat and protein all contain and store energy NutrientEnergy Content per 100g Carbohydrate1760kj Fat4000kj Protein1720kj

 Hypothalamus is the appetite control centre- located in the brain  It knows when you have eaten enough food through hormonal stimuli:  Insulin- secreted in pancreas when glucose levels are too high  PYY secreted by the small intestine, where the food is kept  Leptin- secreted by adipose tissue, as more fat stores, the more leptin is released

 Diets are important around the world, and certain foods are the main source of energy and are eaten in large quantities:  Rice- tropical and temperate areas  Wheat- temperate climates  Cassava- high rainfall areas  Fish- where crop growth is impossible  Meat- ethnic groups with a nomadic lifestyle

Body Mass IndexConclusion Below 18.5Underweight Normal weight Overweight 30.0 or moreObese

 Consumption of too much sugar can result in obesity, type 2 diabetes and tooth decay  Too much starch can cause obesity but it is not linked to other health problems  Dietary fibre is the most complex indigestible and can be very healthy

 Significant risk of obesity with large consumption  There is a link between fat and coronary heart disease (CHD)  Trans fats are known to have the largest risk and saturated fats are also very unhealthy

 Proteins are usually a large part of certain diets, which means one can consume a lot of it in one meal  Can cause kidney stones, gout, reduced kidney function, loss of calcium in urine and risk of osteoporosis

 Over 300 million adults worldwide are considered clinically obese  Clinical obesity is when a doctor diagnoses a patient as obese

 Foods with high content of fat and sugar are cheap  Economic growth- cheaper foods allowed larger portion of sizes  Automated means of transportation  People do not have physically demanding jobs  Many jobs are done by machine  Overall the main reason is that we are eating more and consuming a lot of energy stored as fat, but we are doing less activities that expend this energy