Friday, November 26, 2010

obesity and underweight.. part 1

i was studying nutrition right now, on topic, obesity and underweight.obesity and underweight is related to the energy balanced in the body. where:
energy input= energy output
energy input can be define as energy intake in our body such as food that contains carbohydrates (CHO), fats and protein. these nutrients are energy yielding nutrients. where the energy output can be defined as the energy that will use in the body during basal metabolism, thermic effects of food, physical activity and non exercise activity thermogenesis.

energy are stored in the body in three type which is
+fat or adipose tissue (fats)
+glucose or as glycogen in the liver(carbohydrates) if excessive it stored as fats
for protein, the excess protein in the body will be used as energy source but if there is more protein left, it will be stored as fat.

usually body refer to the CHO as energy sources. brain and heart craving for glucose as their sources of energy. Physical activity encourage the burning of the dietary fats through beta oxidation. for endurance athlete, the fatty acids and glycogen which will convert into glucose will be used as energy.

Physical activity can be activated through basal metabolism rate (BMR). more active, more energy burned. remember, lack of activity are the major cause of the obesity.

instead of the physical activity, the satiety regulator with that means the feeling of fullness. is really important. the metabolism of the satiety starts when the hypothalamus (in the brain) send signal to eat when feeding cells stimulated. and when the satitey cells are stimulated , hypothalamus send signal to stop eating. that in the normal situation.

the symphatetic nervous sytem plays role to send the signal to stop eating when the activity increase aand send the signal to start eating when the activity are decrease. which these means, when the stomach are full with food, the activity to digest the food with increase and when the food is slowly digest the activity of the stomach decrease. the stomach is empty again and we need to eat again..


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