| Popis: |
For many normal weight individuals, energy balance is a regulated process; over time, energy intake from food is in equilibrium with energy expenditure from both obligatory and adaptive heat production. The result is a relatively stable body fat content. In obese individuals, disturbances occur in energy balance. The catecholamine neurotransmitter — norepinephrine — is involved in several functions in the brain, including stimulation of hunger and satiety and thermogenesis. In peripheral organs served by noradrenergic neurons such as brown and white adipose tissue, norepinephrine is predominantly catabolic, resulting in an increase in metabolic rate. Recent evidence that norepinephrine metabolism is altered in obese humans and reduced in genetically obese (ob/ob) mice may be important in explaining some of the alterations in energy balance regulation that occur in the development of human obesity. Dietary manipulations that enhance central and peripheral noradrenergic activity — such as a high carbohydrate, low protein diet — may be metabolically advantageous to obese dieters. |
