Comparison of the energy retention of carbohydrates and fat

W. Jentsch, M. Derno, Dummerstorf

The utilization of available energy of carbohydrates and fat for fat deposition was compared. The studies were performed in rats, pigs and humans with limited physical activity in respiration chambers by means of the nitrogen and carbon balance method.

The following values for energy retention and efficiency of utilization of available energy were obtained:

Nutrient

Energy retention

Efficiency of utilization (%)

Pig

Rat

Man

Pig

Rat

Man

Fat

33.8

33.6

-

85.9

83.1

-

Starch

12.5

12.9

12.9

75.7

75.5

75.8

Saccharose

12.1

12.2

-

74.6

73.3

-

Cellulose

7.0

-

-

70.6

-

-

The relation of the energy retention values of starch and sugar : fat : cellulose were 23 : 64 : 13. The utilization of available energy of starch for fat deposition has been found to be similar in humans, pigs and rats. A daily intake of 6876 kJ of starch energy by man with limited physical activity to a basal diet resulted in a total energy deposition of 5133 kJ, corresponding to a fat energy of 4912 kJ/d and to a daily lipogenesis from starch of 124 g.

Although the energy retention of fat is 2.5 times that of starch and sugar, high intakes of these may result in remarkable fat deposition under conditions of reduced physical activity. In the light of obesity prevention, carbohydrates hence should not be eaten ad libitum. This may apply to cellulose , but not to starch and sugar as demonstrated, although energy equilibrium with fat intake is exceeded faster. EU09/02

Keywords: Energy retention / carbohydrates / fat

Sie finden den Artikel in deutscher Sprache in Ernährungs-Umschau 09/02 ab Seite 336.