Acute energy intake restriction, moderate intensity exercise and postprandial plasma triacylglycerol concentration in girls

Abstract

This study compared the effect of an isoenergetic energy deficit, induced by mild energy-intake restriction or acute exercise, on postprandial triacylglycerol concentrations ([TAG]) in girls. Eleven healthy girls (mean(SD): age 12.1(0.6) years; body mass 42.1(5.8) kg; peak oxygen uptake ( V ̇ O 2 peak ) 47(6) mL kg −1 min −1 ) completed three, two-day conditions in a counterbalanced, crossover design. On day 1, participants rested (CON), restricted food energy intake by 1.47(0.18) MJ (ER) or walked at 60% V ̇ O 2 peak (EX; net energy expenditure 1.46(0.01) MJ). On day 2, capillary blood samples were taken in the fasted state and at pre-determined intervals throughout the 6.5 h postprandial period. A standardised breakfast was consumed immediately after the fasting sample and a standardised lunch at 4 h. Compared with CON, fasting [TAG] was lower after ER (95% confidence interval (95% CI) −0.22 to −0.01, effect size (ES) = 0.42) and EX (95% CI −0.38 to −0.19, ES = 1.33); EX was lower than ER (95% CI −0.30 to −0.03, ES = 0.66). Differences in postprandial [TAG] over time between conditions were moderate (ES = 0.50). The total area under the [TAG] versus time curve was lower after EX than CON (95% CI −2.89 to −0.86, ES = 0.80), with a small difference between ER and CON (95% CI −1.85 to 0.16, ES = 0.27) and EX and ER (95% CI −2.48 to 0.42, ES = 0.40). An exercise-induced energy deficit elicits a greater reduction in fasting and postprandial [TAG] in girls than an isoenergetic diet-induced energy deficit.