Comparison of short-term energy intake and appetite responses to active and seated video gaming, in 8-11-year-old boys.

The acute effects of active and seated video gaming on energy intake (EI), blood glucose, plasma glucagon-like peptide-1 (GLP-17-36) and subjective appetite (hunger, prospective food consumption and fullness) were examined in 8-11-year-old boys. In a randomised, crossover manner, twenty-two boys completed one 90-min active and one 90-min seated video gaming trial during which food and drinks were provided ad libitum. EI, plasma GLP-17-36, blood glucose and subjective appetite were measured during and following both trials. Time-averaged AUC blood glucose was increased (P=0·037); however, EI was lower during active video gaming (1·63 (sem 0·26) MJ) compared with seated video gaming (2·65 (sem 0·32) MJ) (P=0·000). In a post-gaming test meal 1 h later, there were no significant differences in EI between the active and seated gaming trials. Although estimated energy expenditure was significantly higher during active video gaming, there was still no compensation for the lower EI. At cessation of the trials, relative EI (REI) was significantly lower following active video gaming (2·06 (sem 0·30) MJ) v. seated video gaming (3·34 (sem 0·35) MJ) (P=0·000). No significant differences were detected in time-averaged AUC GLP-17-36 or subjective appetite. At cessation of the active video gaming trial, EI and REI were significantly less than for seated video gaming. In spite of this, the REI established for active video gaming was a considerable amount when considering the total daily estimated average requirement for 8-11-year-old boys in the UK (7·70 MJ).

Calcium ingestion suppresses appetite and produces acute overcompensation of energy intake independent of protein in healthy adults.

BACKGROUND: Prior evidence suggests that high-calcium intake influences postprandial appetite and insulinemia, possibly due to elevated incretins. In vitro and ex vivo models demonstrate that extracellular calcium and protein synergistically enhance secretion of incretins. This is yet to be shown in humans. OBJECTIVE: This study was designed to assess energy intake compensation in response to protein and calcium ingestion. METHODS: Twenty healthy adults (13 men; 7 women) completed 4 trials in a randomized, double-blind crossover design separated by ≥48 h. During the trials, each participant consumed a low-calcium and low-protein control preload [(CON); 4 g and 104 mg, respectively], a high-protein preload (PRO; 29 g), a high-calcium preload (CAL; 1170 mg), or a high-protein and high-calcium preload (PROCAL). Blood samples were collected at baseline and 15, 30, 45, and 60 min after preload ingestion to determine insulin and incretin hormone concentrations. Energy intake was assessed by a homogenous test meal 60 min after the preload. Visual analog scales were completed immediately before blood sampling to assess subjective appetite sensations. RESULTS: Relative to the CON, the PRO produced 100% (95% CI: 85%, 115%) energy compensation, whereas the CAL produced significant overcompensation [118% (95% CI: 104%, 133%)], which was significantly more positive than with the PRO (P < 0.05). The PROCAL resulted in energy compensation of 109% (95% CI: 95%, 123%), which tended to be greater than with the PRO (P = 0.06). The mean difference in appetite sensations relative to the CON was not significantly different between the PRO (-3 mm; 95% CI: -8, 3 mm), CAL (-5 mm; 95% CI: -9, 0 mm), and PROCAL (-5 mm; 95% CI: -10, -1 mm) (P > 0.05). CONCLUSIONS: The addition of protein to a preload results in almost perfect energy compensation, whereas the addition of calcium, with or without protein, suppresses appetite and produces overcompensation of subsequent energy intake. The role of circulating insulin and incretin concentrations in these responses, however, remains unclear. This trial was registered at clinicaltrials.gov as NCT01986036.