Seven studies (n=468) were included in the review: four randomised controlled trials (RCTs; n=262), one quasi-experimental study (n=145), one experimental study (n=36) and one study without a control group (n=25)
Methodological limitations of the studies included small sample sizes, the absence of statistical data, and incomplete description of the study sample (e.g. gestational age not reported, treatment groups not comparable at baseline, and high drop-out rates).
One quasi-experimental study (n=145) compared scheduled, semi-demand and strict demand feeding regimens. It reported that strict demand feeding was associated with the consumption of larger volumes of formula, increased weight gain over a shorter time period, and a significantly shorter hospital stay in comparison with the other regimens.
One study without a control group (n=25) reported that 20 infants successfully completed a programme of demand feeding and 5 infants failed.
One RCT (n=37) reported that demand-fed infants had significantly fewer feeds per day and feedings via gavage, and were discharged 6.2 days earlier than schedule-fed infants. The mean weight change was lower in demand-fed infants: 11.2 versus 14.6 g/day.
One RCT (n=74) compared self-regulatory feeding (feeding till tired plus non-nutritive sucking) with control (urged to take complete bottle once each shift using faster flow nipple). It reported that self-regulatory feeding was associated with significant improvement in behaviour measures, and the infants were more commonly asleep at the end of feeding and less frequently in a restless state. self-regulatory feeding was associated with significantly greater weight gain among lighter infants (<150 g): 24.4 versus 8.9 g/day (p<0.0003). There was no difference between treatments in weight gain among heavier infants (>1,500 g).
One RCT (n=29) reported that demand feeding was associated with a non-significantly increased weight gain, a lower calorie consumption per 24 hours, and a non-significant decrease in hospital stay (1 day less) in comparison with scheduled feeding.
One RCT (n=78) compared ad libitum feeding with scheduled feeding and factored in comparisons of two different formula caloric density. It reported no significant effect on weight change from the feeding regimen, calorie density, or an interaction between feeding regimen and caloric density. One RCT (n=81) compared semi-demand (infants assessed for hunger every 3 hours) with a control feeding regimen (gradually increasing oral feeds). It reported that semi-demand feeding was associated with a significant decrease in the time to full oral feeding (5 versus 10 days, p<0.001) and a significant decrease in the duration of hospital stay. There was no significant difference between regimens in the rate or amount of weight gain.