 The lower average effect size obtained by including all studies in the Cochrane review, despite a lack of adequate concealment or other methodological issues, is a reduction of about 33gweek. Using a two-tailed t-test, a consumption by the intervention group of 117gweek versus a consumption of 150 gweek by the control group, a SD of 120 for a 95 CI of -53.66,-12.34 and an intention to treat sample at initial enrollment of 520 260 in each arm, the study will have a power of 87.9 to yield a statistically significant result. 