On the evidence. Largely a matter of size.
O'Meara
S
S
Glenny
A M
AM
Turner-Boutle
M
M
D002986:Clinical Trials as Topic; D019317:Evidence-Based Medicine; D006292:Health Priorities; D006302:Health Services Research; D006801:Humans; D009765:Obesity / Q000453:epidemiology* / Q000628:therapy; D013222:State Medicine; D006113:United Kingdom / Q000453:epidemiology; D015431:Weight Loss