Effects of weight loss interventions for adults who are obese on mortality, cardiovascular disease, and cancer: systematic review and meta-analysis

"Many of the trials had quite intensive control group interventions, and the unblinded nature of the interventions could have led to more medical treatment in control groups, tending to reduce differences between groups."

What is meant by "quite intensive control group interventions"? Since the risk ratio is determined by the relative efficacy of each comparator intervention, it would have been helpful for the authors to provide a brief description of each comparator in Table 1. Did the authors also consider conducting a sensitivity analysis to exclude comparators that were more "intensive"?