There was a relatively small amount of data available for breast cancer recurrence (281 participants from 4 intervention‐comparisons with 14 recurrence events RR 1.95, 95% CI 0.68 to 5.60 low‐quality evidence) and the analysis was likely underpowered.
There were no time‐to‐event data available for overall survival, breast cancer recurrence and disease‐free survival. The duration of follow‐up ranged from three months to 36 months. The duration of interventions ranged from 0.5 months to 24 months. Participants in the controls groups either received usual care, written materials or placebo, or wait‐list controls. Participants in the experimental groups received weight loss interventions using the core element of dietary changes, either in isolation or in combination with other core elements such as 'diet and exercise', 'diet and psychosocial support' or 'diet, exercise and psychosocial support'.
We included a total of 20 studies (containing 23 intervention‐comparisons) and analysed 2028 randomised women.
