Obesity and overweight are linked to diseases that cost society a significant amount of resources. While behavior modification can reduce the problem, instigating such lifestyle changes is an uneasy task. One potential way to reduce the problem is through the use of financial incentives. In this survey, we review the available evidence, properly emphasizing studies that credibly yield meaningful estimates of the effect of financial incentives on weight loss. We find that the scientific literature on the subject has not yet satisfactorily settled whether such a mechanism is effective at eliciting the desired behavioral and health outcomes. We therefore advocate a rigorous large-scale randomized experiment to provide reliable estimates of the effect.