Consumption of sugar-sweetened beverages (SSBs) has been linked to rising rates of overweight and obesity. The most prominent mechanism to explain the link between SSBs and obesity is that liquid calories are not perceived by the body; thereby, promoting less satiety, less energy compensation and more weight gain than does the same energy consumed in solid form. This view is supported by pooled analyses of acute preload trials that have primarily measured food intake as the outcome. Though failure of short-term compensation has been observed with liquid calories, results from these acute preload trials should not be extrapolated to infer that liquid energy sources lead to weight gain over the long-term. To date, it is unclear whether liquid calories have differential effects than solid calories on body weight gain over the longer term. To increase clarity in this issue, the investigators propose to conduct a systematic review and meta-analysis from long-term controlled feeding trials to distinguish the contribution of liquid calories from solid calories on body weight over the long-term. The findings generated by this analysis will improve the health of consumers through informing evidence-based guidelines and improving health outcomes by educating healthcare providers and patients, stimulating industry innovation, and guiding future research design.