Objective A systematic review was conducted to address this clinical question: Does consumption of (non-dairy) sugar-containing beverages (SCBs) among children under age 12 result in excess weight gain? Methods The authors searched four databases for controlled trials (randomized and non-randomized) and cohort studies published in English through March 29, 2016: PubMed, EMBASE, Cochrane Database of Systematic Reviews, CINAHL. Initial and full-text screening, data abstraction, and risk of bias assessment were performed independently and in duplicate. Results Thirty-eight studies met inclusion criteria for this systematic review. One was a randomized controlled trial, and 37 were cohort studies. Though the results of these studies were mixed, the majority demonstrated a statistically significant positive association between SCB consumption in children under age 12 and total adiposity and central adiposity. In contrast, most studies that assessed 100 percent fruit juice consumption only with either total adiposity or central adiposity did not support an association. Among only children under age 5 at baseline, no studies examined central adiposity, but nearly all studies examining SCBs and total adiposity, and a majority examining only fruit juice consumption, demonstrated a statistically significant positive association. Conclusion Our results support a statistically significant positive association between SCBs and total and central adiposity among children under age 12. This association is most consistent for total adiposity among children <5. Our results for 100 percent fruit juice only suggest differences by age, as most studies among those < 12 were negative but most among those <5 were positive.