Impact of a 3-Month Anti-inflammatory Dietary Intervention Focusing on Watermelon on Body Habitus, Inflammation, and Metabolic Markers: A Pilot Study

An anti-inflammatory dietary intervention called the Inflammation Management Intervention (IMAGINE) was adapted to emphasize watermelon due to its anti-inflammatory properties. This pilot study (n = 23) tested the effect of a watermelon-enhanced IMAGINE intervention (n = 15) on body habitus and markers of inflammation and metabolism. This 3-month self-selection trial, consisting of weekly in-person classes and online education for 12 weeks, focused on incorporating watermelon into an already anti-inflammatory diet. Controls (n = 8) received basic health education via email and blogs. Measurements, including diet, anthropometrics, actigraphy, and a blood draw, were made at baseline and immediately postintervention. Linear regression analyses were conducted using intervention status as the main exposure. Post hoc analyses then ignored intervention assignment and grouped participants based on their change in their energy-adjusted Dietary Inflammatory Index (E-DII^TM) score. There were no group-by-time interactions for any of the studied outcomes. However, some intervention participants' diets became more proinflammatory, and several control participants' diets became more anti-inflammatory. Those participants below the median of E-DII change (ie, more anti-inflammatory changes) showed reductions in body fat percent (-1.27% vs +0.90%, respectively, P = .01), body mass index (-0.66 vs +0.38 kg/m², respectively, P = .06) and body weight (-0.99 vs +0.54 kg, respectively, P = .08) compared to those above the median of E-DII change. This study demonstrates that individuals who adopt a more anti-inflammatory diet containing watermelon will have improvements in body anthropometrics. Future studies should focus on increasing adherence and compliance to intervention prescriptions, exploring options to extend interventions to evaluate long-term changes, and further examining changes in inflammatory biomarkers. Clinical Trials Registration: NCT03158740.