Background & aims The severity of pain is routinely assessed in hospitalised patients but the impact of pain and pain control on energy coverage has been poorly studied. This One-day cross-sectional observational study assessed the association between severity of pain and coverage of energy needs in hospitalised patients. Methods Foods provided and consumed were assessed on one day by dedicated dieticians for unselected hospitalised patients receiving three meals per day. Severity of pain was evaluated by a visual analogue scale at the mealtimes, averaged over the study day, and categorized as no pain, slight, moderate or severe pain. The coverage of energy needs was expressed in percentage of predicted needs. Results Among the 755 included patients, 63% reported having pain. Severe pain was associated with a lower energy coverage than no pain (p = 0.001) or slight pain (p = 0.001). Insufficient energy coverage, defined as ≤70% of predicted needs, occurred in 13% of the patients. In univariate logistic regressions, predictors of insufficient energy coverage were severe pain as compared to no pain (OR 2.38; 95% CI 1.21, 4.64) and treatment with opioid drugs as compared to no pain killer (OR 1.73; 95% CI 1.07, 2.79). When including sex, age, body mass index, treatment with analgesics and severity of pain in a multivariate logistic regression, severe pain more than doubled the risk of insufficient energy coverage (OR 2.32; CI 1.15, 4.66). Conclusions Patients experiencing severe pain have a high risk of insufficient energy coverage. Optimal pain control is probably critical to prevent underfeeding in the hospital.