In-hospital malnutrition and inadequate food intake have been associated with negative outcomes (e.g., prolonged length of stay, readmission, mortality, and increased hospital costs). Studies examining the factors associated with low food intake in hospital, commonly defined as the consumption of ≤50% of meals, have produced mixed results. We examined the correlates of food intake including patient socioeconomic, demographic, and health characteristics, institutional factors, and common clinical strategies in 1129 medical patients from 5 Canadian hospitals. Low food intake was found in 35% of patients (41% of females and 29% of males) (p < 0.001). In multivariate analyses, sex, socioeconomic status, demographics, and diagnoses were not significantly related to food intake. Patients assessed as malnourished (subjective global assessment (SGA) B/C) (odds ratio (OR), 2.41; p = 0.003) or as not at risk of malnutrition (OR, 1.67; p = 0.040) were more likely to have low intake when compared with those assessed as well nourished (SGA A). Patient reports of mealtime challenges (OR, 2.70; p < 0.001) and barriers to food intake (OR, 1.11; p = 0.008) were positively related to low intake throughout the study sample. Higher 12-Item Short Form Health Survey Mental Component Summary scores were related to better food intake (OR, 0.98; p < 0.001). Clinical strategies such as between-meal snacks lowered the likelihood of low food intake (OR, 0.55; p = 0.037), whereas a group of “other strategies” increased the odds (OR, 2.77; p = 0.001). These results offer a better understanding of the correlates of in-hospital low food intake. The conclusion discusses some avenues for improving food intake in the clinical setting, such as better mealtime monitoring and a reduction in barriers to food intake.