Current nutritional guidelines encourage the reduction of fat intake from animal sources like dairy products. The aim was to determine whether the consumption of low-fat dairy is related to poorer dietary intake and nutritional status in cancer patients at risk of malnutrition. This cross-sectional included patients with solid or hematological malignancies at risk of malnutrition. Nutritional status was studied using Subjective Global Assessment, anthropometry, and grip strength. Dietary intake was evaluated with a 24-h recall and dairy consumption with a structured questionnaire. Seventy-four patients were recruited; 71.6% males of 64.8 yr, most with gastrointestinal malignancies. Only 37.8% consumed whole milk, and 61.4% consumed whole yogurt. Reasons for consumption of low-fat dairies were healthy diet (58.0%), hypercholesterolemia (20.0%), and digestive intolerance (10.0%). There were similar rates of malnutrition according the type of dairy (whole 60.9% vs. low-fat 66.7%, P = 0.640). Low-fat dairies were related to a reduction in energy (whole 1980.1 kcal vs. low-fat 1480.9, P = 0.007) and protein intake (whole 86.0 g vs. low-fat 63.0 g, P = 0.030).