To report the changes in nutritional status, nutrition-related complaints and risk of sarcopenia in individuals attending a primary care dietitian in the Netherlands after a COVID-19 infection. The study was registered on the clinicaltrials.gov registry (NCT04735744). Nutritional status and nutrition-related complaints were assessed with the Patient-Generated Subjective Global Assessment Short Form and body composition measurements when possible. Risk of sarcopenia was assessed with the Strength, Assistance with walking, Rise from a chair, Climb stairs and Falls questionnaire. Dietitians reported on treatment goals, content and volume of dietetic treatment. Descriptive statistics were used to describe the study population and outcomes at baseline and end of treatment. For continuous variables, paired samples t-tests were used to compare scores at the start and the end of dietetic treatment. For dichotomous variables. McNemar tests and Wilcoxon signed-rank tests were used to determine differences between the start and end of treatment. A total of 222 participants were included [mean age 50 (SD 13), 58% female, 34% overweight, 40% obese]. Malnutrition risk decreased from 44% (medium risk) and 20% (high risk) to 29% and 12% by the end of treatment (p < 0.001). The risk of sarcopenia decreased from 31% to 22% (p < 0.001). There was an imbalance between fat-free mass and fat mass in about half of the participants. The most commonly reported nutrition-related complaints were fatigue, no appetite, the feeling of being full and changed or loss of taste. Median treatment duration was 21 weeks [interquartile range (IQR) 13-26] and 5 consultations (IQR 4-7). Most participants (46%) aimed to maintain weight, with others aiming to lose (14%) or gain (14%) weight. At the end of treatment, 57% had achieved the goals. Significant improvements in nutritional status and risk of sarcopenia were observed after dietetic treatment in primary care, and most participants achieved the treatment goals. Nevertheless, nutrition-related complaints and the risk of malnutrition or sarcopenia remained prevalent.