The present study revealed that, most of participants had poor nutrition knowledge. Although majority 88 % of the participants had basic nutrition training in medical/nursing school, there appeared to be a number of gaps in their nutrition-related knowledge. The knowledge level of healthcare workers was found to be higher (Table 1) due to the nutrition education received and higher level of professionalism in the application of their knowledge. The increase in knowledge scores was not found to be in related with the increase in professional experience, instead healthcare workers who had fewer years of practices scored high. This could be due to current nutrition updates and their personal initiatives through reading from different sources as they mentioned their sources of nutrition knowledge.
Similar observation was explained by another evaluation study in USA where it was reported that clinical experience didn’t increase the level of the nutritional knowledge among licenced nurses working in nursing homes, it was also showed that there was a correlation between the educational substructure and the nutrition knowledge score. Yalcin et al.,  in their study on nutrition knowledge level of nurses in Zonguldaki in Turkey indicated that long-term clinical experience without any special education on nutrition and with no working experience in this field does not increase the nutrition knowledge.
In this study, healthcare workers scored high in questions that were medical related but they scored low in nutrition related questions (Table 2). This could be due to less emphasis on nutrition training in medical/nursing schools as mentioned during group discussion that nutrition knowledge they gained was not adequate to provide nutritional counselling and support to CKD patients (Table 5). These findings are consistent with other studies that showed the inadequacy of education regarding nutrition in medical and nursing programs and the requirement of expanded content of nutrition in the curricula [12, 13].
According to Kim , in the study on Nurses’ positive attitudes to nutritional management but limited knowledge of nutritional assessment in Korea identified that limited education in nutrition could lead nurses to be negligent in managing patients’ nutritional problems. This observation is important as it has been shown that nurses are a trusted source of health information as noted in the study by Harrison .
The lack of knowledge about nutrients (minerals, protein, and carbohydrate) adjustment is of particular concern, as there is growing interest on changes in disease patterns in relation to foods and nutrition . Doctors and nurses are perceived to be the most reliable source of nutritional information. Therefore, it is important that information provided by health professionals is accurate. As found in this study that only few healthcare workers have the time, knowledge or skills to give nutritional advice or to recognize nutrition related problems, similar observation were found by other studies [14, 17].
Participants felt that nutrition plays an important role in prevention and treatment of disease. However, 72.4 % of nurses reported that they were not knowledgeable in nutrition related matters and that nutrition assessment was the responsibility of nutritionists and doctors. In places where nutritionist services are not available as is common in most hospitals in Tanzania, nurses tend to fully depend on doctors for guidance as far as nutritional management of patients is concerned.
Furthermore, results indicated that 76.7 % had negative attitude regarding their own nutritional knowledge. This was revealed when they were asked to rate themselves on nutrition related matters. This could be due to inadequate nutrition training in medical/nursing schools and as part of in-service trainings in patient care. Such negative attitudes were expressed during group discussion when they were asked to give opinion on nutrition knowledge in their professional training. Different studies have revealed that in-service nutrition training can help to improve health workers’ nutrition knowledge [18, 19]. This may facilitate positive changes in their attitudes toward nutrition care and thus in their behaviour [19, 20]. As a result, health workers’ skills in management of nutrition-related problems including nutrition-counselling skills [20–22].
According to Fischbein’s learning theory, behaviour or attitude change is mediated through cognitive processes and thus is learned through imitating and observing the actions of others . Accordingly, the reward that health workers can gain from their nutrition actions, such as better nutritional status or feeding practices in those they treat, may reinforce their counselling actions, thus making it a permanent habit. In this way, the quality of health workers with regard to nutrition counselling might be expected to improve.
In this study an assessment of a patient’s nutritional condition was not always performed. Instead, the patient’s condition, diagnosis, treatment and age were taken into consideration as criteria for diagnosis. The reasons might be found in inadequate knowledge and skills, or perceived lack of resources, such as assessment tools and guidelines (Table 5). These factors may also explain the finding of low frequencies of nutrition education sessions services, such as nutritional support (Table 4). Limited use of assessment tools confirmed by another study . Another reason could be that the doctors use their clinical judgement and therefore abandon the nutrition assessment tools . In addition, nurses assume that nutritional assessment is not part of their role, the fact which has been discussed recently .
This study was conducted using intentional sampling of healthcare workers from a single municipality, and given the cultural particularities of this group, extrapolations of the finding s are limited. Furthermore, the study did not cover all medical conditions related to nutrition, and this is another limitation of this study.