According to their wishes and goals, each athlete chooses the type and intensity of the training to achieve maximum physical readiness. With the plan of training athletes must also have a program of diet because the food should meet the nutritional needs of athletes during training, competition and recovery. Respectively, the food should provide enough energy and meet the needs of essential nutrients. The paper presents the results of research, behavior and attitudes of athletes in the context of proper nutrition. The survey was conducted at the beginning of June 2017 in Karlovac, and used conveniently prepared questionnaire. A random sample included 100 respondents who are engaged in baseball, football, volleyball and handball. Descriptive statistics analysis was carried out in Microsoft Office Excel 2007. Nearly 71% of respondents do not think about their diet, but take care of proper hydration of the organism (71%) and men (46%) are considerably more attentive to women (25%). Only 41% of respondents identify carbohydrates as the primary source of energy but slightly more respondents are familiar with the daily intake requirements (62%). A similar attitude respondents have to fats and proteins. Most respondents understand the importance that proper nutrition has for athletes' health, but inadequate knowledge causes inadequate eating habits. Every athlete needs to take care of diet and in the future need to invest a lot of effort to change the habits of athletes in order to achieve a positive impact on health and better sports performance.