Adequate nutritional intake is important to optimise performance, but can be affected by nutritional barriers within variety of amateur and trained athletes including rugby union players. However, little is known about the differences in these nutritional barriers between young college amateur (YA) and semi-professional (SP) rugby union players, and whether dietary practices in each group reflect these barriers. Seventeen players were recruited to represent two groups of SP (N = 7, age = 21.3 ± 3.1, training = 16.2 ± 2.9 h/wk, BMI = 26.6 ± 1.4) and YA (N = 10, age = 15.4 ± 0.7, training = 4.7 ± 1.8 h/wk, BMI = 21.8 ± 2.3). All participants were evaluated for their current dietary intake using a 4-day diet diary which was analysed and compared between the two groups for main macro- and micronutrients, fluid and energy intake, and were also evaluated for their nutritional barriers, attitude and knowledge using a validated questionnaire. Questionnaires were analysed using cross-tabulation and were compared for highest prevalence for each barrier (%) between the two groups. Results showed a significantly lower nutritional knowledge scores in YA than SP (18.0 ± 2.3 vs. 21.0 ± 0.0, p < 0.05), but no difference was found in the attitude towards nutrition scores between the groups (10.5 ± 1.43 vs. 12.13 ± 1.95) for YA and SP respectively. This is in spite of that higher percentage of SP stating that they were not able to meet their nutritional needs than YA (57% vs. 30% for SP and YA respectively), with the main reasons being lack of desire to cook, lack of time for SP compared with YA reasons which were money, eat whatever is cooked for them. Furthermore, the group's dietary analysis showed that YA were better matched with the normative nutritional recommended values for macro- and micro-nutrients compared with SP. This suggests that differences in the attitude towards nutrition rather than knowledge need to be addressed to improve dietary habits of young rugby union players.