The one thing we are incredibly proud of at Fitness Plus is that members pick our brains and ask us all sorts of questions. 9 times out of 10 when people get stuck with their diet they don't ask questions.

Speak to trainers at your gym, ask someone who is proven to know the answer. Your friends that you attend the gym with occasionally probably won't know the answer and won't give you a correct answer. 
If your a female who has been following her diet to the letter, but one week put weight on. But you can't understand why, would you know that it's possibly due to the hormone regulation from time of the month and it causing more water to retain.

- If you're stuck with something, even if it's exercise or nutrition don't hesitate to ask. We get inundated with questions week in and week out off people who are stuck one way or another. It's best to ask early on, that way you can address the issue and get it resolved as soon as possible to get you back on track with your goal.