Problem-based learning using authentic material from the web was used to teach metabolism in a biochemistry course. In place of traditional lectures, students' analyzed health or nutrition articles from newspapers and magazines, which were debatable from a scientific point of view, following the principles of problem-based learning. A mixed method was used to assess the students' perception, use of sources of information and web services while performing the task, and changes in self-directed learning. Students' perception was particularly positive. The majority stated that the methodology helped them to apply knowledge to real life and that they learned about the topic analyzed by their group. The perception that problem-based learning promotes the ability to solve problems, critical thinking, and collaborative work is noteworthy. Tutors considered that teams identified the problem and concluded correctly, noticing students' enthusiasm and motivation. The methodology also promoted scientific reading. More importantly, a significant improvement in self-directed learning of the 2014 cohort was detected. This intervention suggests that this methodology is a valuable alternative to motive and promote self-learning; representing an opportunity to shift the focus of instruction from the teacher to the student. The design of the activity and materials are described in detail. Also, limitations and solutions are discussed.