Answer:
social inhibition
Step-by-step explanation:
Based on the scenario being described within the question it can be said that Samantha's eating behavior demonstrates social inhibition. This term refers to the inability to perform a certain task when in the presence of others. Which is what Samantha is struggling with in this situation since she can only maintain her diet accordingly when she is eating alone, but seems to be unable to do so in the presence of her friends.