Meta Platforms Inc.’s photo-sharing app Instagram is encouraging users to take a break as the company battles accusations that too much time spent on its social networks hurts the mental well-being of teenagers. Instagram will let people opt to see pop-up messages when they have spent a lot of time looking at a particular topic, suggesting they explore other subjects. Users also can decide to be nudged to take a break after they have spent 10, 20 or 30 consecutive minutes on the app, Instagram said Tuesday in a blog post. Meta shares are up 16% for the year and are trying to find support above $300.