Darden is an 18-year-old male who is in his first year of undergraduate education at the state university. He hasn’t yet declared a major but is leaning toward a dual degree in business and environmental studies. Darden lives in a residence hall on campus, where he has a 12-meal-per-week meal plan. He usually skips breakfast because he doesn’t get up early enough to get to the cafeteria before his 9 a.m. class. He does stop at a coffee shop on his way to class several times per week, where he usually orders a macchiato or mocha coffee drink.

Darden eats lunch and dinner at the cafeteria most days of the week. He tends to focus on foods that are quick to eat, such as chicken sandwiches, pizza, french fries, chicken fingers, and burgers. Occasionally, he will focus on the salad bar or sandwich bar, but often doesn’t feel he has the time to do this. On weekends, he usually eats brunch late in the morning, snacking the rest of the day. Darden does have a mini-fridge and microwave in his dorm room, which he shares with a roommate. He keeps nonperishable foods in his room such as chips, cookies, ramen noodles, and microwave popcorn; the mini-fridge is mostly used to store soft drinks and sports drinks. There are no grocery stores on campus so he buys his food and beverages at either the big-box pharmacy chain store or the convenience store close to his residence hall.

Darden has an interest in sustainable food practices, so he joined an environmental justice group on campus. The group frequently discusses topics related to animal welfare and the impact of feedlots on climate change. Darden has decided to follow the lead of his fellow group members and become a vegetarian, eliminating red meat, poultry, and fish from his diet. Within two months of becoming a vegetarian, he decided to give up all animal protein, including eggs and milk. He also avoids foods with high fructose corn syrup and preservatives when possible. Rather than gain the “freshman 15” he seems to have lost a bit of weight as his clothes fit looser than at the beginning of the semester.

What are nutrients of concern for Darden, given his current diet and his biological age?