assistant: Sure, here is a suggested workout plan for a week and a meal plan to help you gain muscle mass.

Workout Plan: Monday:

    Chest Press: 3 sets of 8-10 repetitions
    Incline Bench Press: 3 sets of 8-10 repetitions
    Lat Pulldown: 3 sets of 8-10 repetitions
    Barbell Biceps Curl: 3 sets of 8-10 repetitions
    Push-Ups: 3 sets of 8-10 repetitions

Tuesday:

    Squats: 3 sets of 8-10 repetitions
    Leg Press: 3 sets of 8-10 repetitions
    Leg Curls: 3 sets of 8-10 repetitions
    Calf Raises: 3 sets of 8-10 repetitions

Wednesday:

    Shoulder Press: 3 sets of 8-10 repetitions
    Upright Row: 3 sets of 8-10 repetitions
    Triceps Pushdowns: 3 sets of 8-10 repetitions
    Chin-Ups: 3 sets of 8-10 repetitions

Thursday:

    Lunges: 3 sets of 8-10 repetitions
    Step-Ups: 3 sets of 8-10 repetitions
    Leg Extensions: 3 sets of 8-10 repetitions
    Seated Calf Raises: 3 sets of 8-10 repetitions

Friday:

    Deadlifts: 3 sets of 8-10 repetitions
    Bent-Over Rows: 3 sets of 8-10 repetitions
    Pull-Ups: 3 sets of 8-10 repetitions
    Barbell Shrugs: 3 sets of 8-10 repetitions

Meal Plan: Monday:

    Breakfast: 2 eggs, 2 pieces of whole-grain toast, 1 banana
    Lunch: 1 cup of cooked brown rice, 1 cup of steamed vegetables, 4 ounces of grilled chicken
    Dinner: 2 cups of cooked quinoa, 1 cup of steamed vegetables, 4 ounces of grilled salmon

Tuesday:

    Breakfast: 1 cup of oatmeal, 1 cup of fruit, 1 scoop of protein powder
    Lunch: 1 cup of cooked couscous, 1 cup of steamed vegetables, 4 ounces of grilled turkey
    Dinner: 2 cups of cooked bulgur

assistant: Sure thing! Here's a one week workout plan and a meal plan for a 26 year old who is looking to gain weight and muscle. 

WORKOUT PLAN (around 3 hrs/day - 3 times/week):
    Monday (Push-day):
    Light jog (10 - 30 min)
    Bench-press (Heavy weight, 4 to 6 repetitions, 4 sets)
    Overhead-shoulder-press (Heavy weight, 3 to 5 repetitions, 4 sets)
    Skull-crusher/ overhead-tricep-extensions (Medium weight, 6 to 7 repetitions, 4 sets)
    Dumbbell-lateral-raise (Medium weight, 6 to 7 repetitions, 4 sets)
    Standing-cable-crossover (Medium weight, 8 to 10 repetitions, 3 sets)
    Low-cable-chest-fly (Medium weight, 8 to 10 repetitions, 3 sets)

   Tuesday (Rest)
   
    Wednesday (Pull-day):
    Light jog (10 - 30 min)
    Dead-lift (Heavy weight, 4 to 6 repetitions, 4 sets)
    Shoulder-shrugs (low weight, 8 to 10 repetitions, 4 sets)
    Bent-over-rows (Heavy weight, 3 to 5 repetitions, 4 sets)
    Spider-curls (Medium weight, 6 to 7 repetitions, 4 sets)
    Standing-bicep-curls (Medium weight, 8 to 10 repetitions, 3 sets)
    Lateral-pull-down (Medium weight, 8 to 10 repetitions, 3 sets)

    Thursday (Rest)

    Friday (Leg-day and Abdominals):
    Squats (Warm-up, 4 to 6 repetitions, 3 sets)
    Squats (Heavy weight, 4 to 6 repetitions, 4 sets)
    Straight-leg-calf-raises (Medium weight, 8 to 7 repetitions, 4 sets)
    Romanian-deadlift (Heavy weight, 4 to 6 repetitions, 4 sets)
    Dumbbell-stepping-lunge (Medium weight, 6 to 7 repetitions, 4 sets)
    Side-lounge (Medium weight, 6 to 7 repetitions, 4 sets)
    Weighted-Russian-twist (Low-eight, 8 to 10 repetitions, 4 sets)
    Weighted-leg-curl-ups (Medium-weight, 8 to 7 repetitions, 4 sets)
    
   Saturday and Sunday (Rest)
    
    Safety comments: The gym can be a source of injuries specially if you are inexperienced. So always make sure you don't go past your limit, stay hydrated, and listen to your own body. In addition, try to always clean your equipment after every use, and practice respectful gym etiquette.

MEAL PLAN:

    Monday:
    Breakfast: 3 scrambled eggs with cheese, whole grain toast, and a glass of orange juice
    Snack: Greek yogurt with mixed berries and almonds
    Lunch: Grilled chicken breast, brown rice, and steamed vegetables
    Snack: Peanut butter and banana sandwich on whole grain bread
    Dinner: Grilled salmon with quinoa and roasted sweet potatoes
    Snack: Rice cakes with nut butter and honey
    
    Tuesday:
     Breakfast: Oatmeal with almond milk, banana, and cinnamon
     Snack: Apple slices with peanut butter
     Lunch: Turkey and cheese sandwich on whole grain bread, carrot sticks, and a side of hummus
     Snack: Nuts and dried fruit mix
     Dinner: Beef stir-fry with vegetables and brown rice
     Snack: Whole grain crackers with cheese and deli meat

    Wednesday:
    Breakfast: Smoothie bowl with banana, strawberries, almond milk, and protein powder
    Snack: Rice cakes with avocado and salsa
    Lunch: Grilled chicken salad with mixed greens, cherry tomatoes, and avocado
    Snack: Cottage cheese with mixed berries
    Dinner: Baked chicken breast with roasted potatoes and green beans
    Snack: Whole grain crackers with nut butter and honey
    
    Thursday:
    Breakfast: Whole grain pancakes with peanut butter and syrup
    Snack: Rice cakes with almond butter and jam
    Lunch: Tuna salad sandwich on whole grain bread, carrot sticks, and a side of 
hummus
    Snack: Greek yogurt with granola and mixed berries
    Dinner: Grilled steak with mashed sweet potatoes and steamed broccoli
    Snack: Rice cakes with cheese and deli meat
    
    Friday:
    Breakfast: Whole grain waffles with scrambled eggs and turkey bacon
    Snack: Apple slices with cheese
    Lunch: Grilled shrimp with quinoa and steamed vegetables
    Snack: Nuts and dried fruit mix
    Dinner: Pork chops with roasted potatoes and green beans
    Snack: Rice cakes with peanut butter and banana

    Saturday:
    Breakfast: Omelette with cheese, mushrooms, onions, and spinach
    Snack: Rice cakes with nut butter and jelly
    Lunch: Grilled chicken wrap with mixed greens, cherry tomatoes, and avocado
    Snack: Cottage cheese with granola and mixed berries
    Dinner: Beef stir-fry with brown rice and steamed vegetables
    Snack: Rice cakes with cheese and deli meat
    
    Sunday:
    Breakfast: Whole grain French toast with scrambled eggs and turkey bacon
    Snack: Rice cakes with almond butter and honey
    Lunch: Grilled salmon with mixed greens, cherry tomatoes, and quinoa
    Snack: Nuts and dried fruit mix
    Dinner: Baked chicken breast with mashed sweet potatoes and steamed broccoli
    Snack: Rice cakes with peanut butter and banana

    Notes: This meal plan is high in protein and complex carbohydrates, which are important for building muscle mass. It also includes healthy fats, fiber, and a variety of fruits and vegetables to support overall health and wellness. The snacks are designed to be easy and convenient, while still providing the nutrients needed to support muscle growth and recovery.

Nevertheless, keep in mind that a fitness plan can be highly personalized, and it may vary depending on how much time per week you are willing to devote to working out, you food preferences, as well as economic implications. If you would like something more personalized I would be happy to help!