I rarely follow a set diet but I always try to stick to the same amounts of protein, carbohydrates and fats per meal. Once you know how many calories, carbohydrates, protein, and fats are in certain foods that you eat, it becomes easier to manage a good 'on the go' diet.

If dieting, I spend 4/5 days a week on my low carb days, and 2/3 days a week using my high carb days.
If I am trying to slowly gain muscle and at the same trying to keep lean, I will spend 4-5 days a week on my high carb days and 2-3 days using my low carb days.

With that said, here is a high carb/low carb sample diet:

Meal 1: 1 whole egg, 5 whites omelette with onions & tomatoes or Whey protein shake. A large serving of oatmeal

Meal 2: Chicken or tuna on wheat bread, fruit

Meal 3: Salmon/chicken with large serving of wholegrain rice or A large serving of oatmeal with a shake

Meal 4: Whey protein shake, large serving oatmeal

Meal 5: Chicken, steak or fish with baked potato, large serving of wholegrain rice or potatoes

Meal 6: Protein shake, small serving oatmeal (1.5-2 hours before bed)

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Meal 1: 1 whole egg, 5 egg whites omelette with onions & tomatoes or whey protein shake

Meal 2: Can of tuna, broccoli (if possible), rice cakes with natural peanut butter

Meal 3: Salmon or chicken with green vegetables or salad, light balsamic vinaigrette

Meal 4: 5-6 egg white omelette or protein shake

Meal 5: Chicken or steak with green vegetables or salad, light balsamic dressing, rice cakes with natural peanut butter

Meal 6: Protein shake