Make sure you carry enough fluids including water to keep yourself well-hydrated throughout the day. Keep some buttermilk with added salt if you sweat alot. Keep whole wheat sandwiches with raw vegetables like grated carrots, salad leaves, cucumber slices and tomatoes as fillings. You can also carry some fruits like apples, oranges, guava, grapes, plums and peaches which can be eaten without peeling and slicing. You can keep a box with sprouted grams salad and pancakes made with less oil using a non-stick pan. Mix bran into the batter of pancakes and add some vegetables like tomatoes, onions, green chillies and coriander leaves (cilantro) or other herbs from the top while cooking. Cook both sides well and keep them for your lunch. You can also prepare healthy pasta dishes with lots of veggies and low fat pasta sauces. Use whole grain pasta instead of refined ones and cook in less oil, Use healthier cooking oils like olive oil, canola oil. Hope these suggestions will be helpful.