Fruits: This is stating the obvious, but apples, bananas, peaches, grapes, and other fruits are portable and convenient. Be careful with dried fruit however as they can be very high in sugar.
Nuts: Nuts are very nutritionally rich foods and provide healthy fats and protein. They are good for a low carbohydrate snack, but similar to dried fruit, they can be easy to overeat. Avoid nuts that contain large amounts of unnatural flavorings, oils, etc. and instead opt for raw nuts or dry roasted nuts. Even better, soak raw nuts overnight, and then let them dry to sprout them for even better nutrition and digestion.
Vegetables: Like raw fruits and nuts, raw vegetables are about as simple and easy as it gets when it comes to quick food options. Things like celery (may add almond or nut butters), carrot slices, cherry tomatoes, cucumber, and snap peas can all be eaten on their own or combined in a large container (prepare in bulk) and stored ready to be put in a smaller container to for on the go.
