Variety, nutrition and calories--all are necessary for a working man's sack lunch. The best guidelines for sack lunches might be those required for wildland firefighters. Each firefighter's sack lunch must include a main protein item equivalent to 3.5 oz. of meat or cheese or a combination, a second item that's typically another sandwich or a 400-calorie energy bar, one fresh fruit, a 200-calorie dried fruit item and two snacks of 300 calories each. Adapting a firefighter's menu to suit your sack lunch is easy.
Protein and carbohydrates
Sandwiches containing meats and cheeses are a standard sack lunch feature, but you can use alternative protein items for variety. Pasties or pocket pies made with beef and onions are hearty and nutritious. Burritos transport well and are quickly heated, or can be eaten cold. Try a container of chicken salad or pork/pasta salad. Pack a make-your-own sandwich with pita bread and canned tuna. Fried or baked chicken, or cold pork chops, add variety and nutrition for a week's worth of sack lunches. For safety, make sure protein items are well chilled, and pack condiments such as mayonnaise or dressing separately.
Fruits and vegetables
Fresh fruits and vegetables don't have to be boring. Quartered bell peppers or a container of cherry tomatoes provide a good alternative to apples and oranges. Try a container of fruit salad, or a zip bag of pasta salad with black olives and marinated artichoke hearts. Mix chopped celery with chopped apples, raisins and smoked salmon. A sandwich bag filled with carrots and celery is nutritious, but not something a working man wants to eat every day; provide variety in the sack lunch with items such as containers of pickles or pepperoncini, bagged salted nuts or packages of dried fruit.
Snacks
A bag of potato chips in a sack lunch may please little kids, but a working man needs a little more variety and a lot more nutrition to get through the day. Boiled eggs or canned fish will provide extra protein; both make for a tasty snack. Cold pizza keeps well and offers extra nutrition and calories. Cheese and crackers is a good alternative, and jerky with string cheese adds protein. Try a bagel and cream cheese with smoked trout or a thin-sliced smoked pork chop.
Desserts
Though there's nothing wrong with a bag of chocolate chip cookies, dessert items in a sack lunch can be far more nutritious and satisfying. A container of applesauce cake or homemade brownies will better finish off a working man's lunch. Though candy bars provide a fix for a sweet tooth, homemade blueberry muffins are more nutritious. Make a dozen little pocket pies--stuffed with apples or peaches or blackberries--on the weekend, then freeze them and include one every few days for a fun finish to a sack lunch.