Nutrition guidelines are generally geared toward exercise, but...
Many survivalists tend to focus on defending against external threats — natural disasters, civil unrest, terrorist attacks, car crashes, and home invasions. These are all valid dangers to prepare for, but we also shouldn't overlook internal threats to our well-being. This is why we frequently emphasize physical fitness, mental fortitude, and a healthy diet.
Anyone who spends all day sitting on the couch slowly clogging his or her arteries with junk food isn't going to fare well in a survival scenario. Similarly, if you think you're going to subsist on nothing but a stockpile of protein bars and water, you may end up seriously unhealthy. A balanced diet is key to good nutrition, and good nutrition is key to long-term survival.
Fresh fruits and vegetables are an ideal way to supplement your diet, and much of this produce can be grown in a backyard garden or with an indoor hydroponic setup. If neither of these options is viable, you can still stockpile shelf-stable canned, dehydrated, or freeze-dried produce. Additional processing extends shelf life, but also reduces nutrient content, so you can find the balance that fits your needs.
The following infographic from Rockwell Nutrition shows scientifically-supported health benefits of various fruits and vegetables, and categorizes them by color. These tips can help you decide which items to grow at home in your garden, or the produce you pick up on your next trip to the grocery store. Click here to download a full-size version of this graphic.