Instead of shopping, use your time and energy to plan meals and write out a grocery list. Enlist someone to do the shopping for you. In some parts of the country, grocers are reviving the idea of home delivery, which would relieve you of the physical exertion of this task.
If you do shop for food yourself, consider shopping in smaller stores (this is true for hardware, clothing, and other types of purchases, too); you'll be able to park closer, shop faster and eliminate the temptation to shop until you drop.
When you cook, plan ahead. If possible, have someone get everything you'll need (the big bowl, the electric mixer, the ingredients) out and on the counter for you. An indispensable tool in the kitchen is a high stool or chair at a comfortable level for your work surface. A bar stool with a back is very nice for this purpose.
Take advantage of morning, when you are most likely to feel alert. You may want to make breakfast your main meal of the day. Your appetite may also be better in the morning.
If possible, divide tasks into parts that can be done between rest periods. For example, run vegetables in the food processor right after breakfast and store them, covered, in the refrigerator until ready to use. A slow-cooking crockpot is an excellent tool, especially if your fatigue typically worsens in the afternoon. (Another advantage of crockpots is that the cooking odors stay inside the pot, which will be a relief if odors have become a problem for you).
If you are working outside the home during your recuperation, take advantage of weekends for cooking. Would you normally go to a cafeteria at lunch time? If the food selections are healthful (i.e., not laden with fat), consider bringing a sandwich for lunch (which is very easy to fix) and buying a carry-home supper from the cafeteria.
When cooking, choose the part of the meal preparation that's interesting to you, and do that part. Leave the rest to another family member or use a commercial product. Spaghetti sauce from a bottle is a perfectly acceptable alternative to made-from-scratch, as are canned stews, soups, and frozen dinners and pizzas - as long as the fat content is low. Keep in mind that many of the products are high in sodium, so if you are on a low-sodium diet, these may not be appropriate for you. Combine canned, low-fat, low-salt soup with 3 ounces of chicken or fish and ladle over toast for a quick and easy dinner. Accompany these quick dinners with skim milk and fresh fruit.
Steer clear of complicated menus. A roasted whole chicken is much simpler than a fricassee and will yield leftovers for additional meals.
If you feel you can handle it, make a large batch of a single dish and freeze the extras. Instead of cooking just a portion of rice, spaghetti, macaroni, or noodles, it takes just a tiny bit more energy to cook a lot, and these batches freeze exceptionally well in sealable plastic bags.
Check into the availability of Meals-on-Wheels services in your area.
Eat small, nutritious snacks all day. Eating six small meals will take less effort and time to prepare and eat.