Variety maximizes whole food health. Variety in any diet also makes the diet more sustainable for the long term. A healthy whole food diet is different from most diets that concentrate on weight loss or muscle-mass gain or some other tiny slice of overall health because the only restrictions are against highly refined foods.
You can eat as much fruit as you want as long as it is not out of a can packed with added sugar or high fructose corn syrup. Eat as many vegetables as appeal to you, just avoid canned veggies with extra salt and preservatives and frozen vegetables in any kind of sauce(almost all commercial sauces will have added salt and sugar as well as coloring and preservatives). Eat and drink dairy but do your best to stick to grass fed sources and to raw milk cheeses. Eggs and poultry should be pasture raised so that the animals ate a natural diet and produced the full range of vitamins and minerals and the proper ratio of omega-3/omega-6 fats. Beef should always be grass fed(not only much healthier but almost eliminates any possibility of mad cow disease). Eat whole grains(brown instead of white rice, hulled instead of pearled barley) to increase nutrition and reduce inflammation at the same time.
Add variety by switching the primary vegetables of meals from day to day. If you want to feature roasted zucchini and crook–neck squash on Monday, Roast twice as much as needed and save the extra for Wednesday or Thursday. Make steamed carrots, golden beets and parsnips for Tuesday but cook enough to have the leftovers on Friday. Make rigatoni pasta with fresh tomato sauce to go with Monday’s squash and use the extra to make a cold pasta & raw vegetable salad for lunch on Tuesday and Thursday. Raw broccoli, cauliflower, carrot and celery with baba ganoush and hummus for lunch on Monday? Stir fry the rest of the veggies for dinner later in the week. Starting to get the idea?
Try to eat a combination of raw and cooked vegetables every day. Do this on the same plate when practical. The variety of flavors and textures adds a lot of interest to a meal that is just not present with fast food or commercial frozen dinners. Strive for a rainbow of colors on your plates throughout the day and the week. Eating this way ensures that your body is getting the widest possible range of nutrients. This is what is most important for maintaining health.
I feel strongly that animal products have a place in any healthy diet. We evolved as omnivores and meat, dairy and eggs are the easiest way to satisfy the body’s need for complete protein. I also believe it is possible, but not easy, to maintain health on a vegetarian or fully vegan diet. Long term sustainability is more difficult because of reduced variety and the increased difficulty of ensuring complete nutrition. Vitamin and mineral supplements have only existed for 100 years and should not be necessary for optimum health if we are eating the diet we evolved to eat.
Vegetables and plants always make up the largest part of any day’s or week’s food by a large margin. Animals can run away from people that want to eat them and plants cannot. It makes sense to me that our ancestors would have eaten mostly plants simply because plants would have been much easier to find and prepare.
So eat a lot of different stuff. Keep it interesting. Challenge your flavor palette with new things regularly. To stay healthy, this has to last for the rest of your life. If you want it to be a long life that you can enjoy, you need to be healthy.