 In my book, How Not to Die, I suggest we try to center our diets around whole-plant foods, but some plants are healthier than others. For example, you can apparently live extended periods eating practically nothing but white potatoes that would, by definition, be a whole-food-plant-based diet, but not a very healthy one. All-plant foods are not created equal. The more I researched over the years, the more I've come to realize that healthy foods are not necessarily interchangeable. Some foods and food groups have special nutrients not found in abundance elsewhere. For example, sulforaphane, the amazing liver enzyme detox-boosting compound, is derived nearly exclusively from cruciferous vegetables. You could eat tons of other kinds of greens and vegetables on a given day and get no appreciable sulforaphane if you didn't eat something cruciferous. It's the same with flax seeds and the anti-cancer lignan compounds. Flax may average 100 times more lignans than other foods. And mushrooms aren't even plants at all. They belong to an entirely different biological classification and may contain nutrients like ergothionine, not made anywhere in the plant kingdom. So technically, maybe I should be referring to a whole-food-plant and fungus-based diet, but that just sounds kind of gross. It seems like every time I come home from the medical library buzzing with some exciting new data, my family rolls their eyes, sighs, and asks, what can't we eat now? Or they'll say, wait a second, why does everything seem to have parsley in it all of a sudden or something? They're very tolerant. As the list of foods I tried to fit into my daily diet grew, I made a checklist and had it up on a little dry erase board on the fridge and we'd make a game out of ticking off the boxes. This evolved into my daily dozen. The checklist of all the things I tried to fit into my daily routine. By beans, I mean legumes, which also include split peas, chickpeas, and lentils. You know, while eating a bowl of pea soup or dipping carrots into hummus may not seem like eating beans, it certainly counts. We're just trying to get three servings a day. Serving is defined as a quarter of cup of hummus or bean dip, half cup of cooked beans, split peas, lentils, tofu, or tempeh, or a full cup of fresh peas or sprouted lentils. Though peanuts are technically legumes, nutritionally I've grouped them in the nuts category, just as I would shunt green beans, snap peas, and string beans into the other vegetables category. A serving of berries is a half cup of fresh or frozen, or quarter cup of dried. While biologically speaking, avocados, bananas, and even watermelons are technically berries, I'm using the colloquial term for any small edible fruit, which is why I include cumquats and grapes and raisins, as well as fruits that are typically thought of as berries, but actually technically orange, such as blackberries, cherries, mulberries, raspberries, and strawberries. For other fruits, a serving is a medium-sized fruit, a cup of cut-up fruit, or a quarter cup of dried fruit. Again, I'm using the colloquial rather than the botanical definition, so I place tomatoes in the other vegetables group. Even cruciferous vegetables include broccoli, cabbage, collards, and kale. I recommend at least one serving a day, typically a half cup, and at least two additional servings of greens a day, cruciferous or otherwise. Serving sizes for other greens and vegetables are a cup for raw, leafy vegetables, a half cup for other raw or cooked non-leafy vegetables, and a quarter cup for dried mushrooms. Everyone should try to incorporate one tablespoon of ground flax seeds into their daily diet, in addition to a serving of nuts or other seeds. A quarter cup of nuts is considered a serving, or two tablespoons of nut or seed butters, including peanut butter. Chestnuts and coconuts, though, don't nutritionally count as nuts. I also recommend one quarter teaspoon a day of the spice turmeric, along with any other salt-free herbs and spices you may enjoy. A serving of whole greens can be considered a half cup of hot cereal, such as oatmeal, cooked whole grains, or so-called pseudo grains, like amaranth, buckwheat, and quinoa, or a half cup of cooked pasta, or corn kernels, a cup of ready-to-eat cold cereal, one tortilla or slice of bread, half a bagel or English muffin, or three cups of air-popped popcorn. The serving size in the beverage category is one glass, 12 ounces, and the recommended five glasses a day is in addition to the water you get naturally from the foods in your diet. I explain my rationale in my video, How Many Glasses of Water Should We Drink a Day? Finally, I advise one daily serving of exercise, which can be split up over the day. I recommend 90 minutes of moderate intensity activity each day, such as brisk 4 mph walking, or 40 minutes of vigorous activity, such as jogging or active sports each day. I explain my reasoning for that in my video, How Much Should You Exercise? This may all sound like a lot of boxes to check, but it's easy to knock off a bunch at a time. One simple peanut butter banana sandwich, and you just checked our four boxes, or imagine sitting down to a big salad, two cups of spinach, a handful of arugula, a handful of walnuts, a half cup of chickpeas, a half cup of red bell pepper, and a small tomato. You just knocked out seven boxes in one dish. Sprinkle on your flax at a handful of goji berries and enjoy it with a glass of water and fruit for dessert, and you just wiped out nearly half your daily check boxes in a single meal. And then if you just eat it on your treadmill, just kidding. Do I check off each glass of water I drink? No. In fact, I don't even use the checklist anymore. I just used it initially as a tool to get me into a routine. You know, whenever I was sitting down to a meal, I would ask myself, could I add greens to this? Could I add beans to this? I mean, I always have an open can of beans in the fridge. Can I sprinkle on some flags or pumpkin seeds or maybe some dried fruit? The checklist just got me into the habit of thinking, how can I make this meal even healthier? I also found the checklist helped with grocery shopping, although I always keep bags of frozen berries and greens in the freezer. And if I'm at the store and want to buy fresh produce for the week, then it helps me figure out how much kale or blueberries I need. The checklist also helps me picture what a meal might look like. I mean, looking over the checklist, you see that there are three servings each of beans, fruits, and whole grains, and about twice as many vegetables in total than any other component. So glancing at my plate, I can imagine one quarter of it filled with grains, one quarter with legumes, and a half of the plate filled with vegetables, along with maybe like a side salad and fruit for dessert. I happen to like one bowl of meals where everything's mixed together, but the checklist still helps me to visualize, right? Instead of a big bowl of spaghetti with some veggies and lentils on top, I think of a big bowl of vegetables with some pasta and lentils mixed in. Instead of a big plate of quinoa with some stir-fried vegetables on top, I picture a meal that's mostly vegetables, and oh look, there are some quinoa and beans in there too. But there's no need to be obsessive about the Daily Dozen. You know, on hectic travel days, when I burn through my snacks, you know, stuck in some airport food court somewhere, sometimes I'm lucky if I even hit a quarter of my goals, right? If you eat poorly one day, just try to eat better the next. To help track your progress, volunteers created Dr. Gregor's Daily Dozen apps for both iPhone and Android. You can download and use them both for free, no ads, no cost. My hope is that the checklist will just serve as a helpful reminder to try to eat a variety of some of the healthiest foods every day.