It's not about individual nutrients anymore.
For much of the 20th century, nutrition research focused largely on the health risks and benefits of single nutrients. The findings translated into public health messages telling us to reduce fat; limit cholesterol; increase fiber; get more calcium; take vitamins E, C, and D; and so on. But as scientists learn more, they're finding that the health effects of food likely derive from the synergistic interactions of nutrients and other compounds within and among the foods we eat. This has led to a shift from nutrient-based recommendations toward guidelines based on foods and eating patterns.
There's no single healthy diet. Many eating patterns sustain good health. What they have in common is lots of fruits, vegetables, and whole grains, along with healthy sources of protein and fats. Consistently eating foods like these will help lower your risk for conditions such as heart disease, stroke, diabetes, and certain forms of cancer.
If you'd like to make this largely plant-based approach to eating one of your good-health goals for 2012, here's how to get started.
1. Build a better plate. In the fall of 2011, nutrition experts at the Harvard School of Public Health and colleagues at Harvard Health Publishing unveiled the Healthy Eating Plate (see below), a visual guide to healthful eating that improves on the government's "MyPlate." Both guides are meant to simplify the task of planning healthy meals. The Healthy Eating Plate is made up of one-half vegetables and fruits, one-quarter whole grains, and one-quarter healthy protein. "Whole" and "healthy" are important words here. Refined grains (think white breads, pastas, and rice) have less fiber and fewer nutrients than whole grains, such as whole-wheat bread and brown rice (see No. 4). Healthy proteins include fish, poultry, beans, and nuts — but not red meats or processed meats. Many studies have shown that red meats and especially processed meats are linked with colorectal cancer — and that you can lower your risk for heart disease by replacing either type of meat with healthier protein sources. So eat red meats sparingly (selecting the leanest cuts), and avoid processed meats altogether. Hint: To learn more about the Healthy Eating Plate, go to www.health.harvard.edu/plate.
2. Pile on the vegetables and fruit. Vegetables and fruits are high in fiber and contain many vitamins and minerals as well as hundreds of beneficial plant chemicals (phytochemicals) that you can't get in supplements (see No. 8). Diets rich in vegetables and fruit can benefit the heart by lowering blood pressure, cholesterol levels, and inflammation and improving insulin resistance and blood vessel function. In long-term observational studies, people who eat more fruits and vegetables have a lower risk of heart disease, diabetes, and weight gain, and those who eat more fruit also have a lower risk of stroke. Hint: Fresh fruits and vegetables are great, but don't avoid the frozen kind (or dried fruit or canned fruits and vegetables minus the heavy syrup or salt) when they're more convenient.
3. Go for the good fats. At one time, we were told to eat less fat, but now we know that it's mainly the type of fat that counts. The most beneficial sources are plants and fish. You can help lower "bad" LDL cholesterol by eating mostly polyunsaturated fats (including vegetable oils and omega-3 fatty acids, found in fish, seeds and nuts, and canola oil) and monounsaturated fats (in avocados and many plant-based oils, such as olive oil and canola oil). Saturated fats (found mostly in dairy and meat products) and trans fats (hydrogenated fat found in many fried and baked goods) boost LDL cholesterol and triglycerides, increasing your risk of heart disease. Worse still, trans fats reduce your "good" HDL cholesterol. Hint: As long as you replace bad fats with good ones, you can get up to 35% of your calories from fat.
4. Replace refined grains and potatoes with whole grains. Whole grains retain the bran and germ of the natural grain, providing healthful fiber, vitamins and minerals, antioxidants, and phytochemicals. Many of these substances are removed from refined grains, such as white bread and white rice, and are barely present in starches such as potatoes. Starches and refined carbohydrates are digested quickly, causing surges in insulin and blood sugar, boosting triglycerides, and lowering HDL cholesterol. These changes increase the risk of heart disease and diabetes. The rapid rise and fall of blood sugar and insulin can also make you hungry, raising the risk of weight gain. Potatoes aren't all bad; they're a good source of vitamin C, potassium, and fiber. But eat them only occasionally, in small amounts, and with the skins on (that's where the fiber is). Hint: Be adventurous. In addition to whole wheat and brown rice, try quinoa, millet, farro, and amaranth. Some of these whole grains can be cooked like hot cereal or rice, and some are ground into flour for baking.
"Carb-check" your breads and cereals
Some carbohydrates are good for health and others aren't. The worst carbohydrate sources use highly refined grains and sugars. The best have whole or minimally processed grains. One way to identify a good carb source is to divide the number of grams of carbohydrate per serving by the number of grams of fiber. Aim for less than 10 for breads and under five for cereals.
5. Eliminate liquid sugars. Sugar-sweetened beverages — non-diet sodas, sugary fruit drinks, iced teas with added sugar, and sports drinks — provide calories and little else. There's good evidence that these drinks can raise the threshold for satiety (feeling full), thereby increasing the amount you eat and promoting weight gain. A 2011 Harvard study found that sugar-sweetened beverages were one of the dietary components most strongly linked to long-term weight gain among healthy women and men. What about 100% fruit juice with no added sugar? Even all-natural fruit juice has a lot of calories. The Healthy Eating Plate guidelines suggest you drink no more than one small glass a day (say, 4 to 6 ounces). Hint: Add carbonated water to your "one small glass" for full-glass satisfaction.
6. Drink enough water. Many foods contain water, so you may get enough every day without making a special effort. But it can be helpful to drink water (or another no-calorie liquid, such as black tea, coffee, or carbonated water) with meals or as an alternative to snacking. A reasonable goal is 4 to 6 cups of water a day. Hint: As you add whole grains to your diet, water helps move the fiber smoothly through your digestive tract, reducing the chances of constipation.
7. Learn to like less sodium. The body needs sodium for proper muscle and nerve function and fluid balance, but excessive amounts can increase blood pressure and the risk of heart disease and stroke. The dangers of a salty diet (salt is 40% sodium) are greatest in people over age 50, African Americans, and women. You'll do yourself a favor if you wean your taste buds from a yen for salt. Limit your daily sodium intake to 2,300 milligrams (mg) — the amount in one teaspoonful of salt. If you have high blood pressure or are at risk for it, get no more than 1,500 mg per day. Hint: Most of the sodium Americans consume comes from processed and restaurant foods. Instead, choose fresh, unprocessed foods, and prepare them yourself. Read the nutrition content on labels and make sure that the per-serving sodium content is less than the calories per serving.
8. Rethink supplements. It's best to get your vitamins and minerals from food rather than supplements, but this can be hard, especially if you're cutting calories or your energy needs are low. We showed how to meet almost all your nutrient needs through food alone, even if you're consuming 1,500 calories or less per day (see www.health.harvard.edu/vits). The key is choosing nutrient-dense foods, such as leafy greens, low-fat yogurt, dried beans, whole grains, and salmon. The only problem is vitamin D. Here a supplement is probably a good idea, because it's difficult to get the recommended daily intake (600 to 800 IU) through foods. Hint: You can get enough calcium on a 1,500-calorie-a-day diet by eating low-fat dairy products and nondairy foods such as canned salmon, tofu, sesame seeds, dark leafy greens like collards and kale, and legumes such as pinto and kidney beans.
9. Dine mindfully. Taking time to savor your food not only makes eating more enjoyable, it can also help control your appetite. Your sense of fullness and satisfaction depends on hormonal signals from your digestive tract. If you eat too quickly, your brain may not receive the signals that say you're full. Try putting down your fork between bites and chewing more slowly. Tune in to your food's aroma, taste, and texture, and stop eating when you feel full. Some small studies suggest that this approach may help some people make healthier food choices. Hint: To start, try taking one mindful bite at the beginning of each meal — a sort of eating speed bump.
10. Keep alcohol under control. Many studies link moderate alcohol consumption (for women, no more than one drink per day) to heart benefits, including a reduced risk of heart attack, increases in "good" HDL cholesterol, and reduced risk for type 2 diabetes, gallstones, and dementia. One drink per day also slightly increases your risk for breast cancer, and the risk increases steadily the more alcohol you consume. There are plenty of other ways to get heart benefits, so if you don't like alcohol, don't have it. But if you enjoy an occasional cocktail or a glass of wine with dinner, you need to weigh the risks and benefits in light of your own situation. Hint: If you find that one drink often turns into two or more, consider quitting or getting help to cut back. For help, go to http://rethinkingdrinking.niaaa.nih.gov.)
11. Eat breakfast. It's easy to skip breakfast when you're in a rush, aren't hungry, or want to cut calories. But a healthy morning meal makes for smaller rises in blood sugar and insulin throughout the day, which can lower your risk of overeating and impulse snacking. (Eating breakfast every day is one characteristic common to participants in the National Weight Control Registry, who've lost at least 30 pounds and kept the weight off longer than a year.) Hint: A healthy, balanced breakfast is moderate in size and includes healthy protein, whole-grain carbohydrates, and fruit — for example, an egg, whole-wheat toast, and strawberries. If you like cereal, have whole-grain cereal with fruit and low-fat yogurt or milk.
12. Plan for a snack attack. Snacking isn't an essential part of a healthy eating plan, but try telling that to a rumbling stomach at midafternoon. A healthy snack can boost energy levels by stabilizing blood sugar while giving you an added dose of healthful nutrients. But unplanned, impulsive snacking often takes the form of cookies, chips, or candy bars. So prepare healthy snacks ahead of time, and keep them handy at home or in your office. Limit calories to about 100 to 150 per snack. Good choices include a small bunch of grapes, a banana, or other fruit; a handful of unsalted nuts or sunflower seeds; and plain nonfat yogurt with a few raspberries or strawberries tossed in. Hint: Before giving in to a snack attack, drink an 8-ounce glass of water and wait 10 to 15 minutes to see if you're still hungry.