The basic principles of good diets are so simple that I can summarize them in just ten words: eat less, move more, eat lots of fruits and vegetables. For additional clarification, a five-word modifier helps: go easy on junk foods. Follow these precepts and you will go a long way toward preventing the major diseases of our overfed society—coronary heart disease, certain cancers, diabetes, stroke, osteoporosis, and a host of others.... These precepts constitute the bottom line of what seem to be the far more complicated dietary recommendations of many health organizations and national and international governments—the forty-one “key recommendations” of the 2005 Dietary Guidelines, for example. ... Although you may feel as though advice about nutrition is constantly changing, the basic ideas behind my four precepts have not changed in half a century. And they leave plenty of room for enjoying the pleasures of food.[23]:22
Supplements can't substitute for a healthy diet, which supplies other potentially beneficial compounds besides vitamins and minerals. Foods also provide the synergy that many nutrients require to be efficiently used in the body. Still, for many people a basic multivitamin/mineral pill can provide some of the nutrients they may fall short on. Certain people may also need supplements of folic acid, vitamin B12, calcium, and vitamin D (see next slide).
These support bone health and have other possible benefits. Dairy products are the best sources of calcium, but you can also get it from fortified foods as well as canned salmon, sardines, dark leafy greens, and most tofu. If you can’t get the recommended 1,000 to 1,200 milligrams a day from food, take a calcium supplement. It’s hard to consume enough vitamin D from foods (the RDA is 600 to 800 IU a day, though other experts advise more). Thus, many people—especially those who are over 60, live at northern latitudes, or have darker skin—should consider taking a supplement.
Blueberries are lousy with antioxidants, satiating fiber, potassium, and more, and according to researchers at the University of Michigan, the colorful fruits may also encourage weight loss. In a study of laboratory rats, scientists found that after 90 days the rats who consumed blueberry-enriched powder as 2 percent of their diet had less abdominal fat, lower triglycerides, lower cholesterol, and improved fasting glucose and insulin sensitivity, than the rats who didn’t consume any blueberry-enriched powder.
For a 2,000-calorie daily diet, aim for 2½ cups of vegetables and 2 cups of fruit a day. If you consume more calories, aim for more produce; if you consume fewer calories, you can eat less. Include green, orange, red, blue/purple, and yellow vegetables and fruits. In addition to the fiber, the nutrients and phytochemicals in these foods may help protect against certain types of cancer and other diseases. Legumes, rich in fiber, can count as vegetables (though they have more calories than most vegetables). For more fiber, choose whole fruits over juice.