Drinking enough water can help you stay slim, too. Research from the American Chemical Society in Boston found that having two 8-ounce glasses of water before a meal while also reducing portion sizes could help you lose weight and keep it off. Not to mention, water fills you up, curbing your appetite: "In addition to slightly boosting your metabolism, drinking water before meals has been shown to help you eat less without trying," says Sass.
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.