hen it comes to understanding the principles of good nutrition, it often seems like there is more fiction than fact floating around in the media. Nutrition is a science, and we nutrition experts and researchers do not arrive at facts easily. Nutrition information becomes fact only when it can be observed and validated by several different rigorously designed research studies, not when a celebrity tests out a diet in his or her own kitchen and reports the results. March is National Nutrition Month and this year's theme is Nutrition: It's a Matter of Fact. The following are some important nutritional facts that I want to emphasize this National Nutrition Month:

Fact: All fats are not "bad." Some types of fats are important for health; it's a matter of eating them in the right balance. Minimize saturated fats and avoid trans fats and emphasize monounsaturated fats and omega-3 fats (a type of polyunsaturated fat) in your food choices. Saturated fats are found in butter, cream, whole milk and yogurt, red meat, poultry skin and cheese, while trans fats are in deep fried foods as well as many baked goods that use margarine or shortening, including cookies, cakes, crackers, breads, muffins and pies. When ingredient lists are available, read them and look for the words "partially hydrogenated oil" to help weed out trans fats. Replace unhealthy fats with health-promoting monounsaturated fats mainly from extra virgin first cold-pressed olive oil and nuts, seeds and avocados. When it comes to polyunsaturated fats, try to balance omega 3s with other polyunsaturated fats from soybean, sunflower, safflower, corn, sesame and peanut oils. Omega-3 fatty acids are mostly found in fatty fish, like salmon, anchovies, black cod and tuna, and to a lesser degree in flax seeds, canola oil and fortified foods, such as eggs. Aim to eat roughly twice as much monounsaturated fat as you do polyunsaturated and saturated fat.

Fact: Carbohydrates should be chosen carefully. Carbohydrates are important sources of energy and they are necessary for many of the metabolic processes that take place in our bodies, but some fuel us better than others. When choosing starches, pick whole, intact grains--like oats, barley, brown rice, wild rice and quinoa--over grains that are processed into flour to make bread, pasta, crackers, cookies and cereals. Minimally processed carbs can aid in weight and blood sugar control, while highly processed carbs can have the opposite effect. Whole grains are not always an option, especially when you are eating at a restaurant, but starchy vegetables, including corn, sweet potatoes, baby potatoes, winter squashes and peas, can stand in for grains at some meals. Try ordering one of these vegetables instead of the usual side dishes of white rice, French fries, mashed potatoes or pasta that are usually on the menu.

Fact: Protein is an important component of each meal, but we don't need as much as we think we do. Most of us tend to make it the center of our meals, but it should only be a small part of our plates, more of a side dish than a centerpiece. Protein is essential for health and for a healthy immune system and is also important for weight control because it helps us feel satisfied. Include some protein with each meal and snack to maximize feeling full for several hours. To minimize saturated fats and boost fiber intake, try occasionally substituting plant proteins such as beans, lentils, nuts, seeds, tofu and soybeans for animal proteins.

Fact: We need between nine and eleven servings of vegetables and fruit a day. A diet that meets your produce goals can help lower blood pressure, cholesterol levels and weight. Eating more produce is also associated with lower risks for stroke, heart disease, type-2 diabetes, certain cancers, age-related macular degeneration and osteoporosis. Fruit and vegetables are low in calories, high in nutrients, and relatively filling due to their fiber content, so eating more of them should help you reach a healthy weight since they will displace other foods in your diet that are more caloric and less nutritious.

Fact: Calories count. Most people have no idea how many calories they need or consume each day. In general, adults' calorie requirements range between 1,600 and 2,400 calories, depending on their sex, body size, age and activity level. It's very simple: eating more than you require can lead to weight gain and eating less than you require can lead to weight loss. You often see 2,000 calories listed as daily reference figures, since it is considered the average calorie need for most adults. If you figure that your daily need is 2000 calories, then you can divide your meals and snacks the following way: breakfast: 600 calories; morning snack: 100 calories; lunch: 600 calories; afternoon snack: 100 calories; dinner: 600 calories. If you are working to lose weight, you may want to try eating more calories at the beginning of the day as follows: breakfast: 700 calories; morning snack: 100 calories; lunch: 600 calories; afternoon snack: 100 calories; dinner: 500 calories. When choosing what to eat, always keep the following in mind: larger portions have more calories than smaller portions of the same food and large portions encourage you to eat more, so always try to put smaller portions on your plate to save calories and prevent weight gain.

Fact: For balanced nutrition at lunch and dinner, your plate should be mostly vegetables and fruit. Fill half of your plate with produce, a quarter with intact whole grains or starchy vegetables and a quarter with protein.

Fact: Eating a certain type of fat can make you store belly fat, while eating another type can help you lose fat around your belly. Trans fats tell your body to store fat deep within your abdomen, which increases inflammation. Trading in trans fats for monounsaturated fats can help you lose some of that dangerous abdominal fat.

Fact: Chronic inflammation can increase your risk of obesity, diabetes, insulin resistance, certain cancers, Alzheimer's disease, high blood pressure and heart disease. Eating an anti-inflammatory diet (see January 2008 Nutrition Notes), combined with exercise and abstinance from smoking, can help reduce chronic inflammation and its related conditions.

Fact: Eating antioxidants in foods is more beneficial than taking them in supplement form. Nature makes plants in unique packages that contain complex combinations of nutrients that can't be replicated in pills. Furthermore, separating these naturally occurring ingredients from one another may decrease or eliminate their health benefits. To reap the benefits of antioxidants in your diet, eat a rainbow of colorful foods, especially plant foods.

Fact: You don't need to drink eight glasses of water a day, but if you're not meeting your fluid needs with water, what are you drinking instead? Water should be your top beverage choice since it makes up about 50-75% of our body weight. Unsweetened white, green, black or red tea can be a healthy alternative to water, as can a cup of unsweetened 100% fruit juice, nonfat milk or soy milk a day. Soft drinks, both diet and regular, should be eliminated from your regular diet since they are associated with metabolic syndrome and weak bones.

March is National Nutrition Month, but it's important to have good nutrition in mind all year 'round. We eat every day, so you need to know your nutrition facts in order to make healthy choices at most of your meals. The more you know about nutrition, the more you can practice healthful eating. The better you eat, the healthier you will be-and that's a fact!