Nutrients provide energy or nourish your body in some way. A healthy diet provides all of the nutrients your body needs without excessive calories. The types of sugar you eat, your balance of calories and absorption of minerals are key elements that determine whether you get the nutrients you need.
Carbohydrates are Essential
Carbohydrates are your body’s main energy source. During digestion carbs break down into glucose, which is pulled into cells with the help of insulin. Most of your calories, 45 to 65 percent, should come from carbohydrates, which provide four calories per gram. If you follow a 2,000-calorie diet, you should consume 225 to 325 grams of carbs each day, according to the USDA’s Dietary Guidelines for Americans 2010.
Your Body Stores Carbohydrates
Your body uses the carbohydrates it needs right away and then converts the rest into glycogen, a complex type of polysaccharide carbohydrate. When carbohydrates are not available, glycogen is quickly converted to glucose for immediate energy. Typically your liver and muscles store enough glycogen to fuel up to two hours of vigorous activity.
Fiber Is a Carbohydrate
Fiber is a type of complex carbohydrate, but it does not break down into glucose and therefore does not provide calories. Only plant foods provide fiber. Soluble fiber is the soft part of fruits, vegetables and certain grains that slows digestion. Insoluble fiber, which is the tough skin of plant foods that is difficult to chew, speeds up digestion and relieves constipation. Most fibrous foods have some of each type of fiber.
Some Fats Are Good
All fats have nine calories per gram, but not all fats are created equal. Monounsaturated and polyunsaturated fats, from vegetable oils, avocados, nuts and cold-water fish, protect your heart and can lower your risk of type 2 diabetes. Avoid harmful saturated and trans fats that can damage your heart. Keep your fat intake to 20 to 35 percent of your total calories, which amounts to 44 to 77 grams for a 2,000-calorie diet.
Protein Provides Energy
Protein is a structural component of muscle tissues, organs and cell walls, but it also acts as a backup source of energy when carbohydrate and fat are not available. Like carbohydrates, protein has four calories per gram. Between 10 to 35 percent of your calories should come from protein, depending on your activity level. If you follow a 2,000-calorie diet, you need 50 to 175 grams of protein each day.
Caloric Imbalance Equals Weight Gain
It takes 3,500 calories to equal 1 pound of body weight. Gaining weight means that you are consuming more calories than your body is able to burn. Cutting just 250 calories from your daily diet can result in 1 pound of weight loss in as little as two weeks.
Not All Sugars Are Bad
Sugar has a bad reputation, but not all sugars are harmful. Fruit has sugar in the form of fructose and milk has sugar as lactose. These naturally occurring sugars from whole foods are a part of a healthy diet. The sugars you need to avoid are sucrose, dextrose, maltose or other added sweeteners. These types of sugars are added to processed foods, which are often low in nutrients.
Plant Calcium Absorbs Poorly
Dark green vegetables like kale, spinach and broccoli are high in calcium, but the calcium has poor bioavailability. These foods contain phytic acid and oxalic acid that inhibit some of the calcium absorption. You should not rely solely on plant foods to meet your calcium intake. Dairy foods are some of your best options for highly bioavailable calcium.
Sodium Is Not Always Your Enemy
You need some sodium in your diet to maintain fluid balance, an essential function of normal heart function. Problems with sodium occur when you consume too much. Excessive sodium intake causes your body to retain water, making your heart work harder. Over time this may put you at risk for heart disease. Protect your heart by keeping your sodium intake to less than 1,500 milligrams per day.
Not all Iron is Equal
Iron from dark green vegetables, lentils, beans and other plant foods is called nonheme iron. It is harder to absorb than heme iron from animal foods. As with calcium, certain components in plants inhibit some of the nonheme iron absorption. Including vitamin C-rich foods such as strawberries, oranges and broccoli in your diet helps your body absorb nonheme iron more efficiently.