The food we consume directly affects our state of health. Without an adequate supply of the nutrients that our bodies need to function, we would soon succumb to a plethora of illnesses. This is to be expected, because our bodies are complex biological systems that require a wide variety of both macronutrients and micronutrients to perform at its peak.
Deficiencies of nutrients cause illnesses like beriberi, a deficiency of thiamine (vitamin B1), or scurvy a deficiency of vitamin C. At the other end of the spectrum, too much nutrition can cause obesity and its related pathologies, like metabolic syndrome, insulin resistance, and diabetes. In order to avoid these maladies, therefore, it’s crucial to adhere to a balanced diet and healthy eating habits, one that is varied and in the right amount to maintain a healthy weight. We can achieve this by eating foods from all the major five food groups in the right portions: fruits, vegetables, grains, dairy, proteins, and healthy fats. Any healthy diet should limit the amount of fat to 10% of calories, added sugars to 10% of calories, and sodium intake to less than 2.3 grams.
All types of fruits are a healthy source of minerals, vitamins, carbohydrates and fiber. Fruits should be consumed whole as often as possible as the skins contain high concentrations of fiber, vitamins, minerals, and antioxidants, along with other nutrients. Fruits can be sourced as fresh, canned, dried, or frozen. 100% fruit juices can be used as an alternate source of fruits in the diet, but avoid any fruit source containing added sugars. Fruits come in a variety of shapes and colors, and the nutrients they contain are as diverse as the differences in the fruits themselves.
Vegetables come in a variety of colors as well, and like fruits, the nutrient content of vegetables varies from vegetable to vegetable. Green leafy vegetables are an excellent source of vitamin K and calcium. Red and orange vegetables are a good source of vitamin A. Some vegetables that contain high levels of vitamin A include carrots, squash, and sweet potatoes. Tomatoes are a good source of vitamins A, C, K, and potassium and lycopene, an antioxidant that is important for heart health. Studies have shown that consuming a diet rich in tomatoes and tomato products reduces the risk of heart disease.
Grains include wheat, oats, barley, rice, corn, quinoa, and bulgur, which can be consumed in breakfast cereals, breads, pasta or cookies. They can be consumed as whole grains in which the bran and the germ are preserved or as refined grains from which these have been removed. The bran, which is the fibrous outer layer of the grain, and the germ, which is the innermost part of the grain from which growth occurs, contain the highest concentration of nutrients. They contain vitamin B, iron, copper, zinc, magnesium, antioxidants, and phytochemicals. For that reason, we should consume at least half of our daily grains as whole grains. Sources of whole grains include whole-wheat bread, whole-wheat pasta, and brown rice.
Proteins are essential for building and repair of the tissues. We get protein in our diets from meats, beans, peas, lentils, nuts, seeds, soy products, and eggs. We should choose lean cuts of meat to limit the amount of saturated fat in the diet. Saturated fat can raise the blood cholesterol level, leading to blocked arteries, which increases the risk of heart attacks, blood clots, strokes, and poor circulation. Poultry should have the skin removed to decrease cholesterol intake. Red meat and processed meats should be limited, as it is believed even small quantities of these can increase the risk of heart disease, diabetes, colon cancer, and weight gain. A healthy diet includes a variety of lean meats and at least 8 oz of fish weekly. Fish contain ῳ-3 fatty acids that have been shown to protect against heart disease and may even slow the progression of heart disease in those already having it. People who do not eat meat should eat more beans, peas, and lentils to supplement their protein intake.
Fat-free or low-fat dairy should be included in a healthy diet. Dairy is a good source of vitamin D, calcium, and potassium. Calcium and vitamin D are important for strong healthy bones. Dairy nutrients can be consumed in milk, yogurt, and cheeses, although the low-fat, unsweetened varieties are recommended. For people who cannot tolerate dairy or choose not to use dairy, fortified soy milk is a suitable substitute, as its nutrient content is similar to that of milk. Other milk substitutes made from almond, rice, or coconut have not been found, in general, to be an adequate substitute for milk.
All fats are not created equal. Fats consumed as a part of a healthy diet should be healthy fats. Healthy fats include the mono and polyunsaturated oils such as canola, avocado, and olive. Oils from palm and coconut oil are high in saturated fat, and are not recommended as a part of a healthy diet. Saturated fats, as mentioned above, have been found to raise blood cholesterol levels, as do trans-fats, and these have been linked to heart disease. Poly-unsaturated fats, on the other hand, are associated with a decreased incidence of heart disease.
The food we eat forms the foundation of a healthy lifestyle. The key thing to remember is that a healthy, balanced diet focuses on both the quality and quantity of food we consume. Because the caloric needs of our bodies depend on metabolic rates, activity levels, and body size, the best way to monitor our calorie intake is by monitoring our weight. Adjustments can then be made to our calorie intake to maintain a healthy bodyweight.