Many of us believe that our lives consist of a beginning, middle, and, finally, an end. However, many of us may not recognize that there are several other degrees of life that we must pass through. The human life cycle starts at conception and continues until death. As we move through the different stages of life, our nutritional requirements continually change and, as we mature, our bodies require more of some nutrients and less of others. The nutritional needs of an infant differ from those of an adult and the nutrients required by a pregnant or lactating woman differ from those required by a 60 year old man. Infancy, adolescence, pregnancy, lactation, menopause, and aging place unique nutritional demands on the body. To maintain a healthy life, a balanced diet of carbohydrates, proteins, fats and oils, minerals, vitamins, and water are required. But, how much of each of these nutrients are needed by the human body? The Institute of Medicine has published recommendations for Dietary Reference Intakes (DRIs)¹ that are age specific for the various stages of life. However, the DRIs are not applicable for individuals who suffer from chronic illness or for those who are at high risk for illness due to age, genetics, or lifestyle choices such as smoking, alcohol intake, drug use, and strenuous exercise or activity. Health care providers and clinicians must determine nutritional requirements in such cases based on a patient's health history and available information. Nutrients
Surprisingly, our bodies requires the same nutrients throughout our lifespan. However, the quantity of nutrients and calories required by the human body will vary and change depending on age and gender, as well as health. Pregnancy and lactation also effect the nutrients and calories necessary to maintain a healthy lifestyle. The human body must have nutrients to function. The nutrients essential for the human body are proteins, carbohydrates, fats and oils, minerals, vitamins, and water. They are provided by eating a balanced diet of whole grains, vegetables, fruits, beans, and proteins such as meat and fish. Proteins Proteins consist of amino acids, small units necessary for growth and tissue repair. Except for water, and possibly fat, proteins are the body's most plentiful substance. Animal foods rich in protein consist of milk, eggs, poultry, fish, and meat. Excellent plant sources of protein are cereals, breads, beans, nuts, and peas. Carbohydrates The main source of the body's energy is provided by carbohydrates consisting of starches and sugars. Carbohydrates account for approximately fifty percent of the calorie intake for Americans and as much as four fifths of the calories in the diets of Africans and Asians. Foods rich in carbohydrates, such as potatoes, corn, wheat, and rice, are also a main source of protein for most of the world's populations. Sugars provide energy (calories) but have no nutritional value and are called empty calorie food.
Fats and Oils
Fats and oils, referred to as liquid fats, are concentrated sources of energy. The human body requires fats in the diet for good health. They provide certain vitamins as well as cushioning for vital organs. They make up a portion of all cells in the body and help maintain body temperature. Since foods containing fat remain in the stomach longer, they help delay hunger pangs.
Minerals are neither vegetable nor animal. They are inorganic....