A healthy diet is one that helps maintain or improve health. It is important for the prevention of many chronic health risks such as: obesity, heart disease, diabetes, and cancer. A healthy diet involves consuming appropriate amounts of all nutrients, and an adequate amount of water. Nutrients can be obtained from many different foods, so there are a wide variety of diets that may be considered healthy diets.
Macronutrients
Protein
Protein is needed primarily for repair and growth of the human body. Protein consists of amino acids, some of which can be made from other proteins, some of which are essential amino acids. A healthy diet requires sufficient quantities of all essential amino acids. Increased requirements of amino acids occur for repair of muscles after strength training and a small amount is used for growth. Amino acid requirements are largely dependent on muscle mass; men generally require larger dietary protein intake for this reason.
Some strictly epidemiological evidence shows an increased mortality with high red meat intake.
Fat
Fat is used in the body for forming cell membranes, oxidised for energy, and can be stored by the body for later use if food intake is inadequate. Fats come in three main types: saturated fat, monounsaturated fat and polyunsaturated fat. Trans fat, a kind of unsaturated fat found in large quantities in foods such as margarine, is now known to be harmful.
Carbohydrate
Carbohydrates are chemicals that can be broken down in the body to simple sugars like glucose, fructose. Glucose is primarily used by the body in muscles but is the primary energy source used by the brain. If an excess of carbohydrate is consumed then it is stored with a large quantity of water as glycogen in the skeletal muscles and the liver. Fructose cannot be used by the skeletal muscles, but is converted into glucose by the liver. However if large quantities of fructose are consumed, the conversion produces triglycerides which are thought not to be healthy. One major source of fructose is sucrose (table sugar), fruits also contain substantial quantities, and so should not be taken in excess.
Energy
The human body creates energy from chemical reactions (mainly oxidation) of food. Due to conservation of energy if more energy is absorbed from food, then weight gain occurs (in the form of glycogen and its associated water) and fat. Some variation in weight can also occur due to hydration levels.
Different components of the diet provide different number of net calories, roughly speaking proteins provide about 4.5 kCal, carbohydrates about 5 kCal and fats, 9.5 kCal per gram.
Research has showed that the idea of thin people having a 'fast metabolism' is false; human beings burn energy at quite predictable rates, and gain or loss of weight is mostly to do with calorie intake versus the bodies' basal metabolism (with people with more lean bodyweight burning more calories) as well as (usually to a lesser degree) activity levels; with any long-term excess being stored as fat.
Energy is also used for growth and repair.
Source : wikipedia.org
Macronutrients
Protein
Protein is needed primarily for repair and growth of the human body. Protein consists of amino acids, some of which can be made from other proteins, some of which are essential amino acids. A healthy diet requires sufficient quantities of all essential amino acids. Increased requirements of amino acids occur for repair of muscles after strength training and a small amount is used for growth. Amino acid requirements are largely dependent on muscle mass; men generally require larger dietary protein intake for this reason.
Some strictly epidemiological evidence shows an increased mortality with high red meat intake.
Fat
Fat is used in the body for forming cell membranes, oxidised for energy, and can be stored by the body for later use if food intake is inadequate. Fats come in three main types: saturated fat, monounsaturated fat and polyunsaturated fat. Trans fat, a kind of unsaturated fat found in large quantities in foods such as margarine, is now known to be harmful.
Carbohydrate
Carbohydrates are chemicals that can be broken down in the body to simple sugars like glucose, fructose. Glucose is primarily used by the body in muscles but is the primary energy source used by the brain. If an excess of carbohydrate is consumed then it is stored with a large quantity of water as glycogen in the skeletal muscles and the liver. Fructose cannot be used by the skeletal muscles, but is converted into glucose by the liver. However if large quantities of fructose are consumed, the conversion produces triglycerides which are thought not to be healthy. One major source of fructose is sucrose (table sugar), fruits also contain substantial quantities, and so should not be taken in excess.
Energy
The human body creates energy from chemical reactions (mainly oxidation) of food. Due to conservation of energy if more energy is absorbed from food, then weight gain occurs (in the form of glycogen and its associated water) and fat. Some variation in weight can also occur due to hydration levels.
Different components of the diet provide different number of net calories, roughly speaking proteins provide about 4.5 kCal, carbohydrates about 5 kCal and fats, 9.5 kCal per gram.
Research has showed that the idea of thin people having a 'fast metabolism' is false; human beings burn energy at quite predictable rates, and gain or loss of weight is mostly to do with calorie intake versus the bodies' basal metabolism (with people with more lean bodyweight burning more calories) as well as (usually to a lesser degree) activity levels; with any long-term excess being stored as fat.
Energy is also used for growth and repair.
Source : wikipedia.org
Tidak ada komentar:
Posting Komentar