Keys to Weight Loss

Calories are units of energy in food which are used by the body following digestion. Weight loss and weight gain are dependent upon the number of calories consumed, the number of calories burned or utilized and the degree of balance or imbalance between the two. If calorie intake exceeds calorie burning weight gain occurs. If calorie burning exceeds the calorie consumption, weight loss occurs. Calories provide the energy for growth and development, various cell functions including digestion, many of the chemical reactions that occur in the tissues of the body and physical activity associated with muscle use, but when calorie intake exceeds calorie utilization the extra calories are stored in the body as fat.  

Approximately 90% of dry weight of the average diet and 100% of the calories are derived from three main food types. Those food types are carbohydrates, proteins and fats. The calorie value for each food type is specified in terms of the number of calories per gram. There are 4 calories in a gram of carbohydrates, 4 calories in a gram of protein and 9 calories in a gram of fat. Our bodies use more than just the energy from food but also the smallest chemical particles of the food, known as molecules, as building blocks for body parts and enzymes which are proteins that speed up chemical reactions in the body. For this reason the total daily calorie intake should be balanced between carbohydrates, fats and protein.  

Carbohydrates include simple sugars and more complex chemical particles known as starches and fibers which are present in foods such as potatoes, bread, pasta and grains such as rye. According to most authorities, carbohydrates should comprise between 50 and 55% of total daily calories. 

The primary sources of protein in the diet are meat, beans, eggs, nuts, soybean, soybean products and milk products. Between 10% and 15% of the total daily calorie intake should be in the form of protein. 

Because of the higher calorie content in fat it is considerably harder to lose weight if fat is not restricted as a source of total daily calories. The amount of fat in the diet should be limited not only if weight loss is the goal but also because of the link between fat intake and diseases of the heart and blood vessels. Authorities generally recommend that less than 30% of the daily calorie intake should be in the form of fat. 

In the fasting state, our bodies harvest energy stored in our bodies in the form of proteins, carbohydrates and fat by a series of chemical reactions known as metabolism which is vital for sustaining life. The form of metabolism known as catabolism, involves the breakdown of carbohydrates, protein and fats and to provide energy for cellular activities such as brain function, heart function, lung function and physical activity. The other form of metabolism which is the building process and which includes processes such as part of growth and development, healing, etc., is known as anabolism.  

It is the catabolic form of metabolism which is involved in weight loss in the one toward which attention should be directed in any type of weight loss program.  When our digestive tracts are inactive and we are not physically active, our bodies utilize a set amount of energy to perform the many chemical and biological functions necessary for maintaining life. That set energy requirement is known as the basal metabolic rate (BMR), which is expressed as calories per day.  BMR decreases with age and is generally higher in males than in females. Additionally, BMR decreases with obesity and increases with increased muscle mass.  Certain disease states can also affect the BMR. For example, an under-functioning thyroid gland (hypothyroidism) decreases the BMR.   

Because muscle cells and other tissue cells require more energy during physical activity, the body breaks down the sources of stored energy (particularly fat) during exercise and weight loss occurs if the amount of energy utilized is not replaced or exceeded by the dietary intake of energy in the form of calories after or preceding the exercise or other forms of physical activity. The increased metabolism associated with physical activity explains why exercises so important in weight loss programs. 

There basically two forms of exercise, aerobic and anaerobic.  Aerobic exercise is generally moderate intensity exercise that is sustained for extended periods. It involves increased breathing and utilization of oxygen by the body, whereas anaerobic exercising is not sustained for extended periods of time and is of high intensity. Anaerobic exercising also does not involve the increased utilization of oxygen during metabolism and is not associated with as increased a rate of metabolism as is aerobic exercising.  Brisk walking, jogging and playing tennis are examples of aerobic exercise. Weightlifting is the most common form of anaerobic exercise. 

Because the metabolic rate during aerobic exercising is significantly greater than during anaerobic exercising, aerobic exercising is much more effective in achieving immediate weight loss, when supplemented with a weight loss diet. Although immediate weight loss is not usually seen with anaerobic exercising, scientific observations suggest that anaerobic exercising lowers the BMR, which in the long run can be beneficial in achieving weight loss since it is the balance between calorie intake and calorie burning that determined weight loss or weight gain.  

Because of the relationship between calorie intake, calorie burning and weight loss, the most successful weight loss programs include a combination of a well-balanced, healthy weight-loss diet and safe exercising. The use of a weight calculator might be extremely helpful in helping you coordinate a weight loss diet and exercise in your weight-loss program.

by Victor E. Battles, M.D. - January 24, 2010

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Source: http://www.proactivehealthoutlet.com