FOOD AND WEIGHT.

The human body is living engine, a labyrinth of activities, even at rest or during sleep the body requires energy for the brain to work, for the heart to beat, for the eyes to blink and for the digestive system to work. We all need energy to sweat, breathe, eat, laugh, and perform such daily activities like bathing, cooking, washing, driving, writing, walking. This energy is derived from the food we eat
Read more>>.

The calorie.

The amount of energy a food produces is measured in calorie or kilocalorie. A calorie is a standard measurement of heat energy. It is the amount of heat that it takes to raise the temperature of one kilogram of water by exactly one degree centigrade, that is, from 14.5*c to 15.5*c. while the biochemist, the dietician and the nutritionist calculate food energy in calorie or kilocalorie, the physicist prefers joules or kilojoules. However, both are interconvertible  as shown below:

1 Calorie= 1 Kilocalorie= 4.2 kilojoules.

The amount of energy that one gram of a Particular food substance can produce is known as the Calorie value of that food, for example.

1g of carbohydrates= 4 calories = 16.8 kilojoules.

1g of protein = 4 calories =16.8 kilojoules.

1g of fat = 9 calories = 37.8 kilojoules

Energy Need.

All the food substance we consume are eventually metabolized to provide energy and materials for new or replacement of old body substance, such as cells and tissues. The energy is utilized by the body in two distinct ways:

• Basal Metabolic Energy: This is the energy the body uses while at rest, that is, while the individual is lying down, in a warm environment, fully relaxed. This energy, which represents about 50-80%  of the total energy expenditure, is used to keep the body alive and functioning by the lungs (breathing and blood flow), kidney (excretion) and the various systems in the body such as the digestive, nervous, reproductive, and respiratory system and for the production of new or replacement of old body cells and tissues. The rate at which this energy is used up is known as the basal metabolic rate. The daily basal metabolic energy for the average man of 70 kg weight is 7030 KJ (1680 Kcal) while that for the average woman of 55 kg is 6019 KJ (1440 Kcal).
• Physical Activities: About 20-40% of the total energy available to the body is used to carry out various physical activities.

Energy Expenditure.

The amount of energy or calories an individual requires or expends depends on his height, weight, age, health, level of physical activities, etc. as shown below.

1.      Age:energy expenditure decreases with increase in age. This is because the process of energy generation and expenditure (anabolism and catabolism).

2.      Sex: Energy expenditure is higher in men than in woman. Men produce more heat compared to woman of the same age and size.

3.      Pregnancy: A woman expends more energy during pregnancy for the growth and development of the foetus.

4.      Breastfeeding: Breastfeeding mothers use more energy both physically and chemically than non-breastfeeding ones.

5.      Menstruation: A woman’s energy expenditure increases during menstruation.

6.      Cold: Exposure to cold increase energy expenditure in maintaining normal body temperature.

7.      Hyperthyroidism: Thyroid hormone is naturally involved in metabolism and growth. Excess production of it in hyperthyroidism results in the body generating excess energy

8.      Mental Activities: Increased mental activities especially during research or preparation for examinations, increase energy expenditure by increasing the brain demand for fuel (glucose).

9.      Physical Activities: All forms of physical activities involves the use of energy. The longer or more tedious the activity, the more energy is expended.

Positive Energy Balance.

 When a person eats too much food the produces more energy (calories) than he needs for his daily activities, the person will be in positive energy balance. The excess energy will be stored in the liver as glycogen. The has a limit to the amount of energy or glycogen it can store. Hence, once the liver has reached its limits, the excess energy is then stored as fat in the adipose tiassues.

If this person continues for a long time the consumption of food surplus energy, the body continues to store the excess energy as fat and the person continues to grow fatter, first becoming overweight and then obese.

Negative Energy Balance.

On the other hand, if a person eats too little food that is unable to provide the minimum energy required for his basic bodily functions, that is, his energy intake is less than his energy output; he will be in negative energy balance. The body will turn to itself  and use its own substance (essential protein fat  and glycogen in the flesh) to provide energy, thus making the person to lose weight. Starvation or weightb loss programme that compels the body to convert more than 40% of its original weight to energy for body activities will results death!

Maintenance Diet.

If the energy intake is equivalent to the energy output, the person’s weight will remain constant. Here, the person is said to engage in maintenance diet.

People can maintain a particular (usually desirable). Weight by engaging in a maintenance diet, that is, by regularly balancing energy intake by energy output through diet and exercise or physical activity..read more

it is a lifetime shedding pounds,click for more details

If you enjoyed this post and wish to be informed whenever a new post is published, then make sure you subscribe to my regular Email Updates. Subscribe Now!

Kindly Bookmark and Share it: