Background+2

=Weight Management=

Simple statements first:

Energy intake > energy expenditure = body will store excess energy supplies as fat Energy intake < energy expenditure = body will use stored fat as an energy source and fat loss will occur Energy intake = energy expenditure = body weight will be maintained.

The optimal rate of fat loss should be a slow and sustained rate over a period of time. This allows the body greater time to adapt.

When losing weight by reducing calories the following things are happening in your body: 1. The body loses fluids which are essential for efficient functioning, resulting in tiredness and demotivation 2. The body will assume that it is experiencing famine like symptoms and will: a) Adapt to function with less energy b) Hold on to greater concentrations of essential fat, and lose non-essential muscle c) Make the muscle burn fewer fat calories even at rest to conserve fat stores d) Lower the Basal Metabolic Rate

Great website for understanding the BMR calculation here and how many calories you should eat. The key to weight loss is not the reduction in the amount of food that you eat. You will actually cause yourself more harm in the long run with a slowing down of the metabolic rate and making it easier for the body to store fat in the long term.
 * BASAL METABOLIC RATE** is the rate at which calories are burned. This is also the rate at which your body uses calories for maintenance activities. (calculate your BMR here)

One of the keys of successful fat loss is to maintain a high BMR. People with a high BMR are usually thin.

Factors that will raise BMR: 1) Eating frequent small meals, as this requires energy. 2) Exercise, which increases the need for energy 3) Environment; hot and cold temperatures require the body to work harder 4) Height - tall and thin people have higher BMI 5) Muscle mass - more muscle, more energy needed

Lowering BMR 1) Fasting/Starvation 2) Age, as you go over 20, BMR reduces 3) Excessive Sleep

Estimating Basal metabolic rates: Men = 1 calorie/kg of body weight/hour Women = 0.9/kg of body weight/hour e.g. an 84kg man would calculate his BMR as 1x84x24hrs=2016 basal calorie needs

Remember that this calculation is **NOT EXACT** but merely a guide, something similar to the BMI calculation discussed in the previous unit.

You would then have to factor in the activity factor, as a multiplier so: BMRxActivity = calorific expenditure The activity factor depends on the type of activity that you are doing. Refer to the tables given in class.


 * __Coronary Heart Disease__**

Please review the following powerpoint with background to coronary heart disease:



How can exercise help with preventing heart disease/Stroke (blockage to the brain) 1) Low intensity exercise can help by preventing the storage of significant portions of fat due to them being used. 2) High intensity exercise can help to flush out the arteries. It also helps to refuel glycogen stores in the muscles.


 * __Obesity__**

Obesity is defined as when body fat levels are 25 percent greater than the gender norm.

There are many things which contribute to obesity. 1) Excessive intake of calories over the required daily amount 2) Poor diet, high in saturated fat and LDL cholesterol 3) Lack of physical activity 4) Genetic predisposition.

See this series for information regarding your project: []


 * __Osteoporosis__**

Osteoporosis is a disease which affects the bones. The bone becomes weaker overtime, eventually fracturing. Bones that break as a result of osteoporosis can cause permanaent disability or death.

Bone is living tissue which responds to exercise. The strength and density of bone will increase the more it is used.

Osteoporosis is seen a lot in elderly people with limited physical activity. You can improve bone density through activities which place weight on the bone, such as jogging and running, or any activity that requires your legs to bear your weight. Weightlifting can help with bone density as it puts the muscle under stress and helps the development of both muscle and bone.

More information: []

__**Food Grouping and Nutrition**__ Please refer to the guided reading for more information in this section

Hunger is a **physiological** factor. Our stomach is designed to digest food every 4-5 hours. Larger meals will 'stretch' the stomach, whereas starvation will shrink the size of the stomach. We should eat smaller meals more frequently rather than large meals infrequently.

Appetite is a learned or **psychological** response and it is learned. Think of the different things which can make you hungry or which can make you lose your hunger.

Vitamins and minerals essential to life: [] []

Water, heat and oxygen are also required to sustain life. Water is essential for the body to operate. The body is made up from 2/3rds water. Oxygen is required to produce energy for the physiological processes. The correct heat is required for the physiological processes to take place. When we overheat, we give away water into the environment. We also give away water when we breathe and through our urine.


 * __Hydration__**

Hydration refers to a state when the body has sufficient oxygen. Dehydration is when the body is operating without sufficient amounts of water.

Water: 1) Helps to digest food in the intestines and in the creation of saliva 2) In blood it transports nutrients around the body 3) Lubrication of joints 4) Urine carries waste out of the body 5) Sweat removes body heat that would have been trapped during exercise

Signs of dehydration: 1) Thirst 2) Headache and/or fatigue. Cramps (Heat cramps) 3) Sickness, chills, increased heart rate, no sweat. This is Heat exhaustion. 4) Cells will begin to donate water to important organs. Gradually organs will shut down. 5) Dehydration can be fatal when 9-12 percent of your body weight is lost because of water loss.

You need to drink water regularly. 1ml of water for each calore you burn, so 3-4l per day. This is based on the amount of exercise that you do! Water lost through sweating also loses electrolytes. You need these electrolytes to regulate the water content. If you just drink water you will continue to dehydrate or drown your organs. Fresh fruit is a good source of electrolytes. Avoid caffinated drinks at these are diuretics (lose water). Loss of electrolytes can interfere with the transport systems in the body, and upset fluid regulation and affect thermoregulation (keeping the body at an acceptable temperature).


 * __The Food Pyramid__**

Remember that the food pyramid does not apply equally to all people. There would be a food pyramid for under 11s, and one for older people, as they have specific dietary requirements. The food pyramid for males and females are also slightly different.

[]


 * __Cholesterol__**

Remember that cholersterol comes in two forms: LDL and HDL. Cholesterol is transported around the body attached to a protein. The density of LDL or HDL lipoproteins depends on the relationship between the fat and the protein in quantity. Having large quantities of LDL in your blood stream will lead to deposits forming in the arteries, including the coronary arteries where is contributes to narrowing. Exercise will either use the fats as a direct source if the intensity is sufficiently low or alternatively fat deposits will be used after exercise both to replenish glycogen and phosphagen stores. It is also used to fuel the recovery process and post exercise elevated metabolic rate. Exercise will also ensure that arteries are flushed regularly, helping to prevent plaque build up.


 * __Dietary Requirements for Exercise__**

1) If the activity requires a lot of energy then an increase in carbohydrates will be needed 2) If the muscles are worked excessively then a high protein diet will be needed to aid growth and repair 3) If the activity is long in duration, then extra B vitamins will be neeeded to help respiration and the production of blood cells 4) Extra liquids will be needed in hot or cold climates to replenish water and electrolyte stores.


 * __Ageing__**

A number of prominent athletes are competing 'past their primes'. However there are a number of physiological changes associated with ageing:

Muscular Strength: 1) Loss of skeletal muscle mass decreases performance. This has an effect on resting metabolic rate, regulation of blood glucose, temperature regulation, and protection of internal muscle structures 2) Loss of **type 2 muscle fibres** 3) Reduction in muscle size 4) Increase in fat within the muscle

Some biological and sociological reasons for muscle degeneration: 1) Less active as we age 2) Nerves degenerate 3) Increase in collagen fibres which reduces muscle flexibility

Cardiovascular and cardiorespiratory endurance 1) Significant decline in aerobic activity after 30 2) Maximal oxygen uptake down by 15 percent per decade after 30 3) Gradual reduction in cardiac output

Reasons: 1) Decline in heart rate 2) Decreased ventricular contractile performance 3) Decline in total blood volume

Lung: 1) Alveoli increase in size with age, but decrease in their ability to transfer 2) Gradual loss of elasticity within the lungs 3) Reduction in the volume of gas exchange

Our **Resting metabolic Rate** reduces as we age due to a more sedantary lifestyle.

Flexibility: Wear and tear on your connective tissue plus increased collagen content and the addition of scar tissue from injuries. There also tends to be a reduction in bone density with females beyond their menopausal age.