Health 101: Understanding Body Composition, Obesity & Body Fat

1. Body Composition -
   1. In the domain of physical fitness, body composition is used to describe the percentages of fat, bone, water, and muscle in human bodies.
   2. Body Weight is the measurement of weight without items located on the person.
   3. Muscular tissue takes up less space in our body than fat tissue, and conventionally, more leanness means better body composition.
      
   4. Two people of same sex and body weight may look completely different from each other because they have a different body composition.
   5. Men tend to carry more water than women. as women carry more "essential fat" than men. Additionally, men inherently have a relatively larger amount of skeletal muscle. For these reasons, men contain about 60 percent water while women have 55 percent water.
   6. Fat contains only 10% water. Bones contain 22% water. Muscles contain glycogen, the storage form of glucose; which is 75 percent water, thus muscles are also 75% water; same as the water composition in our brains. 
   7. Body Volume Measurement helps in determining a person's health, by providing the required dimension for calculating the distribution of body weight.
      
      
      
      
2. Obesity -
1. Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health.
   
2. Obesity is most commonly caused by a combination of excessive food intake, lack of physical activity, and genetic susceptibility.
   
3. Obesity is more common in women than men.
   
4. On average, obese people have a greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass.
   
5. Obesity is mostly preventable through a combination of social changes and personal choices.
   
   
3. Body Fat -
   1. Body Fat Percentage (BFP) of a human or other living being is the total mass of fat divided by total body mass.
   2. Body fat is actually a loose connective tissue known as the "adipose tissue".
   3. Irrespective of the location from which they are obtained, the fat cells in humans are composed almost entirely of pure triglycerides with an average density of about 0.9 kilograms per liter.
   4. Body fat is a  major endocrine organ, as it produces hormones such as leptin, estrogen, resistin, and the cytokine TNFα.
   5. Epidemiologically, the percentage of body fat in an individual varies according to sex and age.
   6. The body fat percentage is a measure of fitness level since it is the only body measurement which directly calculates a person's relative body composition without regard to height or weight.
      
      
      
4. Total Body fat includes:
   1. Essential body fat -
      
      1. Essential body fat is necessary to maintain life and reproductive functions.
      2. The percentage of essential body fat for women is greater than that of men, due to the demands of childbearing and other hormonal functions.
      3. Essential fat is the level below which physical and physiological health would be negatively affected.
      4. The percentage of essential fat is 3–5% in men, and 8–12% in women (referenced through NASM).
      5. The minimum recommended "total body fat percentage" exceeds the essential fat percentage value.
         
   2. Storage body fat -
      Storage body fat consists of fat accumulation in adipose tissue, part of which protects internal organs in the chest and abdomen.
      
      
      
5. Types of Body Fat:
   1. Subcutaneous
      1. under the skin
      2. may stay the same with age
   2. Visceral (intra-abdominal fat)
      1. located inside the peritoneal cavity, packed in between internal organs and torso.
      2. may increase as you age
      3. Visceral fat is composed of several adipose depots:A.) mesenteric, B.) epididymal white adipose tissue (EWAT) and C.) perirenal fat.
   3. Intramuscular
      
      1. interspersed in skeletal muscle
      2. may increase as you age
         
         
         
6.   Types of Adipose Tissue
   1. White adipose tissue (WAT) -
      primarily stores energy.
   2. Brown adipose tissue (BAT) -
      primarily generates body heat in cold conditions.
      
      
      
7. Body Fat Percentage Chart - Males
   
   
   BMI vs Bodyfat levels - Males
   
   
   Body Fat Percentage Examples - Males
   
   
8. Body Fat Percentage Chart - Females
   
   
   BMI vs Bodyfat levels - Females
   
   
   Body Fat Percentage Examples - Females
   
   
9. Body Fat Percentage Chart - Advanced
   Find your age on the left-hand column, and then see the corresponding ideal body fat percentage to in the blue colored "Lean" area on the right.



Notes -

1. You may have noticed as your age increases, your acceptable body fat within these ranges increases as well, it's because these charts are based on "statistical assumptions".
2. Older individuals tend to have a lower body density for the same skinfold measurements, which is assumed to indicate a higher body fat percentage.
3. Older, athletic individuals, however, might not fit this assumption because their body density may be underestimated.

References -
https://en.wikipedia.org/wiki/Obesity
https://en.wikipedia.org/wiki/Adipose_tissue
https://en.wikipedia.org/wiki/Body_fat_percentage
https://en.wikipedia.org/wiki/Body_composition
https://en.wikipedia.org/wiki/Abdominal_obesity
https://en.wikipedia.org/wiki/Human_body_weight
http://extaping.com/articles-amp-videos/knowledge-base/sports-training/article/82.html