Adipose Tissue

EDDIE SMITH LEAH WAGNER

LEAH SANDERS JONATHAN GRIMWOOD

FWS

What is adipose tissue?

Groups of adipocytes (lipid filled cells) that are loosely held together by collagen fibers and connective tissue cells.

Functions Source of energy Heat insulation Mechanical cushioning

What is adipose tissue?

Formed from pre-adipocytes Fat cells that have not yet been filled with lipids Already present in adipose tissues Can grow through adult life

One capillary per adipocyte for improved metabolism Fat is primarily an energy source

Storing energy as another source would be inefficient and limit mobility “Buffer” when energy expenditure is greater than energy intake

http://www.promocell.com/products/human-primary-cells/preadipocytes/

Composition of Adipose Tissue

Two Types White fat cells – most common form; used for energy,

insulation, and cushioning Brown fat cells – metabolically less active; primary

function is to generate body heat; can be activated with cold exposure

Unilocular vs. multilocularUni – single, larger lipid droplet Multi – many smaller droplets

www.sportsci.org

Composition of Adipose Tissue

60-85% Lipids 90-99% Triglycerides

Fatty Acids: myristic, palmitic, palmitoleic, stearic, oleic, linoleic

Others: FFA, diglycerides, cholesterol, phospholipids, cholesterol ester, monoglycerides (change based on diet)

5-30% Water 2-3% Protein

http://www.sportsci.org/encyc/adipose/adipose.html#distrib

How much resides in average adult?

Normal weight adults can have between 15-30% of adipose tissue

Current average is 28-40% body fat, due to recent obesity epidemic.

Even those with normal BMI had high fat % Lower BMI/weighing less does not always mean healthier

http://onlinelibrary.wiley.com/doi/10.1038/oby.2010.103/epdf

Mean Percentage Body Fat, by Age Group and Sex --- National Health and Nutrition Examination Survey (NHANES), United States, 1999--2004

How much resides in average adult?

Mean Percentage Body Fat, by Age Group and Sex --- National Health and Nutrition Examination Survey (NHANES), United States, 1999--2004

Ranges Based on AgeMale

16-19 yo average - 22.9%

60-79 yo average - 30.9%

Female 8-11 yo average - 32.0%

60-79 yo average - 42.4%

How average percentages differ?

American Council on Exercise

How much resides in average adult?

Essential levels of fat are necessary for insulation, protection, and energy purposes

Body uses fat for energy when at rest Lack of sufficient fat stores will prevent the body from

efficiently providing energy to the cells

Where can adipose tissue be found?

Subcutaneous – directly under the deepest layer of skin; insulation

Visceral – near organs; directly related to CVD & Hypertension

www.westlakedermatology.com

Distribution Men – Android/”Apple”

Upper body Waist Abdomen

Women – Gynoid/”Pear” Lower body Hips Thighs Buttocks

Note: Android/”Apple” storage sites are considered to be more dangerous to health because of fat location in relation to important organs.

www.sportsci.org

Determining factors of distribution

Genetics Family history is a great predictor of fat distribution patterns

Gender Male – Upper body (“Apple”)

Female – Lower body (“Pear”)

Age An increase in upper body/visceral fat has been observed in older

women.

“Yo-yo dieting” May increase upper body fat distribution

http://www.sportsci.org/encyc/adipose/adipose.html

Am J Clin Nutr. 1997 Jul;66(1):111-5