- Subcutaneous fat is uniformly distributed in human body and it plays role in warm and cold adaptation. Various variations related to age, sex, population and ethnic groups are found with respect to body fat which is both due to genetics and environment.
- Role in warm and cold adaptation (1) warm- thin layer of subcutaneous fat (2) cold- higher fat level
• Measurement : special caliper (pinching)
• Variations
(1) Age related changes
- (a) Fetus at 34 weeks – Body fat begins to be laid and increases until birth and attains peak by 9 months of age.
- (b) 9 months to 8 yrs- negative velocity-due to action of Growth Hormone. Sex differences-negative velocity is less in female.At age 8 years female /girl tends
- to have more fat than boy
- (c) 8 years to puberty-increase in fat level in both sexes. At puberty / adolescences -male /boy-reduction in trunk and limb fat but girl-increase in trunk faterotic figure.
(2) Definite pattern of subcutaneous fat deposition in body : High saturation of subcutaneous fat in subscapular region, abdominal region (trunk), arms, thigh and buttock, calf and limbs
(3) Dual control of fat deposition /level
(a) No. of fat cells: genetic control
(b) Amount of fat filled in fat cells : environmental control
(4) Genetic control– study of fat distribution in Bushman and Hottentots which shows that significant amount of fat is deposited in thighs and buttocks but other population living in same environment does not show same pattern.
(5) Role of adiposity in blood pressure variation
(a) Pattern of distribution of fat is more important than total amount of fat in BP.
(b) Upper body fat more closely related to hyper tension than lower body fat
(c) Trunk fat more related to coronary heart disease than fat in extremities
(d) Overweight in adulthood causes hypertension, cardiovascular disease, renal failure etc.
(e) Nirmala et al -Andhra Pradesh study- centripetal fat or deep intra-abdominal fat is more active cause of high blood pressure.