Option C.3

Question 1

C.3.1 Describe how obesity is determined (along with limitations on calculations and effects on childhood obesity)

Answer 1

Obesity is by definition an excess of body fat, but in reality it is determined using indirect measurements of body, for example body fat index BMI and waist circumference

BMI a measurements of body fat, calculated by dividing weight in kilograms by height in meters squared - > indirect assessment of body fat percentage (inits kg/m^2)

A BMI less than 18.5= under
A BMI between 18.5 and 25= normal
A BMI between 25-30= overweight (Obese I)
A BMI 30-40 = obese (Obese II)
A BMI 40+ = morbid obese (Obese III)

Values can be often misleading - bodybuilders weightlifters, large muscles

Childhood obesity-> associated with social stigmatization and bullying (This raises an ethical issue around the routine)

Question 2

More accurate assessments of body fat %s: (and their limitations!)

Answer 2

-> sophisticated imaging techniques, including dual energy x-ray absorptiometry (DXA), magnetic resonance techniques (MRI), and computed tomography (CT)

-> can be costly
->time consuming, DXA/CT low doses of radiation

Question 3

C.3.2 Outline the major health consequences of obesity

Answer 3

->Cardiovascular disease and hypertension
->type 2 diabetes
->osteoarthritis
->respiratory problems
->some forms of cancer

Question 4

C.3.3 Discuss the concept of energy balance

Answer 4

if energy intake is less than expenditure there will be a weight loss / vice versa to energy intake is greater than expenditure;

if the intake = expenditure, then weigh will remain stable;

energy expenditure = internal heat produced/BMR + external work;

energy intake = total number of calories taken in daily.

Question 5

C.3.4 Outline how chemical signals arising from the gut and from the adipose tissue affect appetite regulation

Answer 5

hormones are produced by the stomach and small intestine ✔

hormone «leptin» secreted by fat cells/adipose tissue ✔

hormones enter the blood stream ✔

hormones/leptin/ghrelinact on the appetite control centre ✔

leptin inhibits eating/causes satiety✔

ghrelin increases the desire to eat ✔

obese ppl deficient in this = always hungry)
-> exercise helps to reduce both subcutaneous fat ( underneath the skin and the fat within the abdomen)