OBESITYZagada, Timothy M.

Obesity• Defined as abnormal or excessive fat

accumulation that presents a risk to health.• BMI of >30• Eating more in combination with reduced activity

levels has resulted in a tendency for the sustained deposition of fat.o The fundamental cause of obesity and overweight is an energy

imbalance between calories consumed and calories expended.

Obesity• an increased intake of

energy-dense foods • a decrease in physical

activity due to the o increasingly sedentary nature of

many forms of work, o changing modes of transportationo increasing urbanization

Obesity Facts from WHO

• Worldwide obesity has more than doubled since 1980.

• In 2008;o 1.5 billion adults, 20 and older,

were overweight.

• Overall, more than one in ten of the world’s adult population was obese.

Obesity Facts from WHO

• Nearly 43 million children under the age of five were overweight in 2010.

Obesity Facts from WHO

• Overweight and obesity are linked to more deaths worldwide than underweight.

• At least 2.8 million adults die each year as a result of being overweight or obese.

• Obesity is preventable.

How can we measure obesity?

Body Mass Index• A crude population measure of

obesity is the body mass index (BMI)

• Accounts for differences in body composition by defining the level of adiposity according to the relationship of weight to height.

• A person’s weight (in kilograms) divided by the square of his or her height (in metres).BMI = (weight in kg)/(height in meters)2

Body Mass Index• While it does not directly measure body

fat, it is more accurate at approximating degree of body fatness than weight alone.

• Allows comparisons both within and between populations.

Disadvantage of BMI• Very muscular individuals

often fall into the overweight category

o Muscle is denser than fat, it weighs more.

o Using BMI to assess their weight may result in overestimating their true level of body fat.

Other measurements• Measure midway between the

top of iliac crest and tip of lowest rib.

• Hip circumference should be measured around the widest portion of the buttocks

Measurement Male Female

Waist circumferenc

e

> 35 inches

> 31 inches

Waist to hip ratio

> 0.95 > 0.8

Adipose• Functions as the major storage site for

fat in the form of triglycerideso Our major fuel store is adipose triacylglycerol

(triglyceride)o if we eat more food than we require for our energy

needs, the excess fuel is stored (mainly in our adipose tissue), and we gain weight

• Energy ingested as fat beyond that needed for current energy demands is stored in adipose tissue.

• In addition, carbohydrate and protein consumed in the diet can be converted to fat

Adipose• The average 70-kg man

has approximately 15 kg stored triacylglycerol, which accounts for approximately 85% of his total stored calories.

Adipose• When triacylglycerols are

deposited in adipocytes, the cells initially show a modest increase in size

• When its maximal size is reached, it divides.

• Fat cells, once gained, are NEVER LOST.

• Thus, when an obese individual loses weight, the size of the fat cells is reduced, but the number of fat cells is not affected.

• The observation that fat cells are never lost emphasizes the importance of preventing obesity in the first place.

Anatomic differences in fat deposition

• Android - Excess fat located in the central abdominal area of the bodyo waist to hip ratio of more than

• 0.8 for women • 1.0 for men

• Gynoid - Fat distributed in the lower extremities around the hips or gluteal regiono waist to hip ratio of less than

• 0.8 for women • 1.0 for men

Android vs. Gynoid

• is associated with a greater risk for:o Hypertensiono insulin

resistanceo Diabeteso Dyslipidemiao coronary heart

disease

• is relatively benign healthwise, and is commonly found in females.

• Fat deposits are presumably energy reserves to support demands of pregnancy and lactation

1 cup Veg 16 kcal

1 cup Rice 200 kcal

1 cup Ice cream 267 kcal

1 cup Mayonnaise 720 kcal

CASE• Height: 5’8” (172.72cm)• Weight: 250lbs (113.6kg)• Physical Activity: Sedentary• BMI: 113.6/1.72= 39.3 (Obese

class II)

Patients Actual Caloric Intake

• CHO: 590g• CHON: 135g• Fat: 115g

X 4X 4X 9

= 2360 kcal= 540 kcal=1035 kcal3935 Kcal

Patients’ Ideal Body Weight and Caloric

Requirement• (IBW) Tannhausers

Methodo (172.72kg – 100kg) – 10%o 72.72 - 7.272o 65.5kg ~ 66kg

• Total Caloric Requiremento 66kg x 30= 1980 kcalo 2000 kcal

• Actual wt/ IBW113.6kg/66kg= 172%The patients’ wt is 72% above his IBW

• Corrected Body Weight (CBW)– [(Actual BW –IBW) x25%]+ IBW

– [(113.6–66) x 0.25]+ 66– [47.6 x 0.25]+ 66– 11.9 + 66– 77.9kg ~ 78kg

• Total Caloric Requirement– 78kg x 30= 2340 kcal– 2350 kcal

Caloric Distribution

• CHO- 55-70%• CHON- 10-15%• Fat- 20-30%

• CHO: 2350 x 60%= 1410 kcal• CHON: 2350 x 10%= 235 kcal• Fat: 2350 x 30%= 705 kcal

÷ 4÷ 4÷ 9

= 350g= 60g= 80g

Energy and Nutrient

Requirements

Actual• Calorie: 3935 Kcal• CHO: 590g• CHON: 135g• FAT: 115g

Required• Calorie : 2350 kcal• CHO: 350g• CHON: 60g• FAT: 80g