Nutrition and Biochemistry(Lecture No. 6)

OBESITY (MOST COMMON PROBLEM OF OVER NUTRITION)

Accumulation of excess body fats: obesity is the physical state in which the amount of stored fat is excessive. It results when energy intake exceeds energy expenditure.Anyone who is more than 20%, above the standard weight of the people of same, age, sex, and race is generally considered to be overweight. It is still not clear, whether obesity is a disease or symptom which manifests a group of diseases like Gout, D.M., HTN and endocrine disorders.

IMPORTANCE OF OBESITY:Obese person are more prone to certain disease CVS DISORDERS: HTN, atherosclerosis, angina, varicose veins.LIVER DISEASE: fatty liver, cholecystitis, cholelithiasis.(FFFF)METABOLIC DISEASE: Gout (hyper uricemia), DM-IIGYNECOLOGICAL DISORDERS: Amenorrhea, oligomenorrhea, Endometrial Carcinoma.

ASSESSMENT OF OBESITY:Amount of fat is difficult to measure directly, so indirect measure is the body mass index (BMI): shown to correlate amount of body fat in most individuals.BODY MASS INDEX: Basically BMI gives relative weight adjusted for height, is calculated both for men and women.BMI = Weight in kg/m2 (Height in meter)2

= Weight in LBs/ (Height in inches) 2 x 7.3BMI healthy Range = 19.5 ……………. 24.9 (Normal)BMI with = 25 ………………..29.9 (Overweight)BMI 30 or =..…………………. 30 (Obese)

Types TYPES OF OBESITY:

OBESITY IS DIVIDED INTO TWO TYPES:EXOGENOUS: Over feeding or over eating with less physical activity. Many people over eat than calories requirement (more eat either happily or under tension).ENDOGENOUS: there may be one or more endogenous factors e.g.Endocrinal, metabolic, hypothalamic.

PATHOLOGICALLY TYPES OF OBESITY:HYPERPLASTIC: Hyperplastic is lifelong,

characterized by ↑in no. of adipose cells and↑ size of adipose cells.

Fats distribution is peripheral and central but when individual is exposed to weight reduction adipose cells shrink in size but ↑in number of cells persistently remains same.

HYPERTROPHIC: (Adults-on-set) Seen in adults after 20 years, it is characterized by hypertrophy of cells of adipose ↑ (size of cells) without ↑in no. of adipose cells i.e. ↑of cell only. Long term weight reduction response is fairly good

ANDROID (Apple shaped or upper body obesity): excess of fat is located in central abdomen waist to hip ratio is more than F 0.8: M 1.0

GYNOID (Pear shaped or lower body obesity): Excess of fat is distributed in lower extremities waist to hip ratio is less than F 0.8: M 1.0

Waist more than 40”in Males at risk CHD,, ,, ,, 35” in Females ,, ,, CHD

CAUSES OF OBESITY: Obesity is most commonly due to over eating

than required calories:I. GENETIC INFLUENCE: Obesity occurs more

frequently among members of certain familiesII. PHYSIOLOGICAL: over eating than

requirement, during pregnancy endocrine play role ↑in wt or obesity, post-menopausal in women, prolong use of oral contraception.

III. METABOLIC: DM-II hyperlipidemia IV. HYPOTHALMIC INJURIES: and lesions

causes people to eat more & more and become obese.

5. ENDOCRINAL DISORDER: it is due to hormonal imbalance e.g. hypo-thyroidism, Cushing syndrome, hypo-parathysidism.

6. AGE: Moderate accumulation of adipose tissue may occur at any age but more common at middle age.

7. SEX: adult women are more prone to obesity as compared to men. 15% body wt. is twice that of young men. Women in menopause, become obese and more frequent to become obese in pregnancy and prolong use of oral contraceptive use.

METABOLIC CHANGES DURING OBESITY:

CHANGES IN FAT METABOLISM: Insulin resistance in adipose tissue causes ↑ “hormonal sensitive lipase” which causes↑ FFA, ↑TAGS, ↑Cholesterol in Plasma.

Serum TAGS level: ↑Tags level due to hyperinsulinism in obese patient.

Serum Cholesterol level: ↑Hyper cholesterolemia due to ↑cholesterol productions in obesity results.

Mobilization of FFA: ↑Insulin Resistance in adipose causes l↑evel of Level of hormonal sensitive lipase which result ↑FFA level, ↑TAG level, ↑ Cholesterol level.

CHANGES IN CARBOHYDRATES: Obesity is associated with ↑Hyper-insulinemia (β cell of islets of Langer-Hans stimulates to produce↑ insulin) more aggravate promoting i)↑Lipo-genesis ii) inhibit lipo-lysis

CHANGE IN ACID- BASE STATUS:Massive obesity associated ē Hypoventilation leading to CO2 Retention, ↑acidosis ↓in pH leading to obesity Hypoventilation syndrome (Pickwickian syndrome). ENERGY METABOLISM BMR: obese persons BMR, appears to normal. His surface area large, total O2 consumptions is ↑than 25%, than normal. Use of O2 is greater, burns as fuel than normal, yet continuous to store fat.

CLINICAL FEATURES OF OBESITY: mostly are asymptomatic when obesity is marked, exertional Dispnea, depression, Tiredness, easy fateagueability, Alveolerhyporventilation ē CO2 retention.

Sign: exertional dyspnea, intertigo, pinkstriae, on abdomen, thighs, white striated in fold below breast and inguinal regions, ē HTN, D.M, ankleoedema.

WEIGHT REDUCTION:The goals of wt. management in obese pts are first to induce negative energy balance – to reduce

body wt.PHYSICAL ACTIVITY:An↑in physical activity can create an energy deficit

and is an important component of wt loss treatment. Physical activity ↑in cardiorespiratory fitness ↓risk for C.V.S disease

CALORIC REDUCTION: Caloric intake should be less than caloric expenditure. ↓of body wt over 6 months often ↓BP ↓lipid level ↓D.M.

PHARMACOLOGICAL TREATMENT:Obese who have BMI more than 30 can be

treated by SIBUTRAMINE (appetite Suppressant): is

an appetite suppressant that inhibits the re-uptake of both serotonin and non-epi-nephrine.

ORLISTAT (Lipase inhibitor): is a lipase (Pancrectic, Gastric) inhibitors that inhibits Gastric and pancreaticlipesas which breakdown dietry fat into smaller molecules. So no absorption of fat, no obesity

LEPTIN:Leptin is produced proportional to adipose mass in edipocytes which inform the brain to regulate the amount of fat through

1 apetite control by decreasing appetite

2 by increasing energy expenditure. secretion enhanced during well fed state.

Leptin secretion is suppressed by depletion of fat stores, during starvation,and leptin secretion enhanced during wellfed state.

SURGICAL TREATMENT: GastroplastyGestro-pyloroplastyLiposuction: It is latest technique having merits and

de-merits.ANTI-OBESITY VACCINES: SCRIPS VACCINE:

Ghrelin hormone that regulate the energy balance and ↓about 20 – 30% wt of mice, yet has to try in humans.

CYTOS ANTI OBESITY VACCINE: (SWISS)It prevents the Ghrelin’s uptake by the brain