obesity Flashcards
nutritional diseases
They are any nutrient-related disease and condition that causes illness in humans
-It includes deficienxies or excesses in diet, eating disorders and chronic diseases such as cardiovascular, hypertension and diabetes
-it is also developmental abnormalities prevented by diet, hereditary metabolic disorders that respond to diets and interaction of foods with drugs, allergies and potentila hazards in the food supply
extreme examples of malnutrition in SA
-Poverty and undernourishment results in deficiency of iron, iodine and vitamin A
-Other hand there is poor diet, high fat, refined carbohydrates and sodium that promotes metabolic syndromes of obesity, high blood pressure and insulin resistance
Obesity
abnormal or excessive fat accumulation
BMI of overweight
obese= >30kg/m2
overweight: 25-29.9kg/m2
World problem of obesity
1 billion obese people
Increased by 27% in adults and 47% in children from 1980-2013
obesity related diseases
-type 2 diabetes
-non-alcoholic fatty liver disease
-non-alcoholic steatohepatitis
-cardiovascular disease
-cancer
-Increased susceptibility to infectious diseases and poorer outcomes, eg SARS-cov-2
Obesity imbalance
Imbalance between caloric intake and energy expenditure
-Caloric intake in excess is stored as fats in adipose tissue as well as glycogen in organs
Adipose tissue
Consists of white adipose tissue (WAT) and a small percentage of Brown adipose tissue (BAT)
WAT function
-It is an endocrine gland that produces adipokines (hormones) such as leptin and adiponectin which affect glucose and fat metabolism
-It also secretes cytokines that increase/decrease inflation such as TNFalpha, Il1beta, il10
WAT location
WAT is distributed all over the body
-Abdomen
-Greates deposists are in omentum, bowl and perenial areas
-Subcutaneous fat is located in buttocks, thighs and abdomen
-different locations have different metabolic and endocrine characteristics
BAT
Brown adipose tissue
-It contains many mitochondria and utilises fat to generate heat through uncoupling of electron transport chain by UCP-1
-Process is called adaptive thermogenesis
-BAT represents 1-2% of total body fat and is NB in thermogenesis in babies and maintaining energy homeostasis
Pro inflammatory cytokine
IL1beta
Anti-inflammatory cytokine
IL10
WAT sensitivity to hormones
WAT in the breasts and buttokcs is highly sensitive to eostrogens while WAT in the upperback and neck is sensitive to glucocorticoids
-Visceral WAT has an adipokine secretion profile related to type 2 diabetes and inflammation
Obesity- associated disease drivers
-A key driver is the formation of adipose tissue of systemic and persistent (chronic) low grade inflammation
-It is mediated by macrophages and other immune cells that migrate into fatty tissue and produce pro-inflammatory molecules
-Obesity can cause a phenotypic switch of WAT characterised by appearance of inflammed, dysfunctional adipocytes along with infiltration of immune cells
-Immune cells and inflamed adipocytes secrete both locally and systemically, pro-inflammatory cytokine which disrupt normal funcyion of WAT and remote organs