OVERWEIGHT AND OBESITY Flashcards
how do you calculate BMI?
weight (Kg)/ height (M squared)
BMI accounts for variations in height, but what factors does it not account for?
sex, age, pregnancy, athletes, or muscle mass
which guides give us a rough index of how much of each food groups we should eat?
the eatwell guide and the food pyramid
whats wrong with our diet in the UK?
we dont eat enough fruit and veg or oily fish. we eat too much free sugar, saturated fat, red and processed meat.
what percentage of adults are classified as overweight or obese?
63%
is the prevalence of obesity linked to deprivation?
yes they are directly correlated
is there a ‘best diet’?
The best diet is to eat a sensible number of calories, eat a variety of foods, eat plenty of fruits and vegetables and to eat plenty of food rich in starch and fibre.
or the Mediterranean diet
what is the Mediterranean diet?
High fruit, veg, whole grain, olive oil
High micronutrient, fibre, unsaturated fat
what are the impacts of being overweight or obese?
high bp, low HDL, high LDL, high risk of diabetes, cardiovascular disease, premature mortality rate, high cancer rates, high fasting free fatty acids, high fasting glucose and high plasma TGs
what are plasma TGs?
plasma triglycerides
describe the difference between men and women body shapes?
men- apple-shaped with abdominal obesity
women- pear-shaped with gynoid obesity
is there a worse place to put on fat?
why?
yes the abdomen
the fat accumulated here tends to be more visceral fat which secretes more adipokines and fatty acids. Visceral adipose fat can also drain into the hepatic portal system which directly affects the liver and can be rapidly transported around the body.
what width of the waist should you stay below in men and women?
men- 94cm
women- 80cm
(very high risk is men above 102cm and women above 88cm)
what diseases is abdominal fat associated with?
higher risks of heart disease, insulin resistance and diabetes, higher mortality
how much does risk of mortality increase with central obesity and a BMI 30+?
men x2
women increase by 40%
how do you keep a healthy weight?
an energy balance where energy intake=energy output
what happens when you’re in a negative energy balance?
we get a loss of energy store, body weight, carbohydrates, fats and proteins
what happens when you’re in a positive energy balance?
gain in energy store, body weight, carbohydrates, fats and proteins
what is leptin?
a hormone released from adipose tissue which acts on the hypothalamus to derease food intake by reducing hunger. it inhibits ghrelin being released from gastric cells
what gene encodes leptin?
the ob gene
what is ghrelin?
a hormone released from cells in the GI tract which increases hunger
which group of people have higher ghrelin?
those with anorexia nervosa, particularly the purging type
describe insulins action after a meal?
insulin secretion increases to stimulate glucose uptake by GLUT4, glycogen synthesis and fatty acid synthesis.
why is insulin an anorexigenic signal?
it reduces appetite
whats the problem with constantly worrying about dieting?
stress produces cortisol which can ause weakened immune system, anxiety, depression, headaches, nerve problems, digestive issues, high blood sugar, high blood pressure and heart disease.
why was being obese an evolutionary survival advantage?
The ability to store energy when food is plentiful as food supplies were irregular
why is a crash diet not efficient?
you lose glycogen which has water molecules conjugated to each glcose so the weight you lose is mostly water
what should the food industry do to reduce obesity prevalence?
advertise variety and have clarity in packeging labels
what should the government do to reduce obesity prevalence?``
regulate the food industry
what should the clinicians do to reduce obesity prevalence?
They should be non-judgemental, supportive, subscribe exercise and reinforcing messages about making conscious choices
what should the individual do to reduce obesity prevalence?
make conscious choices, avoid dieting and exercise more reguarly
how can clinicians measure someones food intake?
food diaries, surveys, nutritionist interview, photographing food, weigh food, doubly-labelled water or calorimetry
how can we boost energy expenditure?
by maintaining lean muscle mass
whats the problem with trying to measure a patients food intake?
many under-report
