What is obesity classed as?
What was it classes as previously?
Before: regarded as a condition caused by a lack of self-control.
Now: as a complex illness
What 3 things leads to obesity?
Tasty calorie dense food
Sedentary Lifestyle (exercise is more compulsory than what you need to do to survive).
More of the population has too much food avaiable to them
High fat, suar and carbohydrate food.
How is it encoded in us from our anciesters?
Previously those that survived were the ones the could store energy best for starvation periods.
Will obesity kill you?
It only makes you more at risk of other diseases
What diseases does obesity increase the risk for?
6 of them
Dyslipidemia (increase amount of lipid in the blood)
Type 2 Diabetes
How to calculate Body Mass Index?
BMI= Weight / (height)2
Classifications of obesity when thinking of BMI?
Up to BMI of 25: thin or normal-acceptable.
BMI of 25-29.9: Overweight
BMI of 30-39.9: Obese
BMI of >40: Morbidly obese
Trend in US Obesity since 1985?
Obesity levels have increased throughout US.
Southern side and moves outwards.
Early data increase was due to more states reporting.
Percentage of males and females obese in England?
36% of males.
28% of females.
This obesity trend in the US? Is it only the US?
Similar trends reported in many other western countries.
All them following US.
What kind of epidemic is obesity?
Is this increase only confined to adults?
No there was found to be an prevalence of overweight and obesity in school age children.
What is the human cost of obesity?
Higher risk of early death
Shortens life by 9 years.
Lot more sick days.
Economic cost of obesity?
An increase in the number of sick days therefore losing money in the economic output.
Increase in the cost of NHS treatment: 9% of total healthcare budget it on overwight/obesity conditions.
Obesity is now classed as 2 things?
What will happen now it is classed as a disease and a disability?
Disease: health insurance will icnrease.
Disability: effect the workplace
Cause of obesity?
Higher levels of inactivity
Increased cosumption of high-fat foods
Definition of obesity as a disorder?
Not a single disorder
A heterogeneous group of conditions with multiple causes.
Major factors influencing obesity?
Genetics: suscepibility genes. Increase risk of developing disease (not essential for disease expression).
Environment: latent tendencies to develop obesity. Westernisation diet.
Define energy balance disturbance?
Difference between energy intake and expenditure.
What has happened in the last decade in the expression of type 2 diabetes mellitus?
>30% in America.
Increase in pre-diabetes.
90-95% of cases are classified as overweight/obese.
Consequences of Obesity?
Obesity virtually guarantees bad health.
Osteoarthritis (loss of cartilage at the joints)
NAFLD (fatty liver disease)
Gout (acute arthritis causing pain & swelling at joints)
Fatty liver disease
Eat so much that the fat stores cannot cope and the excess fat is stored in the liver.
How is obesity a disease of the brain?
Increased body fat alters brain function.
Your brain views the extra weight (fat) as normal and dieting as threat to body survival.
Long-term obesity induces brain re-programming.
CNS influences energy balance and body weight by 3 ways?
Behaviour: feeding and physical activity.
ANS activity: regulates energy expenditure.
Neuroendocrine system: secretion of hormones.
What organ is for integration energy intake?
What neural center is responsible for energy uptake?
How is the enery balance controlled?
Controlled by feedback loops.
Act to maintain constancy of total body energy stores.
How do these energy balance signals act?
Signals are produced in response to body nutritional status.
Sensed in the hypothalamus.
Act to modulate food intake and energy expenditure.
What are the 2 Short term processes?
Regulate meal intitation, termination and
Satiation: increase during meal to limit meal size.
Satiety: The state produced by having had a specific
need,such as hunger or thirst, fulfilled.
Name the 5 satiation signals produced from the GI tract?
Glucagon-like peptide 1
What is Ghrelin?
A hunger signal.
Produced by oxyntic cells in stomach.
Levels increase before meals and decrease after meals.
Stimulates food intake and decrease fat utilization.
Possess BAT (brown adipose tissue): adult humans.
At the neck, clavicle and spinal cord.
White adipose tissue can be induced brown.
Generates heat without shivering.
Increase energy expenditure
Long-term appetite controllers?
Glutamate, GABA and opioids increase food intake when injected into hypothalamic centers
Monoamines act to suppress food intake
Define adiposity signals?
produced in peripheral tissues
Act on hypothalamic neurones
Made and released from fat cells.
Made and released from pancreatic cells.
Leptin and insulin
Levels increase in blood as more fat is stored.
inform brain to alter energy balance- malfunctions in obese state.
Crucial elements in physiological pathways for energy balance control.
Mutations leads to obese state.
Ob gene is responsible for the production of what hormone?
Mutations in Ob gene because of obesity?
Effects level of Leptin
Body thinks its in starvation mode
What happens to the leptin expression in diabetes?
db gene is mutated.
Effecting the leptin receptor (Ob-R)
db gene is responsible for?
leptin receptor (Ob-R) chacteristics?
Single TM receptor
Similar to class 1 cytokine receptors.
Long cytoplasmic domain
Highly expressed in the hypothalamus
Responsible for intracellular singla transduction.
Leptin characteristics and the receptor?
Circulates in proportion to body adiposity.
letin receptor highly expressed in ARC hypothalamic neurones.
Leptin inhibits food uptake and decrease body weight
Insulin characteritics and its receptor?
Circulates in proportion to body adiposity.
Enter the brain
levels of insulin receptors are high in ARC hypothalamic neurones.
Insulin inhibits food intake and decrease body weight.