5/ Eating Behaviours - Biological explanations for obesity Flashcards
what are the two biological explanations for obesity?
- genetic explanation - thrifty gene
2. neural explanations - dopamine and serotonin
explain what is meant by the genetic explanation for obesity.
thrift gene has been passed down to increase survival - this gene allows people to make the most efficient use of their food intake and store the rest as fat.
what research is there to support the role of genes in obesity? 1
meta analysis of 8000 MZ twins and 10,000 DZ twins. MZ concordance rates were 60-80%.
what research is there to support the role of genes in obesity? 2
a study found there was a stronger association in weight categories between adopted child and biological parents rather then child and the adopted parents.
what weakness is there of the genetic explanation for obesity?
suggesting most people would have inherited the thrift gene if it aided survival and therefore most people would be obese.
what evidence suggest there must by social and cultural factors that affect obesity?
study found that half the worlds obese people lived in just 10 countries.
explain how dopamine may cause obesity.
dopamine stimulates brain areas that produce feelings of satisfaction and pleasure so obese people eat more to stimulate these feelings.
what research supports the idea of dopamine?
obese people have poorly functioning dorsal striatum leading to reduced dopamine signals in the brain.
explain how serotonin may cause obesity.
obesity is associated with low levels of obesity. usually serotonin signals is sent to the VMH when full and signals to stop eating. however if serotonin levels are low inaccurate signals are sent and leads to over-eating.
what research supports serotonin in obesity?
mice who were genetically engineered to have low levels of serotonin developed obesity.
