Biological explanation to obesity

• what is obesity?

  condition of being chroncially overweight with excessive body fat

  Measured by BMI
• What is the BMI?

  Body Mass Index

  compares height to weight in order to determine if you are overweight
• What is the genetic explanation of obesity?

  FTO gene- regulates enzymes associated with obesity

  Individuals with variant are at higher risk of obesity

  MC4R gene- produces a protein works with leptin to communicate to hypothalamus to stop eating- Variant= no protein is produced
• What is the neural explanation of obesity?

  damage to the ventromedial hypothalamus leads to excessive eating
• What is research support for FTO gene

  Frayling

  gene of 38,000 europeans

  Found= carriers of one risk variant weigh 1kg more than average

  Carriers of two risk variant weigh 3 kg more than average
• What is the research support for MC4R gene?

  GIANT (organisation not person)

  comapred studies (meta analysis)

  Found= 14 genetic variations in 13 genes in 1 in 5000
• What is a weakness of the genetic explanation for obesity?

  risk gene suggest number of people should be lower than reality

  (more obese people than number of people with risk)
• What is research support for the neural explanation?

  Hetherington and Ranson

  damage to the ventromedial hypothalamus in rats caused hyperphagia

  Wang

  obese people have lower dopamine recpetors than normal
• what is a weakness of the neural explanation for obesity ?

  fails to consider role of media

  social learning factors
• what are the strengths and weakness for the biological explanation for obesity

  Genetic

  +ve= frayling - FTO gene

  GIANT- MC4R gene

  -ve= risk gene suggest the number of people should be lower than the reality

  Neural

  +ve= Hetherington and Ranson- VMH damaged in rats

  Wang= dopamine receptors are lower

  -ve= fails to consider the role of media