Combating obesity

Question 1

Introduce how biological psychology can be used to combat obesity

Answer 1

• In today’s society there is an abundance of food, with obesity becomign a global epidemic as prevalence reaches 25% of adults in the UK (NHS Digital, 2018).
• Despite popular beliefs that overeating and obesity are underpinned by choice, lack of control, or maladaptive eating, the research does not support this simplistic view (Garrett, 2015).
• Control of eating involves a complex biological system of neural circuitry and hormones suggested to be impared amongst obese patients.
• Therefore, this essay discusses the biology of ingestive behaviour, its impairments in obesity, and how this information can pave newer treatment options for obesity.

Question 2

Discuss the failures of direct administration of endogenous hormones

Answer 2

• Knowledge of these biological mechanisms of appetite provide means of treating the obesity crisis.
• However, this requires more complicated solutions as research has shown the failure of direct administration of endogenous hormones.
• For example, PPY trials cause severe nausea (De Silva & Bloom, 2012), and leptin is largely ineffective as 90% of obese patients are leptin resistant rather than leptin deficient.
• Furthermore, data suggests obese patients have low relative serum ghrelin compared to learn counterparts (Carlson, 2010).

Question 3

List the current anti-obesity drugs

Answer 3

• There are currently five approved anti-obsity drugs in the USA (Daneschvar et al., 2016).
  
  • ​Orlistat prevents absorption of intestinal fats
  • Lorcaserin is a sertonin agonist
  • Phetermine/topiramate
  • Naltrexone (unknown mechanism)
  • Liraglutide (GLP-1 agonist)
• GLP-1 is an incretion (gut homrone increasing insulin secretion) normally stimulated by ingestion of foods rich in fats and carbohydrates.

Question 4

Discuss newer therapeutic options for treating obesity

Answer 4

• Kim et al. (2012) outline a variety of therapeutic approaches to regulating food intake.
• Many of the mentioned drugs in development lose effectiveness upon Phase 2 research, possess too shoft half-lives, or are withdrawn due to safety concerns.
• Promising therapies include:
  
  • ​Oxyntomodulin (OXM)
  • Ghrelin vaccines, antagonists, and blockers
  • Pancreatic polypeptide
  • Amylin/Leptin co-therapy

Question 5

Describe the mechanisms of newer anti-obesity drugs in development

Answer 5

• OXM’s mechanism in unknown; yet, intravenous infusions are observed to suppress appetite and feeding, and increase physical activity in humans, with few adverse effects (Kim et al., 2012).
• Pancreatic polypeptide is homologous to PYY.
• Obese patients display lower levels of PP.
• It is shown to decrease appeitite and limit weight gain in obese mice models (Kim et al., 2012).
• Amylin induces weight loss amongst type 1 and 2 diabetes.
• Obese rat models demonstrate the role of leptin in potentiating this effect, which has transferred to human models and is advancing into Phase 3 trials (Kim et al., 2012).

Question 6

Conclude the use of biological psychology to combat obesity

Answer 6

• In conclusion, obesity is a global epidemic that has biological elements beyond widely believed lack of control and overeating.
• These biological mechanisms consist of neural circuitry: first-order neurones in the arcuate nucleus; plus secon-order neurones in the hypothalamus.
• These neurones stimulate or inhibit orexinergic peptide secretion that determine the initiation of food-seeking behaviours.
• The arcuate nuculeus recieves several hormones that stimulat or inhibite these neurones.
• Sadly, direct administration of endogenous hormones has failed in clinical trails.
• Yet, this area is actively growing, as the biological mechanisms provide direction for new drug development indirectly acting upon these signals.