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PWP Episode 16- Health Psychology: Biological Explanations for Obesity

Hello everyone, I hope that you had a great weekend.

Today’s episode of The Psychology World Podcast is on Health Psychology. This is an area of psychology that draws influence and knowledge from biological psychology, cognitive psychology and social psychology.

More specifically, we’ll be looking more at the Health Psychology of the biological explanations for obesity.

The show notes from today’s episode are taken from my Health Psychology Book:

Biology of addiction:

Personally, this is an interesting one because before I read this one section of health psychology about two years ago. I never really thought of fats as drugs, but you should be able to see the link after this section.

Addiction leading to obesity is done in the following way:

· When you eat fats and sugary foods your brain secretes dopamine as a reward for you. This makes you feel amazing.

· Then you continue to eat this type of food so you can continue to get this rush. Similar to drugs.

· Then over time your brain and body builds up a tolerance to these foods and stops producing dopamine.

· Therefore, you eat more and more of these foods to get the same rush.

· In the end, as a result of you having to eat so much in order to get this rush. You built up fat quickly as you’re eating possibly thousands of more calories than you’re burning off. Leading to obesity.

Genetic factors:

Haworth et al (2008)

· Using over 2000 twins aged 7 and over 3500 aged 10, the researchers conducted a twin study to test the inheritability of BMI and obesity.

· The parents of the twins filled in a questionnaire with their children’s measures and weight so their BMI could be calculated.

· Based on their BMI the children were categorized into normal weight, overweight and obese.

· Then the BMIs were correlated between identical and fraternal twins.

· Results showed that for both types of twins’ genes played a major role in the development of obesity. Their role was about 60%-74%.

· In conclusion, BMI and obesity are largely determined by genetics. That’s the study in its simplest form.

Critical thinking:

This study has high construct validity as the method used to measure BMI and obesity is very effective. As questionnaires were a quick and simple way to get the information on the children and other factors. Instead of an interview as this can be very time consuming and expensive. Therefore, this effective method allows the researchers to measure what they want so they can draw reliable conclusions from their data.

However, as this is a twin study, it is open to population fallacy; where your sample group doesn’t actually represent your target population.; because most of the population aren’t twins. Thus, it could turn out in reality that the percentage of inheritance is much higher or lower in non-twins.


The hormone Leptin is involved in the energy consumption of people.

Fat and sugary food can lead to addiction as when you eat it the neurotransmitter dopamine gets released.

Haworth et al (2008) demonstrated that obesity can be inherited.

I hope that you joined today’s podcast episode and if you want to learn more about Health Psychology then please consider checking out my Health Psychology book. Available on Amazon, Kobo, Apple Books and many more bookstores in Print, Large Print, Ebook and Audiobook.

Please consider signing up for my newsletter to get your free Psychology book and learn more about psychology.

Have a great week everyone!

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