Psychology of Eating and Drinking

Introduction

• The course is about the psychology of eating and drinking.
• Instructor contact information is provided.
• Course materials, including the course handbook, are available on iLearn.
• Tutorials will start the following week.
• Students should stay in the same tutorial group, if possible.

Why study feeding and drinking?

• Eating and drinking are essential for survival.
• Evolutionary forces have shaped our physiology and anatomy related to ingestion.
• Examples include color vision, liking for junk food, and tendencies to gain weight.
• Understanding the physiology of these behaviors is crucial for various reasons including development, nutrition, and health.
• Malnutrition and obesity, both global concerns, are discussed.

Why study feeding and drinking? (Alcohol & Drugs)

• Alcohol dependence and related deaths are a significant global issue.
• Biological, psychological, societal, and economic factors contribute to alcohol dependence.
• Processed foods may also contribute to dependencies.
• Examples of research cited: the preference of mice to prefer sugar over cocaine.

Why study feeding and drinking? (Eating disorders)

• Eating disorders, especially anorexia, are extremely severe and potentially fatal.
• Factors influencing eating disorders include biological, psychological, social, and economic aspects.
• Eating disorders are increasingly common in the Western world.

Answers?

• This section provides questions about the topics related to eating, drinking behaviour and the associated biological & social issues involved.
• Examples include questions about our perception of food, satiety, societal, and economic factors in these issues.

Course structure

• The course will start by examining the basics of ingestion.
• Key topics include energy metabolism, food types, the digestive system, water balance, and feeding strategies.

Then...

• The coming weeks will focus on:
• The perception of food and drink
• The nature of thirst.
• Food-related drugs and preferences
• Food taboos.
• Psychobiology of food intake.
• The food system from production to consumption.
• Obesity, starvation, eating disorders, body image, etc.

Things you need to know

• Lectures and videos (Echo360).
• Readings (lecture notes, Logue chapter[s] & tutorial papers.)
• Additional supplementary readings (in the course handbook).
• Assessment information is included in the course handbook.
• End-of-semester exam: multiple choice (50%).
• Personal research project (report): 50%.

Energy metabolism

• Food provides chemical energy, which the body converts to mechanical energy (muscles), electrical energy (nerves), and heat.
• Key food constituents for energy include carbohydrates, proteins, and fats.

Main metabolic pathways

• Chemical reactions in the body to generate or produce energy.
• Pathways for digesting protein, sugars and starches and fat.
• How the body stores energy and how it converts it into various forms of energy.

Measuring the 'energy' in food

• Kilocalories (kcal) are the standard unit.
• Convert to kilojoules (kJ) by multiplying kcal value by 4.184.
• Bomb calorimeter measures energy content per gram of food (fats, carbohydrates, and proteins).

What are the bodies energy needs?

• Basal metabolic rate (BMR) is the minimum amount of energy expenditure needed to maintain basic body functions (around 70% of daily energy use).
• Daily energy requirements vary based on factors like gender, weight, daily activity, and physiological or health factors.
• Examples are provided, showing calorie expenditure based on activity (Shopping, Walking, Running).

Calculating energy needs

• Most energy calculators/tables take BMR and activity level into account to determine daily needs.
• Activity levels are categorised (very light, light, moderate, and heavy).

Consequences

• Average Australian daily caloric intake is significantly higher than the recommended levels for maintaining a healthy lifestyle.
• Low caloric intake, during specific circumstances such as for examples in concentration camps, have led to starvation and death.

Carbohydrates, fats, and proteins

• Types and functions of carbohydrates (simple and complex).
• Types and functions of fats (saturated, monounsaturated, and polyunsaturated).
• Types and functions of proteins.
• This includes micronutrients and minerals.

Micronutrients - Vitamins

• Deficiencies relatively rare in Western nations but it is still significant in many countries around the world.
• Types (Fat-soluble and water-soluble).
• Roles and importance of particular vitamins.

Micronutrients - Minerals

• Common elements of the mineral group.
• Roles and importance of particular elements.
• Common deficiencies of these elements.

Human digestive system

• Function to extract nutrients from food.
• Structure (main and accessory organs)
• Processes of (mechanical, chemical and enzyme) digestion.

Water balance

• Water is essential for life.
• Processes of water loss through the human body.
• Processes of maintaining water levels.

Conclusion

• Overview of the course topics covered.
• Implications of these issues for human health, across the different populations and countries around the world.

Feeding strategies in animals

• Adaptations to different food sources.
• Strategies of various species.

Introduction

• Animal kingdom example of feeding behaviours
• Methods of exploitation of food sources across a variety of species.

Adaptive radiation

• The diversity of feeding strategies based in environments and adaptation
• How food needs are met across varieties of species.

The need for food

• Importance of food for energy for survival and reproduction
• Issues of food poverty and hunger.

What constrains feeding strategies?

• Factors affecting the nature and processes of food acquisition and consumption, by species.
• Factors such as animal size, genes, environment, behaviour and time constraints.

Classifying feeding strategies in animals

• Classification of animals based on their feeding behaviours, including herbivores, carnivores, parasites, omnivores and filter feeders.

Feeding in herbivores

• General characteristics of herbivores, including diet, gut adaptations, and specific feeding approaches.

Grazing

• Grazing as a feeding strategy, focusing on characteristics (e.g., source of food, palatability), and adaptations of grazing animals.
• The characteristics of grass.
• Special adaptations of grazing animals.

Herbivore guts for grazing

• The digestive systems and adaptations of herbivores for processing plant material such as grazing strategy, including cellulose digestion.
• Examples: sheep and rabbits

Flowers, fruits, seeds

• Specialists on these food types, like pollen feeding insects, birds, bats, and monkeys Specific adaptations.

Hummingbirds

• Description of hummingbird feeding behaviour, including examples of high rates of metabolism and feeding cycles.

Other herbivores

• A variety of species of plant-eating species and behaviours.
• This includes the importance of dung beetles in maintaining ecosystems.

Carnivores - conclusions

• General characteristics of carnivores (diet, meal frequency).
• Important concepts like hunger and satiety, contrasted with herbivores.
• Features/adaptions in various animals.

Carnivore guts

• Digestive systems and adaptations of carnivores for processing animal material.
• Examples of different carnivorous species and their adaptations are illustrated.

Types of predator

• Various types of predator feeding strategies: (browsing, hunters, stalkers, carrion).

Filter feeders

• Filter feeding as a feeding strategy.
• Description of filter feeding in baleen whales as an example of filter feeders.

Stalking, Leopard seals

• Specific adaptations and behaviour of predatory animals, like leopard seals.

Stealth - Vampire bat

• Description and adaptations of predatory animals, like vampire bats.

Carrion - the vulture

• Carrion feeders (e.g., vultures).
• Adaptations for finding and consuming dead animals.

Feeding in parasites

• Definitions
• Examples of parasitism
• Adaptations and the transmission cycle of parasite.
• Examples: tapeworms.

Omnivores - conclusion

• Omnivores as a feeding strategy.
• Adaptive advantages/disadvantages
• Comparisons to other feeding strategies

Advantages

• Dietary variety and flexibility of omnivores.
• Ability to adapt to changing food resources.

Disadvantages

• The risk of consuming toxic or unhealthy food items.
• Potential complications in digesting and obtaining energy from diverse food sources.
• Potential problems like poisoning.

Consequences

• The issues of selecting the right food, brain development, dietary habits and behaviours relating to food avoidance, and cultural influences.

Conclusions

• Summary of the diversity of feeding strategies, including specific adaptations for each group, to obtain energy.
• Questions related to sensory perception, behaviour, and how animals adapt their eating to varying circumstances.