§-Topic

Topic 1: Principles of Human Nutrition

8 dot points, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.

How do a person's nutritional needs change across the stages of life?

Explain how nutritional requirements change through the life cycle, including pregnancy, infancy, childhood, adolescence, adulthood and older age

Nutritional needs change across life: pregnancy and infancy demand extra nutrients for growth, adolescence raises energy and iron needs, and older age shifts requirements as activity and absorption change.

6 min read →

How does the community of microbes living in the gut influence human health?

Describe the gut microbiome and explain how diet shapes it and how it influences digestion, immunity and health

The gut microbiome is the community of trillions of microbes living in the large intestine. Fed by dietary fibre, it ferments food, makes some vitamins, trains the immune system and is linked to many aspects of health.

6 min read →

How do digestive enzymes chemically break large food molecules into absorbable units?

Explain the role of digestive enzymes in the chemical breakdown of carbohydrates, proteins and lipids, including the conditions that affect enzyme activity

Digestive enzymes are biological catalysts that break large food molecules into small absorbable units. Each enzyme is specific to one substrate and works best at the temperature and pH of its part of the gut.

6 min read →

How does the body use the energy in food, and what determines how much it needs?

Explain basal metabolic rate and total energy expenditure, and the factors that affect a person's daily energy requirements

Basal metabolic rate is the energy the body uses at complete rest. Together with physical activity and the energy used to digest food, it sets total energy expenditure and the kilojoules a person needs each day.

6 min read →

What happens to health when the body cannot properly digest or absorb particular nutrients?

Explain the causes and consequences of malabsorption syndromes and food intolerances, including lactose intolerance and coeliac disease

Malabsorption is the failure to absorb nutrients properly, often from missing enzymes or a damaged gut lining. Lactose intolerance and coeliac disease are common examples with distinct causes and dietary management.

6 min read →

Why does the body need vitamins, minerals and water even though they supply little or no energy?

Describe the functions, food sources and deficiency effects of key vitamins and minerals, and explain the role of water in the body

Vitamins and minerals are needed in small amounts but are vital for body processes, while water is the medium for almost every reaction. Deficiencies cause specific, often serious, disorders.

6 min read →

How do the macronutrients supply energy and building materials for the human body?

Describe the structure, food sources and functions of carbohydrates, proteins and lipids, and explain how each contributes to the body's energy balance

Carbohydrates, proteins and lipids are the three macronutrients. They provide energy and raw materials, with each gram of fat releasing roughly twice the kilojoules of carbohydrate or protein.

6 min read →

How does the digestive system break food down into nutrients the body can absorb and use?

Describe the structure and function of the digestive system and explain how macronutrients are digested and absorbed

The digestive system mechanically and chemically breaks food into small molecules that are absorbed in the small intestine. Specific enzymes act on carbohydrates, proteins and fats.

6 min read →