Start with the fundamentals.

Nutrition is the study of how food and drink provide energy and materials the body uses to function, grow, repair itself and maintain health.

A calorie is a unit of energy. Food supplies energy that the body uses for basic functions, movement, growth, repair and temperature control.

Protein is a nutrient made from amino acids. The body uses it to build and repair tissues and to make enzymes, hormones and many other important compounds.

Carbohydrates are a major source of energy and include sugars, starches and fibre. Their nutritional value depends heavily on the food that contains them.

Dietary fat provides energy, helps absorb certain vitamins and supplies fatty acids the body needs. Different types of fat have different effects.

Dietary fibre is the part of plant foods that is not fully digested. It supports bowel function and can contribute to fullness, blood-sugar regulation and heart health.

Vitamins are organic compounds needed in relatively small amounts for normal body functions. They do not provide calories, but they help the body use energy and perform essential processes.

Minerals are inorganic nutrients the body needs for functions such as bone structure, fluid balance, oxygen transport, nerve signalling and muscle contraction.

Water is essential for circulation, temperature regulation, digestion, waste removal and nearly every body system. Fluid needs vary considerably.

Digestion breaks food into smaller components that can be absorbed and used. The mouth, stomach, intestines, liver, pancreas and gallbladder all contribute.

A balanced diet supplies enough energy and nutrients without routinely providing too much of components that can be harmful in excess. It can take many cultural and practical forms.

A simple meal-building guide is to make about half the plate vegetables and fruit, one quarter whole-grain foods and one quarter protein foods, with water as the default drink.