Comprehensive Study Notes on Diet and Growth: Balanced Diet

Definition of Diet: A diet is defined as the total food that an individual consumes each day. A diet should ideally provide some level of all the different kinds of nutrients and provide the body with the correct amount of energy.
Definition of a Balanced Diet: A balanced diet is specifically a diet that provides all the different kinds of nutrients required by the body in the correct proportions, alongside the right amount of energy for the individual's needs.

Sources of Energy: The cells in the body are constantly consuming energy. All of this energy is derived from the nutrients found in consumed food. * The primary nutrients providing energy are carbohydrates and fats. * Protein can also be used by cells to obtain energy.
Excessive Nutrient Intake: If an individual consumes more carbohydrates, fats, or proteins than the body's cells require for energy, the excess is not used. Instead, the body converts these extra nutrients into fat. This fat is stored primarily just below the skin.
Insufficient Nutrient Intake: If an individual does not consume enough nutrients to meet the energy demands of their cells, the body must find an alternative energy source. The cells will break down existing fat stores to provide the necessary energy, which results in weight loss.
Generic Energy Trends: * In general, men utilize more energy than women. * Individuals with active lifestyles use more energy compared to those who spend significant time sitting down (sedentary).

Factors Affecting Energy Usage: * Physical Activity: Those who participate in a lot of sport, or walk and run frequently, use more energy. Those who do not move around much use less energy. * Genetics: Some people have genes that cause their bodies to use up energy more quickly than others, even when performing the same activities. * Growth: Individuals who are growing fast (such as teenagers) need more energy to help their cells divide. * Body Size: Tall people generally use more energy to move their bodies around compared to smaller people.
Data on Mean Energy Needs: Based on a provided bar chart, the mean energy needs in Megajoules ( $MJ$ ) are as follows: * 8-year-old girl: Approximately $2.8\,MJ$ per day. * 8-year-old boy: Needs less energy than a teenage boy because he has a smaller body mass and fewer cells. Since it is the cells that use energy, fewer cells result in lower energy requirements. * Adult woman: On average, an adult woman needs less energy per day ( $MJ$ ) than an adult man. This is attributed to women generally having a lower body mass than men and potentially being less active.

Nature of Fibre: Fibre is not actually classified as a nutrient because it is not absorbed into the body, but it is an essential part of the diet.
Importance of Fibre: Fibre is vital because it helps keep food moving easily through the alimentary canal.
Sources of Fibre: Fibre is found in plant-based foods. Animal products do not contain fibre.
Dietary Fibre Content (Grams per $100\,g$ of food): * Coconut: $14\,g$ * Brown bread: $7\,g$ * Spinach: $6\,g$ * Beans: $5\,g$ * Peas: $5\,g$ * White bread: $4\,g$ * Corn: $4\,g$ * Yam: $4\,g$ * Bananas: $3\,g$ * Plantain: $3\,g$ * Potatoes: $3\,g$ * Rice: $3\,g$ * Apples: $2\,g$ * Fries (potato chips): $2\,g$ * Sweet potatoes: $2\,g$ * Chicken: $0\,g$ * Eggs: $0\,g$ * Fish: $0\,g$ * Mutton: $0\,g$
Fibre Calculation Example: A meal containing $200\,g$ of chicken, $200\,g$ of rice, and $100\,g$ of spinach: * Chicken: $0\,g$ fibre. * Rice: $2 \times 3\,g = 6\,g$ fibre. * Spinach: $1 \times 6\,g = 6\,g$ fibre. * Total fibre ( $6 + 6$ ) = $12\,g$ .

Sugar: Excessive sugar (a type of carbohydrate) can cause tooth decay and increases the risk of developing diabetes.
Fats and Carbohydrates: Consuming too much fat, oil, or carbohydrate leads to weight gain (obesity). This puts a physical strain on the body's organs, including the heart and joints.
Animal Fats: High consumption of fats specifically from animal sources can increase the risk of developing heart disease.

Starter Discussion: * Can you name the six nutrients that you need to eat? (Typically: carbohydrates, fats, proteins, vitamins, minerals, and water). * Which three nutrients can give you energy? Carbohydrates, fats, and proteins. * Which two groups of nutrients are needed in only small amounts? Vitamins and minerals.
Class Discussion: What is the difference between diet and balanced diet? (A diet is simply whatever is consumed; a balanced diet contains all nutrients in the correct amounts for health).
Different Diets Discussion: Do you think all of us need the same diet? (No, energy and nutrient needs vary based on age, gender, activity, and size).
Practice Exercise 7.2B: * Which two nutrients provide most of the energy for the cells in the body? Carbohydrate and fat. * A man regularly eats food containing more energy than he uses up each day. What will happen to his weight? His weight will increase. The excess nutrients will be turned into fat and stored in his body.
Exit Ticket Assessment: * I need protein for growth / energy. Answer: growth. * There is a lot of protein in sugar / fish. Answer: fish. * Starch and sugar / fat are carbohydrates. Answer: sugar. * I get energy from carbohydrate and calcium / fat. Answer: fat.