Diet and Exercise

Biology 1 Part 1- Diet and Exercise Seven components of a healthy diet Carbohydrates Proteins Fats Minerals Vitamins Fibre Water Metabolism- all the chemical reactions that occur in cellsMetabolic rate- how quickly all the reactions that occur in cells happenWhat happens when you exercise? Muscles contract to move limbs They need energy to contract Muscle cells respire more, to release energy To provide energy the body needs more food Exercise increases the amount of energy expended by the body Obesity Obesity (having a BMI of 30 or above) can lead to type 2 diabetes, arthritis, breast cancer and an increased risk of strokes, heart disease and heart attacks. UnderwightBeing underwight (having a BMI of less than 18) can lead to an ineffective immune system, deficiency diseases such as rickets due to a lack of a component in a diet, and women can have irregular periods. Malnourishment Some people do not eat a balanced diet. They eat the wrong amount of types of foods. A person is malnourished if their diet is not balanced. Muscle to fat proportions in the body Fat cells- fat cells store fat. They are inactive and have a low rate of respiration to ensure they don't use stored fat.Muscle cells- they are active. Muscle cells need energy from respiration to contract. Their rate of respiration is high. More muscle than fat= high metabolic rateMales generally have more muscle and less fat in their bodies than women. This is largely determined by genes. Inherited Factors and Metabolic Rate Tall people have a higher metabolic rate as they lose more heat from their body surface Contrary to popular belief overweight people have a higher metabolism than slimmer people as their bodies are larger and need more energy to work An underactive thyroid gland leads to a lower metabolic rate