GCSE AQA Biology 1 Diet and Exercise

1. Diet must provide energy you need (not more)
2. Food Groups
   1. Carbohydrates

      Nota:

      • To release energy
   2. Fats

      Nota:

      • To keep warm and release energy
   3. Protein

      Nota:

      • For growth, cell repair and cell replacement
   4. Fibre

      Nota:

      • To keep everything moving smoothly through digestive system
   5. Vitamins and Mineral Ions

      Nota:

      • To keep your skin, bones, blood and everything else generally healthy
   6. Water

Nota:

• Speed at which chemical reactions happen in the body

1. Affected by...
   1. Gender
   2. Amount of exercise
   3. Genetics
   4. Muscle to Fat ratio
   5. Size - more cells

1. Malnutrition

   Nota:

   • Having too much or too little of one or more food groups (having an unbalanced diet)
2. Eating too much...
   1. Obesity

      Nota:

      • Caused by excess carbs or fat in diet (bad diet), overeating or lack of exercise
      1. Common in developed countries
      2. 20% or more over max. recommended body mass
      3. Health Problems

         Nota:

         • * Arthritis * Type 2 Diabetes * High Blood Pressure * Heart Disease * Some Cancers
         1. More sat. fat increases cholesterol
         2. Too much salt causes high blood pressure/heart problems
3. Eating too little
   1. Particularly in developing countries
   2. Health Problems

      Nota:

      • * Slow growth (in children) * Fatigue * Poor resistance to infection * Irregular periods (in women)
      1. Deficiency Diseases

         Nota:

         • Caused by lack of vits and mins... * Vitamin C - Scurvy * Protein - Wasting of body tissue * Vitamin D - Rickets * Calcium - Weak bones and teeth * Iron - Anaemia * Vitamin A - Poor night vision

1. More exercise usually = healthier
2. Increases amount of energy used and decreases amount stored as fat
3. Builds muscle - boosts metabolic rate
4. Can still be malnourised

1. May inherit underactive thyroid gland

   Nota:

   • Can lower metabolic rate and cause obesity
2. High cholesterol

   Nota:

   • Cholesterol is a fatty substance needed for good heath. Some inherited factors can increase its levels.

1. Large survey can tell if diet is effective
2. To lose weight...
   1. ...take in less energy than you use

      Nota:

      • Eat less fat or carbs and do more exercise