effects of diet

• insoluble and soluble fibres are only in foods derived from plants
• soluble fibres like pectins, gums, mucilage are found in fruits, vegetables, oat bran, barley and soy products
• soluble fibre intake :

  • Prevents absorption of fats by trapping them which lowers cholesterol
  • Decreases risk of heart disease and cancer
  • Has beneficial effects on blood glucose levels
• Constipation is a condition in which defecation is difficult, with faeces being hard and dry
• constipation occurs if movements of large intestine are reduced, causing contents stays for long time and more water is absorbed. this makes the faeces harder and drier, making defecation more difficult and possibly painful
• constipation is caused by

  • lack of roughage (cellulose / insoluble fibre from plants) ; cellulose is important to stimulate the movements of alimentary canal
  • lack of exercise
  • emotional problems
• Diarrhoea is the frequent passing of watery faeces. If severe, it can cause dehydration and even death
• diarrhoea is caused by irritation of small intestine or large intestine, which increases peristalsis causing the contents to be moved through before adequate absorption of water
• diarrhoea is caused by irritation of the small or large intestine through : 

  • Bacteria - E.coli, salmonella
  • Virus - norovirus, rotavirus
  • Parasite - giardia
  • Cancer - bowel
  • Coeliac disease
  • Lactose intolerance
• Bowel (colorectal) cancer is cancer in the colon and rectum. Uncontrolled growth of cells in the wall of the large intestine
• bowel cancer is caused by :

  • diet high in red and processed meat, low in fibre
  • overweight / obese, physically inactive
  • high alcohol consumption + smoking
• Coeliac disease is an autoimmune disease due to the immune system reacting to gluten
• people with coeliac disease immune system damages or destroys villi in small intestine when gluten is eaten, meaning nutrients cannot be absorbed, they therefore become malnourished no matter how much food
• symptoms of coeliac varies between people but may include :

  • Muscle cramps
  • Joint pain
  • Tingling in legs
• coeliac is inherited. there is no cure, the only treatment is to follow a gluten-free diet
• Speed of movement of material is dependant on size and contents

  • a large meal causes greater stretching in the stomach, causing material to be pushed into the small intestine quicker than when stomach is less expanded
  • High protein and/or high fat content slows movement from stomach to small intestine
  • Alcohol and caffeine stimulate movements of stomach