Fndm revise

• Essential


  Exclusion - death = essential, Cannot be synthesised in the body from other nutrients
• Non-essential


  The body can synthesise from other nutrients
• Categories of nutrients


  • Macronutrients (Protein, Fat, Carbohydrate, Alcohol)
  • Micronutrients (Vitamins and Minerals)
• Protein


  • Structural - bone, muscle, skin, cell structure
  • Molecules - enzymes, hormones
  • Energy - directly and indirectly
• Amino acids (AA's)


  22 commonly found in animal tissue, 9 are essential to man
• Essential amino acids


  • Threonine
  • Methionine
  • Lysine
  • Valine
  • Leucine
  • Isoleucine
  • Histidine*
  • Phenylalanine
  • Tryptophan
• Non-essential amino acids


  Formed 'endogenously' by 'transamination' reaction
• Complete and incomplete proteins

  Limiting amino acids
• Fats


  • Structural component - cell membranes
  • Provides insulation/padding
• Essential Fatty Acids (EFA's)


  Linoleic/Alpha-Linolenic, 'Eicosanoid' precursors, Carriage of fat soluble vitamins
• Carbohydrates


  40-75% dietary energy, Sugars, Starches, NSP's, Fibre
• Carbohydrates


  • Non-essential (glucose synthesised by the liver), Energy provided by AA's and fat, Desirable qualities - traditional place in cuisine, provision of micronutrients/fibre, palatability, easily stored, acts as a preservative
• Vitamins


  • Organic compounds (essential in small amounts) for life, Classified as water or fat soluble and alphabetically (A,B,C,D,E,K), Function as co-enzymes and antioxidants
• Minerals


  • Inorganic elements essential (in small amounts) for life, Major components of teeth and bones, Components of metalloenzymes, Ionic/electrolytic, Functions - muscle contraction (Ca), oxygen transport (Fe), nerve impulse conduction (Na, K)
• Water


  • Essential component of life, Required for all bodily processes, Body composition: 45% -75% (average 60-70%), Intracellular fluid, Extracellular fluid
• Essential roles of water

  Basis of saliva, Synovial fluids, Medium for chemical reactions, Waste removal
• Dehydration


  1% or greater loss of body mass due to fluid loss, Can impair cognitive function and physical performance, Associated with CHD, high BP, UTI's
• Over-hydration


  Can cause low levels of sodium in the blood "Hyponatraemia", Brain swelling, headache, fatigue, lethargy, confusion, vomiting, seizures
• Dietary sources of water

  Not just drinking "Tap" or "bottled", All foods and beverages, % water varies e.g soups (80%), fruit and veg (40%), between 10-40% dried products, Food versus beverages: rate of absorption differs
• Water content of commonly consumed foods and drinks
• Water requirements


  Depends upon: Climate, Gender, Body mass, Age-phase of lifecycle, Other compounds within beverages
• Current water intakes
• Water intake recommendations


  No Single upper tolerable level, EFSA Draft DRVs: adult men 2.5litres/day; adult women: 2 litres/day, Food Standards Agency/ Eatwell Guide: 6-8 glasses a day
• Healthy eating


  Flexible notion, not a fixed combination of nutrients, Able to support growth, reproduction, good ongoing and physical mental health
• Different diets that achieve healthy eating aims

  • Mediterranean, Japanese, Strict vegetarian, Inuit (eskimo), Trad. Masai
• Assessing dietary intakes


  • Measuring food & drink intake, Food composition tables, Dietary reference values and nutritional guidelines, Biomarkers, Human studies and trials
• Dietary assessment methods


  • 24hr recall
  • Surveys
  • Food frequency questionnaires
  • Dietary records (weighed/estimated)