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Food  Choices:  Nutrients  and  Nourishment  

BIOL  103  Chapter  1  

What  is  Nutri<on?  

•  The  science  of  foods  (e.g.  nutrients  and  other  substances),  including  the  rela<onships  to  health  and  disease;  processes  within  the  body  (inges<on,  diges<on,  absorp<on,  transport,  storage,  func<ons,  and  disposal  of  end  products);  and  the  social,  economic,  cultural  and  their  components,  and  psychological  implica<ons  of  ea<ng.  

Factors  that  Influence  Food  Choices    

1.  Sensory  2.  Cogni<ve    3.  Gene<cs  4.  Environmental  5.  Health  status    

Why  do  we  eat  the  way  we  do?  

•  Sensory    1. Flavor/Taste  

2. Texture  

3. Appearance    

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Why  do  we  eat  the  way  we  do?  

•  Cogni7ve  1. Learned  food  habits/food  reward  

2. Social  factors  3. Comfort/discomfort  foods  

•  Behavioral  mo<ves  

4. Adver<sing  5. Nutri<on  and  health  beliefs  

Why  do  we  eat  the  way  we  do?  

•  Environment  1. Economics    2. Lifestyle    3. Availability    4. Cultural  Influences      5. Religion  

The  American  Diet  •  “Meats and potatoes” •  Americans age 2 and older

consume, on average, 2157 calories (based on 2000 calories diet)

•  How healthful is the “American” diet?

Too little: fruits, dairy, vegetables, whole grain foods

Too much: saturated fat, sodium, and sugar

Nutrients    

•  Defini<on:  Any  substance  that  provides  nourishment  essen<al  for  growth  and  the  maintenance  of  life.  

•  Essen<al  vs.  Non-­‐essen<al  nutrient  – Essen7al  nutrient:  ______________________  – Non-­‐essen7al:    _________________________    

•  How  to  determine  if  it  is  an  nutrient?  

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The  six  classes  of  nutrients  (Problem  Set#1,  Q2)  

1.  Carbohydrates    2.  Proteins  3.  Lipids  (fat)  4.  Vitamins  5. Minerals  6. Water  •  Macronutrients  vs.  Micronutrients  

General  Func<ons  of  Nutrients  (what  do  they  do  in  our  body)  

1.  Provide  ____________  2.  Regulate  ____________  processes  3.  Build  ______________  body  structures  

What  does  Organic  mean?  

•  Organic  or  Inorganic?    – What  does  it  mean  if  food  is  organic,  in  science?    

Carbohydrates  •  Carbohydrates:  “hydrate  

of  carbon”  –  Made  of  sugar  molecules  

•  Func<on:    –  ________________  for  cells  and  <ssues  

•  Dietary  sources:  starches  and  sugars  found  in  grains,  vegetables,  legumes  (dry  beans  and  peas),  fruits,  dairy  products  

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Lipids  •  Lipids  (fats,  oils,  cholesterol,  

phospholipids)  –  Made  of:  ______________  

______________________  •  Func<ons:    1.  Energy  storage  as  triglycerides    2.  Carries  fat-­‐soluble  vitamins    3.  Provides  structure  for  body  

cells  •  Food  sources:  fats,  oils,  

meat,  dairy,  some  plants  (avocado,  coconut)  

Proteins  

•  Made  of:  ____________  •  Func<ons:    1.  Energy  source  2.  Structure  for  cells/<ssues/

body  structures  3.  Regula<on  of  body  

processes  

•  Food  sources:  meats,  dairy  products,  grains,  legumes,  vegetables.  

Vitamins  •  Made  of:  carbon,  hydrogen,  

and  any  one  or  combo  of  the  following  (N,  O,  P,  S,  or  other  elements)  

•  Func<ons:    1.  helps  regulate  body  

processes  2.  help  extract  energy  from  

carbs,  fat,  and  proteins  •  Food  sources:  meats,  

vegetables,  grains,  dairy,  fats  

Fat  vs.  Water-­‐Soluble  Vitamins  

•  Fat  Soluble  Vitamins  –  Stored  in  larger  quan<<es  

 

•  Water  Soluble  Vitamins    

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Minerals  

•  Inorganic  substances  •  Func<ons:  

1.  Structure    2.  Regula<on    

•  Food  sources:  all  food  groups  

Dietary  Minerals  

– Macrominerals:  Na,  Cl,  K,  Ca,  P,  Mg  – Microminerals    or  “trace  minerals”:  Fe,  Zn,  Cu,  Mn,  Mo,  Se,  I,  Fl    

Water  

•  Most  important  nutrient  J  

•  Func<ons:  1.  Temperature  control  2.  Lubrica<on  of  joints  3.  Transporta<on  of  

nutrients  and  wastes  

•  Food  sources:  beverages,  foods  like  fruits  and  vegetables.  

Macronutrients  

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Macronutrients:  From  Food  to  Fuel   Energy  in  Food  •  We  eat  nutrients  so  that  we  can  gain  energy  –  Energy:  capacity  to  do  work  – Q:  Which  nutrients  contain  sources  of  poten7al  energy?  

 •  Kcal  vs.  Calories  •  How  do  we  measure  energy  in  Nutri<on?  –  Kilocalories  (kcal)  

•  1000  calories  =  1  kilocalorie  •  1  kcal:  the  amount  of  energy/heat  needed  to  raise  the  temperature  of  1  kilogram  (kg)  of  water  by  1  degree  Celsius.  

Energy  in  Food  Use calorie as a general term for energy and kilocalorie as a specific measurement or unit of that energy.  

Problem  Set  #1,  Q3  

•  A)  Jeff  is  ea<ng  a  snack  with  20g  of  carbohydrates,  5  grams  of  proteins,  and  3  grams  of  fat.  What  is  the  total  amount  of  available  energy  (in  kcal)  in  his  snack?  (Note:  you  will  need  to  show  your  work  for  full  credit  in  an  exam).  

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Problem  Set  #1,  Q3  

B)  Determine  the  percentages  of  kilocalories  of  carbohydrate,  protein,  and  fat  in  Jeff’s  snack.  

Many  of  the  leading  causes  of  death  can  be  avoided  by  good  diet  and  exercise  

More  than  2/3  of  U.S.  Adults  are  overweight/obese   Diet  and  Health  

•  Healthy:  “a  state  of  complete  physical,  mental,  and  social  well-­‐being  AND  not  merely  the  absence  of  disease  or  infirmity.”  (WHO)  

•  Disease  – Acute:  ____________________________  •  Examples:    

– Chronic:  __________________________  •  Examples:  

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Diet  and  Health  

•  Factors  that  influence  Obesity:  1. Behavior  

1.  Calorie  imbalance  2.  Sedentary  lifestyle  

2. Environment  •  Barriers  to  or  opportuni<es  for  an  ac<ve  lifestyle  

3. Gene<cs  •  Role  of  heredity  

 

Diet  and  Health  

•  Physical  Ac<vity  – Role  in  long-­‐term  weight  management    •  At  least  ____  mins/day  of  moderate  ac<vity    

– Weight-­‐management  •  At  least  ____  mins/day  of  moderate  ac<vity  

– What  is  moderate  ac<vity?  

 

Common  Study  Designs  used  in  Nutri<on  Research    (PS#1,  Q  4  and  5)  

1.   Cell  culture  studies:  effect  of  nutrients  on  cells    2.   Animal  Studies:  effect  of  nutrients  on  animals    3.   Epidemiological  studies:  study  of  disease/death  rates  

in  popula<on  groups    4.   Case  Control  Studies:  disease  vs.  those  without  disease    5.   Clinical/Interven7on  Trials:  experimental  vs.  control  

group  –  Placebo-­‐controlled  

   

Junk  Science  

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Evalua<ng  Informa<on  on  the  Internet  

•  There  are  no  rules  for  pos<ng  on  the  internet  •  Consider  the  source  •  Keep  in  mind  the  scien7fic  method  •  Be  on  the  lookout  for  “junk  science”  – May  distort  facts  through  omission  of  details