Chapter 1: The Science of Nutrition
Fact or Fiction?
Eliminating all fat from the diet will improve
Avoiding carbohydrates will lead to weight
Protein is the most important nutrient. As long as you take a vitamin and mineral pill each day
you don’t have to worry about eating healthy.
Our genes determine our weight.
Low fat or
Example: Be Well Buzz:
fat-free plain yogurt Eggs Nuts Kiwis Quinoa Beans Salmon Sweet potatoes Berries
1 slice whole wheat bread: 22 g 1 banana 27 g 1 medium potato 33 g 1 cup cooked pasta 43 g 1 apple 19 g 1 can soda 35 g 20 -
Why study nutrition?
Over the last two decades:
Percentage of obese adults doubled (33 %) Percentage of overweight children doubled (16 %) Percentage of overweight adolescents tripled (16%)
Leading Causes of Death in 1997 and 1900
Leading causes of death
Major health problems are largely causes by poor diet
How are genetic traits passed from one generation to another?
The DNA sequence (genome) does not change and is passed on to the next generation. But: The access to the DNA changes biochemically and can be passed on to the next generation.
DNA Methylation Methyl groups added to certain DNA bases represses gene activity
Histone Modification Molecules attached to histone tails alter DNA activity.
Genes and Nutrition
Nutrition related diseases
We have control over our DNA.
Control can be passed on to the next
How nutrition effects gene expression and
Food stimulates short-term gene expression.
Vitamins and minerals can stabilize or
intake of biotin, riboflavin destabilize High intake of vitamin E, retinol, calcium stabilize Impaired intake of folate, B6 induces DNA breaks
How genetics effects nutrient utilization.
Systems Biology Approach
How all components of a biologic system interact over time under varying conditions.
Group of scientist with varying expertise
Examples: Nutrigenomics, proteomics,
Assess your Risk
High Risk: More then one first degree relative with certain condition Condition occurs before
age 50 – 60 years
Use family tree to asses your own
Diabetes, obesity, certain cancers, osteoporosis, hyperlipidemia, hypertension
The Science of food Action, interaction and balance of nutrients in
relationship to health and disease
Process of ingestion, digestion, absorption,
transport, utilization and excretion of food substances
Nourishing substances 6 classes of nutrients :
Carbohydrates Lipids Protein
Vitamins Minerals Water
Specific biological function. Removing from diet leads to decline in biological body
Adding to diet before permanent damage is done
restores biological body function . Example: Vitamin C, sodium, niacin, fluoride
Body is able to make these in sufficient
amounts when they are needed.
Humans do not need to consume these.
Provide Energy Most carbohydrates Proteins Promote Growth and Development Proteins Lipids Regulate Body Processes Proteins Some lipids
Some minerals Water
Some minerals Water
Macronutrients vs. Micronutrients
Energy yield: 4 kcal/g
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