UNIT 1
AN OVERVIEW OF NUTRITION
Introduction
• Daily food choices
a. Benefit health
b. Harm health (chronic disease)
• Diet
a. Not referring to restrictive weight-loss plan
b. Foods and beverages
Food choices are highly personal
• Personal preference (taste: sweet and salty, genetics)
• Habit
• Ethnic heritage or tradition
• Social interactions
• Availability, convenience, and economy
a. Benefits of home-cooked meals
b. Cost
• Positive and negative associations
Food choices: other factors
• Emotions (boredom, depression, anxiety, stress)
• Values (religious beliefs, environmental concerns)
• Body weight and image
• Nutrition and health benefits (whole foods, minimally processed foods, ultra-
processed foods)
The nutrients
• Water: hydrogen and oxygen, inorganic (no carbon)
• Minerals: simplest nutrient, inorganic
• Vitamins: organic (contains carbon)
• Carbohydrates: organic
• Proteins: organic (contains nitrogen)
• Lipids (fats): organic
,Body composition of healthy-weight men and women
The six classes of nutrients
Energy- Macronutri Micronutri
Nutrient Organic Inorganic
yielding ent ent
Carbohydra
✓ ✓ ✓
tes
Lipids (fats) ✓ ✓ ✓
Proteins ✓ ✓ ✓
Vitamins ✓ ✓
Minerals ✓ ✓
Water ✓
Energy in the body
• Body uses macronutrients
• Bonds between the nutrients’ atoms break (energy is released, can be used or
stored)
• Macronutrients
a. Provide raw material for building tissue and regulating body activities
b. Proteins regulate digestion and energy metabolism
The vitamins
• Thirteen organic vitamins, each has a special role
• Facilitate energy release, almost every bodily action requires assistance from
vitamins
• Vulnerable to destruction (heat (from cooking), light, and chemicals)
The minerals and water
• Minerals
a. Sixteen essential minerals
b. Other minerals are environmental contaminants e.g. lead
, c. Indestructible (can leach into water during cooking, may be lost during food
processing
• Water is the environment for nearly all body processes
The science of nutrition
• Foundation in several other sciences (biology, biochemistry, physiology)
• Tremendous growth
• Knowledge gained from sequencing the human genome (nutritional genomics)
Conducting research
• Use of scientific method (systematic process for conducting research)
• Research studies
a. Controls (randomization)
b. Sample size
c. Placebos
d. Double-blind experiments
The scientific method
• Research scientists follow the scientific method. Note that most research
generates new questions, not final answers
• Thus, the sequence begins anew, and research continues in a semi cyclical way
, Types of research
Epidemiological studies
• Cross-sectional studies
• Case-control studies
• Cohort studies
Experimental studies
• Laboratory-based animal studies
• Laboratory-based in vitro studies
• Human intervention (clinical) trials
Analyzing research findings
• Correlations (only show association, a positive correlation is not necessarily a
desired outcome, can also be a negative correlation or no correlation)
• Cautious interpretations and conclusions (accumulation of evidence)
Publishing research
• Peer review (assess research validity prior to publication)
• Newly published findings (are preliminary and not meaningful alone)
• Findings are confirmed or disproved through replication and reanalysis
Dietary reference intakes (DRI)
• To best support health, results from thousands of research studies are used to
produce a set of standards that define amounts of:
a. Energy
b. Nutrients
c. Other dietary components
• Collaborative effort between United States and Canada
