Biochemistry 9 Flashcards
What is nutrition?
the study of food (diet), its digestion, absorption and utilization for growth, repair, and metabolism
Food composition
nutrient dense vs. ultra-processed
Nutrition is the balance between
amount of caloric intake and energy expenditure (calories out)
People with a higher body mass index has poorer outcomes with
COVID-19
Why should physicians study nutriition?
patient education, many patient visits to PCP involves at least one question about nutrition.
Where can your patients find reliable information?
- Refer a patient to a dietician
- Government entities
- Professional Associations
- Primary literature
General guidelines for health promotion
- Focus on amount, variety, and nutrient density (vitamins, minerals, and other health promoting components) of food
- Include at least 150 minutes of physical activity per week
- Include both aerobic and muscle strengthening activity
this gets more important as your patients get older
We should limit dietary
- Sodium
- Saturated fats
- Added sugar
What is naturally occurring sugar?
Vegetables, fruits, milk, vitamins, minerals and fibers (helps to avoid big spikes of sugar into your circulatory system)
Macronutrients
-Determine nutrient needs
-Understand nutrient labels
-Calories as a measure of energy content
-Energy expenditure from rest, physical activity, and the thermic effect of food
ex: carbohydrates, fats, proteins, vitamins, and minerals
What is added sugar?
processed foods and beverages, excess sugar can lead to increased fat stores
Nutrients definition
Components of food necessary to sustain the normal functions of the body
DRI
Dietary Reference Intakes (DRIs) estimate the amount of nutrients needed to prevent deficiency and maintain optimal health
EAR
Estimated Average Requirement. Meets the needs of half the population
RDA
Recommended dietary allowance. EAR plus 2 standard deviations (97-98% of the population). Risk of inadequacy and adverse effects is low.
AI
Adequate intake, used when there is no EAR. Range of predicted values for healthy people. No predictable relationship to the EAR or RDA
UL
nutrient levels greater than the UL are unsafe
Different populations have different?
Dietary needs
The FDA regulates all aspects of this label, and it will be found on packaging for
processed foods and ultra-processed foods
Processed foods
added sugar, fat and or salt
-examples: canned fruit/vegetables, simple bread, cheese
Ultra-processed food
many added ingredients such as sugar, salt, fat, and artificial colors or preservatives
-ex: soft drinks, chips, cookies, hot dogs
serving size is NOT meant to be
a recommendation
Daily value (DV) is the
weighted average of nutrients RDA or AI
RDA for calcium
1,300 mg/d
Percent daily failure (%CV)
the amount of nutrient in one serving of food expressed as s percentage of the DV
260 mg calcium / serving / 1300 mg DV
20% DV in one serving
Choose fats low in
-Saturated fat
-Trans fat
-Cholesterol
-Sodium
-Added sugar
Choose fats high in
Fiber
Vitamin D
Calcium
Iron
Potassium
%DV is used to evaluate
nutrient content
0-5%, 10-19%, and 20% of nutrient content
low, good, and high sources
FDA regulates
-manufacturer’s claims about the quantity of a nutrient/serving based on the %DV
-These types of claims can also include product comparisons
Health claims describe the?
“potential” relationship between a FOOD substance (a food, food component, or dietary supplement ingredient) and REDUCED RISK of a disease or health-related condition
Health claims are based on a?
rigorous review of scientific literature and are rightly regulated by the FDA
There are 12 approved health claims such as
fluoridated water reduces the risk of dental caries
Labels: Structure/Function Claims
describe a relationship between a nutrient and normal structure or function of the human body
labels cannot
claim to diagnose, cure, treat, or prevent disease
Structure/function claims do not
require pre-approval from the FDA, they are protected by the First Amendments’s “right to speech.”
GMO
a plant, animal, or microorganism that has had its genetic material (DNA) changed using technology
GMOs are considered
safe for your health and environment
Most common traits for GMO crops
resistance to insect damage, tolerance to herbicides, resistance to play viruses
(ex: bacterial gene inserted into corn, soybeans, and sugar beets resulting in them being resistant to the weed killer)
BE disclosure
as of January 2022, foods that contain
detectable genetic material that has been modified through certain lab techniques (in vitro recombinant DNA) and cannot be created through conventional breeding or found in nature
Items except from BE labeling
-Highly processed foods that do not contain DETECTABLE levels of rDNA (refined sugars and oils from GMO sugar beets, soybeats, and canola)
-Meat from livestock fed GMO feed
-Spirits or beer that are distilled or brewed from GMO grains or potatoes
(Foods from the initial source)
To earn the label of organic foods
Farmers must adhere for 3 years
1. Utilize compost and sustainable practices (RRR)
2. No synthetic fertilizers, herbicides, pesticides, or antibiotics
Good for the soil and environment, but labor intensive and expensive
Nutrient value is the same between organically or conventionally raised crops
“Natural” foods are not the same. Just means no artificial color, flavor, or preservatives.
EER
Estimated Energy Requirement (EER) is the average dietary intake predicted to maintain an energy balance.
How do we know the energy content of food?
Bomb Calorimeter, energy is measured by the heat released from the total combustion of food
Raising the temperature of 1 gram of water by 1 degree Celcius =
1 calorie
Standard nutrition units are
kilocalories (kcal or Cal)
Raised 1000g water by 1°C
Fuel factors
standard conversion factors for determining the metabolic calorie value of macronutrients
Fuel factors allow us to calculate
calories based on grams of macronutrients in food
Dietary fiber (soluble and insoluble)
affects digestion and absorption which alters the bioavailability of nutrients
Bioavailability
portion of consumed nutrient that is absorbed
Fiber delays? Increases? Reduces?
delays gastric emptying
increases sensation of fullness (satiety)
reduces spikes in blood glucose following a meal
Fiber draws fluid into the lumen of the?
Intestine. Increases bowel motility and promotes bowel movements.
Fiber interacts with?
Bile acids, affecting reabsorption. Increases fecal bile and lowers LDL-C levels.
Actual calorie count may differ from?
what’s listed in the tables because of variations in digestion and absorption which affect bioavailability of nutrients
TEE (Total Energy Expenditure) Determines
Daily Caloric Needs
TEE is the number of?
kcal expended frmo the sum of the following three processes in a 24 hour period: RMR, PA, TEF
Equation for Metabolism
Direct calorimetry
Estimates RMR by measuring the heat produced by metabolism from a body mass in an enclosed chamber. Accurate measures over time (hours).
Cons: expensive, cumbersome, time-consuming.
Indirect calorimetry
estimates RMR by measuring respiratory gases (oxygen consumption and carbon dioxide release)
- Most common in a clinical setting; measurements in minutes
Mathematical Formula
-Generalized assumptions to estimate RMR (i.e., lean muscle mass differences between men and women)
-Will not be as accurate because people are complex (i.e., athletes,
disease state, etc.)
RMR represents the?
energy required to run the body’s infrastructure and is the biggest component of TEE
Examples of RMR
Body temperature, central nervous system, internal organs, protein turnover, and ion transport
RMR reported as the number of kcal used in?
24 hours by a fasting individual at rest
Men RMR
body weight (kg) x 1 kcal/kg/hr x 24 hours
Women RMR
body weight (kg) x 0.9 kcal/kg/hr x 24 hours
Physical activity reflects
any movement of the body caused by muscular contraction and is arbitrarily divided into two types
1. exercise
and 2. non-exercise activity thermogenesis (NEAT)
exercise
bodily exertion for the sake of developing or
maintaining physical fitness
Nonexercise Activity Thermogenesis (NEAT)
all other physical movement for daily activities such as walking, talking, fidgeting, etc.
NEAT is the predominate aspect of physical activity
Calculating the caloric cost of physical activity can be performed for:
specific task - MET and average activity level
MET
ratio of the metabolic rate determined during the task divided by the individual’s RMR
Standard convention of MET
1 MET = 1kcal/kg/hr
METs can be used to estimate
energy spent when engaged in various activites
MET value equation
MET value x body weight (kg) x duration (hrs) = kcal
Necessary calories needed for general activity levels are estimated as a percentage of an individual’s
RMR
Active energy cost x RMR =
kcal
TEF (Thermic Effect of Food)
increase in the metabolic rate induced by eating
Hypothesized that TEF represents the energy?
spent to digest, absorb, distribute, and store ingested nutrients
finish later.
