Quiz 3 Flashcards
Energy Balance
balance the calories consumed through eating and drinking compared to calories burned
Weight maintenance
E in = E out
Weight gain
E in > E out
Weight loss
E in < E out
What is the result of a short period of positive energy balance?
- Short-term weight gain
How does the body prevent the continuous increase of weight?
- increasing resting energy expenditure
- hormone regulation
- thyroid regulates metabolic rate
- Increase the energy cost of performing an activity
Gaining weight from positive energy balance =
increase in fat mass
Can carbs be converted into protein or fat
- unlike animals, humans have insufficient enzymes to do so
- there is some conversion only
Limited storage:
carbs and proteins
Carbs stored as glycogen ( 2 pounds max)
excess carbs and protein expended first, fat gets stored without being used as fuel
What is the estimation of healthy weight? Men
106 pounds for first 5 ft. + 6 lbs for every inch over that
What is the estimation of healthy weight? Women
100 lbs for the first five ft. + 5 lbs for every inch over
Macronutrients ( large quantities):
- Energy providing nutrients ( calories)
- Carbs, proteins, Lipids
Carbs
- Major source of fuel for body in exercise
- starches and sugars
- food sources: grain, veggies, legumes, fruits, dairy
Proteins
- Building blocks of life - amino acids combine = proteins
- some proteins are essential ( can’t be made so must be in the diet)
- Food sources: animal sources, dairy, legumes and grains
Lipids
- bad fats and good fats
Bad fats:
- Trans fats- worst dietary fat ( margarine, shortening)
- Saturated fats- Common in the American diet ( red meat, whole milk)
- trans and saturated fats increase the risk of heart disease
- protective against heart disease
Good fats:
- From veggies, nuts, seeds, fish
- monosaturated fats ( ex. olive oil)
- polyunsaturated fats ( ex. corn oil)
Micronutrients( smaller quantities):
- Vitamins, minerals
Vitamins:
regulate bodily processes, keep organs and tissues functioning, and promote growth
- blood clotting, calcium balance
Do not contribute energy ( help with the extraction of energy)
Fat-soluble and water soluble in the body ( water-soluble lost daily)
Minerals and Water
- 16 minerals are essential to health
- deficiencies are uncommon, except calcium and iron
- Water is chemically the simplest nutrient, most important
- can survive loner without any other nutrient than we can survive w/o water
How much of our bodies are water?
60%
Top sources of calories in Americans 2 years or older
- Grain-based desserts
- Yeast breads
- Chicken and chicken mixed dishes
- Soda/energy/sports drinks
- Pizza
Code words for sugar:
- brown sugar
- cane juice and cane syrup
- confectioners sugar
- corn sweeteners and corn syrup
- dexrose
- fructose
- glucose
- high fructose corn syrup
Whole Grains:
- unrefined grains that haven’t had their bran and germ removed by milling - low glycemic index
- more fiber and important nutrients
- brown rice, ingredients such as buckwheat
Refined grains:
- milled to give them a finer texture and extend their shelf life- no bran and germ
- the refining process removes many nutrients and fiber
- white flour, white rice, white bread, and degermed cornflower
- enriched and fortified at times
Daily Value %
- 5% or less is low
- 20% or more is high
Mediterranean Diet
- high in fruits, veggies, wholegrains bread, rice and pasta, potatoes, beans, nuts and seeds
- Olive oil as an important fat source and fat from dairy products, fish, and poultry ( consumed in low- moderate amounts)
- eggs in moderate amounts, and low amounts in red meat in low amounts
- wine is consumed in low to moderate amounts
Where does the Mediterranean diet originate?
American scientist Ancel Keys pointed out the correlation between cardiovascular disease and diet in the 1950s
- Seven countries study
What evidence did the seven countries’ study provide?
- cardiovascular risks are universal
- diet-heart hypothesis
- preventable
- A healthy lifestyle may promote different aspects of health `
DASH- Dietary Approach to Stop Hypertension
- emphasized veggies, fruits and low fat dairy ( moderate amounts of whole grains, fish, poultry and nuts
Standard DASH diet:
2300 mg of sodium a day
Lower sodium DASH diet:
Consume up to 1500mg sodium a day
What is intermittent fasting
- specifies when you should not eat certain foods
- eating pattern that cycles between periods of fasting and eating
- currently popular
History of Intermittent fasting:
- Practice throughout human evolution. Hunters-gatherers
- evolved to function without food for longer periods of time - several people consider fasting from time to time as more natural than eating 3-4 meals a day
- often done religiously as well
- animal studies
- E restriction study: prevents cancer
Energy restriction is difficult to achieve more to maintain:
- 25-30% adherence ONLY to low cal diets at 12 months
- 20-240% achieve> 5% weight loss at `1 year
- Only 20% of women at high risk of breast cancer maintain > 5% weight loss a 5 years with restriction diets
How does fasting affect body?
- Fasting for 14 hrs makes body burn body fat due to lowering of blood sugar or carbs
- rapid loss of fat ny fasting 14-20 hours per day = metabolic switching
- progress slowly, not advised to jump straight into 24-23 hr fasts
Metabolic switching:
liver-derived glucose to adipose cell-derived ketones
What are the most popular methods of intermittent fasting?
- 16/8 method ( Leangains protcol)
- Eat- Stop- Eat method
- 5:2 diet
In the research who lost more fat the Intermittent dieters or the daily dieters?
Intermittent dieters lost more fat ( 6kg v.s 4.9 kg)
The intermittent diet had beneficial effects on metabolism during and after restriction days. True/ False
True.
- better at reducing insulin on “non-diet day”
- additional 25% reduction on insulin on diet days
What positive changes did intermittent fasting have?
- improved glucose regulation
- stress rsistance
- suppresses inflammation
- cells activate pathways that enhance intrinsic defenses against oxidative stress and those that remove or repair damaged molecules.
Bariatric Surgery:
- restrictive surgery - restricts amount of food ingested (decreases appetites)
- Malabsorptive: limits digestion and absorption –> decreases the length of intestine exposed to the food ( reduces fat absorption by 2%)
- Surgery is always accompanied by behavior modification - diet and exercise
Sleeve gastrectomy:
- Resection of 80% of the greater curvature side of the stomach
- smaller tubular sleeve is created
- causes weight loss through mechanical restriction and hormonal modification
Ghrelin
- hunger hormone
- lowered in sleeve gastrectomy
Mechanical restriction:
reducing volume and stomach motility
Intra- Gastric Balloon:
- deflated balloon placed in the stomach, filled to decrease stomach space
- left in stomach max 6 months
- typically used prior to other surgery
Why measure body comp?
- change in body fat weight due to weight loss programs
- athletes : performance
- monitor weight in diseased patients
- Track long term changes with aging
Essential Fat
necessary for normal functions
- bone marrow
- cell membranes
- organs
- fat rich tissues in the CNS
- 2-5% in men / 10-13% in women
Storage Fat:
Adipose tissue = storage fat
- located around internal organs
- Subcutaneous
fat cell growth: Hypertrophy
- increase in size
- excess triglyceride fat accumulation in existing adipocytes
fat cell growth: hyperplasia
- increase in number
- results from the recruitment of new adipocytes from the precursor cells in fat tissue
BMI:
- Common way to classify obesity
- Body mass index = (weight in kg)/height in m^2
- composite # used to define obesity
- does not take into account lean body mass
- effective screening tool - it’s not diagnostic
Childrens BMI:
- For children 2-19 yrs old BMI is age and gender-specific
- tracks childhood overweight into adulthood
2-compartment model:
- Fat mass
- fat-free mass
3-compartment model:
- fat mass
- fat-free mass
- bone ( mineral) mass
4- compartment model:
- fat mass
- fat-free mass
- water mass
- bone (mineral) mass
Underwater weighing:
- a person is weighed on land and in the water tank to determine BODY DENSITY
Basics of Underwater weighting:
- Archimedes Principple
- lean tissue = greater density than water
- fat tissue = lower density than water
= A person with more body fat will weigh less underwater than a person with more lean tissue
Bioelectrical impedance:
- electric current flows through the body and resistance is measured
Basics of Bioelectrical impedance:
- more muscle= greater amount of water the body can hold = less resistance
- more fat= less water= more resistance
Air displacement plethysmograph-
BodPod
Utilizes displacement of air within a closed chamber (Bod Pod) and
pressure-volume relationships (Boyle’s Law) to estimate BV
DXA measures:
Distinguishes between
- bone
- soft tissue ( muscle and fat)
Measuring Body Fat
- skinfold thickness measurements, using calipers to measure fat under the skin
- based on the direct correlation between subcutaneous fat and whole-body fat.
