Lecture 11 Flashcards
1
Q
eating behaviour regulated by:
A
-signals and mechanisms that stimulate eating
-signals and mechanisms that to stop eating or lead to refrain from eating
2
Q
hunger
A
-unpleasant sensation that signals for food
-4-6hrs after eating
-food has left stomach & nurtients absorbed
3
Q
what triggers hunger
A
-triggered by contracting empty stomach and empty small intestine
-triggered by stomach hormone ghrelin
4
Q
what drives eating
A
appetite
5
Q
appetite
A
-phychological desire to eat
-experienced without hunger
-stimulated by sight & smell of food
-illness or stress may result in loss of appetite
6
Q
factors affecting appetite
A
-hormones
-inborne appetites
-learned preferences
-habits
-social interactions
-disease states
-stimulates & drugs
-environement conditions
7
Q
satiation
A
perception of fullness, determines how much food is eaten in a sitting, stretch receptors in stomach send signals to brain
8
Q
satiety
A
suppresses hunger, determines length of time between meals, perception of fullness lingering after a meal
9
Q
sensory specific satiety
A
-concept that we tend to get bored of a food as we eat it
-more variety=more likely we will increase overall consumption
10
Q
buffet
A
people generally overeat
11
Q
are hunger and satiety equal
A
no - hunger is stronger
12
Q
Leptin
A
- a satiety hormone
–appetite-suppressing
-produced by adipose tissue in stomach
-travels to brain
-directly linked to appetite control & amount of body fat
13
Q
gain of body fat stimulates
A
leptin production> reduces consumption resulting in fat loss>reduces leptin secretion increasing appetite
14
Q
studies on glycemic index
A
some show low-glycemic index diet reduced or delayed hunger, other found opposite or no effect
15
Q
of the energy yielding nutrients, which is the most satiating
A
protein
16
Q
fat is known for its effect on
A
satiety
17
Q
protein & fat trigger release of
A
intestinal hormone (CCK) that slows stomach emptying and prolongs feelings of fullness
18
Q
fat
A
-weak effect on satiation
-provides a lot of kcals in small volume
19
Q
Theories of metabolic causes of obesity
A
- Set point theory
- Fat cell number theory
- Thermogenesis 1: brown fat theory
20
Q
set point theory
A
body somehow attempts to maintain a stable body weight
21
Q
fat cell number theory
A
fat cells may increase faster in children who are obease contributing to obesity as adults
22
Q
Thermogenesis 1: brown fat theory
A
brown fat (brown adipose tissue) has abundant energy wasting protiens. lean people have more brown fat, infants have abundant brown fat
23
Q
genetics & obesity
A
-in rare cases, primary cause of obesity is genetic
-infleunce how body stores & uses energy
-genes not solely responsible
-adopted people have similar weight to birth parents
24
Q
likelihood of genetic obesity
A
if a child has 1 parent obease, they are 40-70% likely to be obease
25
if genetics causes obesity, why have obesity rates skyrocketed when gene pool remains same
while genetics influences a persons tendency to become obease, lifestyle choices determine if tendency is realized
26
out side body potential causes of overweight/obesity
-people override signals of satiation/satiety
-variety
-in response to something (stress)
-food price/availability
-physical inactivity
27
obesogenic environment
all the factors surrounding a person that promote weight gain
28
for some people who are choosing to reduce their weight, a way to obtain a healthy body weight is to:
-maintain balanced diet
-engage in daily PA
-pharmalogical therapy
-physical intervention
29
what determines weight
the balance between energy intake & energy output determines whether you gain, lose or maintain body fat
30
slight/rapid change in weight
-body fluid content
-bone minerals
-muscle
-bladder or digestive tract contents
**change often correlates with time of day
31
weight gain
energy-yielding nutrients contribute to body fat stores
32
weight & protein
excess amino acids have their nitrogen removeed & are used for energy or converted to glucose or fat
33
weight & fat
fatty acids can be broken down for energy or converted to triglycerides and stores as body fat with great efficiency
34
weight & carbohydrates
excess sugars may be built up to glycogen & stores, used for energy or converted to fat & stored
35
fat cells
increase in size then in number (can increase almost indefinitely)
36
moderate vs rapid weight loss
-with insufficent food, body will draw from energy stores
-exercise & moderate calorie restriction will help body lose fat gradually
-moderate calorie restriction retains more lean tissue than severe fast
37
bodys first response to fasting
-less than a day into fast: liver glycogen stores are used up
-protein is broken down to meet brains need for glucose
38
bodys response to continued fasting
-breakdown of protein to protect cricual organs
-body converts fat into keytone bodies so the NS can adapt to using keytones
39
ketosis
-body takes partially broken down fat fragments & combines hen to form keytones
-after 10 days of fasting, most of the NS energy needs are met by keytone bodies
40
how long can a healthy person live totally deprived of food
6-8 weeks
41
short term fasting
body can handle it but no evidence for cleanse
42
negative effects fasting has on the body
-ketosis upsets acid base balance of blood, promoting mineral loss in urine
-24hrs of fasting causes SI lining to lose integrity
-deprevation leads to overeating
-degrades lean tissue
-decreases metabolic rate
43
ketogenic diet
-low carb, high protein
-large initial weight loss
-rapidly reverses when normal eating resumes
44
why does weight loss occur during keto diet
-water losses
-glycogen losses
limited variety
-protein rich food slow to prepare
-less dessert
45
body's response to low carb diet
-similar to fasting response
-body breaks down fat & protein for energy & ketones for brain
46
DRI reccomendations for carbs
-130g/day RDA
-45-65% TOTAL energy intake from carbs (AMDR)
47
weight loss
-energy in must be less than energy out
-balanced diet safest long term
-increase PA
48
obesity management and weight loss research limitation
-weight loss intervention studies traditionally use BMI classification to define obesity rather than obesity
49
nutrition and weight loss recommendations for adults of all body sizes should:
-be personalized to meet individual values and preferences
-support dietary approach that is safe, effective, nutritionally adequate, culturally acceptable, and affordable
50
setting weight loss goals
-determine if loss or maintanence is most appropriate
-resonable (5-10% loss/year)
-set small goals for diet, PA and behaviour change
51
what to ensure when deciding to change behaviour
-nutrition changes need to be individualized
-realistic caloric intakes
52
caloric restriction
-caloric deficit can result in weight loss in short term but often not sustained
53
common caloric deficit recommendation
500kcal/day less or 3500kcal /week less
54
meal replacements
-shown to reduce body weight, waist circumfrence, BP and glycemic control
55
mediterranean diet
has shown weight loss improvements in glycemic control and blood lipids in people with T2D
56
macronutrient based approaches
no meaningful advantages of one macronutrient distribution over another have reliably been shown
57
balancing carbs, fats & protein
-carbs: 45-56% calorie intake
-fats: 30-35% calorie intake
-protein: 10-35% calorie intake
58
how to chose fats sensibly
-avoid trans fat
-limit saturated fat
-include enough to provide satiety but not oversupply calories
59
portion sizes
-large portions served in restaurants and packages
-ability to judge portion is important
-fat energy is DENSE
-generally at end of meal, same sensation of fullness regardless of portion size
-eating large portions of reduced calorie foods generally not beneficial
60
keeping records
-spot trends & areas of improvement
-measure waist circumfrence
61
alcohol
-strict limit intake
-abundant calories but no nutrients
-reduced inhibitions & sabotage healthy eating
-slows use of body fat & promote central body fat
62
ENergy density
-to lower caloric intake, reduce energy density
-leafy greens have low energy density
-fats high energy density
63
milk & milk products
-higher calcium intake, correlates with less adipose tissue
64
meal spacing
-people who eat small frequent meals are reported to be more successful at weight loss
-mild hunger should promote eating not appetite
-eating regularly before becoming very hungry can help
65
Intensive behaviour therapy/ Intensive lifestyle intervention program
-combine nutrition interventions and physical activity
-show sustained weight loss
-follow ups
-overall benefit
66
physical activity
-should increase if weight loss is a goal
-promotes fat loss, muscle retention, inhibit weight gain
-increase metabolism and reduce appetite
-helps follow diet
-improves BP, insulin resistance, heart & lung fitness
**independent of weight loss
67
Spot reducing
-exercising particular area cannot target fat removal from that area
-aerobic activity promotes release of abdominal fat
-improves strength & tone of muscle in areas
68
3 pillars to support medical nutrition therapy and physical activity
1. Psychological intervention
2. Pharmacotherapy
3. Obesity surgery
69
psychological intervention
-behaviour change
70
surgery
-BMI 30-40 depedning on other factors
-meet criteria
-not always a cure for excess adiposity
-long term complications (vitamin & mineral deficiencies or psychological)
71
Gastric Banding
-provides restrictive method to weight loss
-adjustable silicone band is placed where esophagus and stomach meet
-adjusted with saline
72
Gastric bypass
-reestrictive malabsorptive method to weight loss because stomach and small inestine is reconfigured
-small stomach is created so it only holds a few bites of food
-intestines are cut and entire duodenum and part of jejunum are bypassed
73
Duodenal switch
-restrictive and malabsorptive method to weight loss
-stoamch and SI and reconfigured
-stomach reduction is less than bypass but more of the small intestine is bypassed
74
sleeve gastrectomy (gastric sleeve)
-restrictive approach
-long slender sleeve stapled
-other part of stomach removed
-stomach is banana sized
75
life long nutrition supplements for those with gastric bypass
-multivitamin
-B12
-Calcium citrate
-vitamins D
-Iron
-crushed/chewable/liquid in first 2 months
76
gastric bypass surgery diet
-clear fluids for a day
-full fluids for 10 days
-pureed diet
-4 tbsp per meal
-ensure adequate protein, liquid, vitamin and minerals
77
medications for obesity management
-more infrequent than other medications
-considered early
-not a quick fix
78
what happens if obesity medication stops
weight gain again
79
pharmacotherapy treatment targets
-weight loss
-improve health
-control cravings
-improve quality of life
80
criteria for prescription medication for obesity
BMI >30 or BMI>27 and obesity related complications
81
Sibutramine
-suppresses appetite by inhibiting serotonin uptake
-taken off market in 2010
-max weight loss achieved after 6 months and gained when therapy stopped
82
herbal products for obesity
-effectiveness and safety not proven
-natural does not mean safe
83
Ephedrine/Ephedra
health canada warns against unapproved products sold for:
- weight loss
-increased energy
-body-building
-euphoria
-side effects: stroke/death
84
dieters tea
-herbal laxatives containing senna, aloe, rhubarb root, cascara,castor oil or buckthorn
-cause temporary water loss
-nausea, vomitting, diarrhea, cramping, fainting
85
gimmicks
-steam baths and saunas do not melt fat (dehydrate you & result in water loss)
-brushes, sponges, wraps, creams & massages intended to move, burn or break up cellulite do not result in fat loss
86
key to weight maintence
-accepting it is a lifelong endeavour of healthy habits
-healthy balanced diet and exercise
87
canadas food guide focuses on
nutrition and eating patterns to promote health
88
weight gain
-underweight healthy person should not necessarily try to gain weight., just maintain
-PA to gain muscle & fat; strength training with high calorie diet
-diet alone for weight gain not ideal
-chose high energy dense foods
89
high energy dense foods
-peanut butter in place of lean meat
-avocado in place of cucmber
-olives instead of pickles
90
what should you avoid when trying to gain weight
tobacco - supresses appetite and makes taste buds & olfactory organs less sensitive
