Energy Metabolism And Weight Loss Flashcards
(119 cards)
1
Q
What is the first law of thermodynamics?
A
Energy cannot be created or destroyed, but it can be transformed from a form into an other
2
Q
What is energy balance?
A
Energy intake (+energy stores) - energy expenditure
3
Q
What happens if energy intake and energy expenditure are not equal?
A
- Negative energy balance : utilisation of body’s stores (glycogen, fat, protein)
- Positive energy balance : increase of body energy stores (fat)
4
Q
How is energy consumed in the form of drinks/food stored in the body?
A
- Glycogen in LIVER and MUSCLES
- Fat
5
Q
Where can the body source energy from when in short supply?
A
- Glycogen (liver and muscles)
- Fat
- Protein (last resort)
6
Q
What is the second law of thermodynamics?
A
When energy is transferred/transformed, there is a loss of energy in the form of HEAT
7
Q
What is the second law of thermodynamics’ relevance in terms of energy metabolism?
A
When food is utilised by the body (for chemical, mechanical or electrical work) -> always accompanied by a loss of energy in the form of HEAT
8
Q
What is HEAT in terms of energy metabolism?
A
A byproduct of energy metabolism
Thermal energy that is no longer available for work inside the body
9
Q
What are calories?
A
A unit used to measure the heat-generating potential of food
10
Q
How many calories are in 1 Kilocalorie
A
1000 cal = 1Kcal
11
Q
How many calories in 1g of carbs?
A
4 kcal
12
Q
How many calories in 1g of protein?
A
4 kcal
13
Q
How many calories in 1g of fat?
A
9 kcal
14
Q
How many calories in 1g of alcohol?
A
7 kcal
15
Q
How many calories in 1g of fibre?
A
2 kcal
Yielded form bacterial fermentation in the gut
16
Q
What is the energy currency used to fuel cell processes?
A
Adenosine triphosphate
17
Q
Where does adenosine triphosphate come from?
A
Generated in the mitochondria via the Acetyl CoA formation -> Kerbs cycle -> electron transport chain
18
Q
What are the key nutrients needed to fuel ATP formation within the mitochondria?
A
Magnesium, manganese, iron, sulphur, CoQ10, copper, vitamin B1, B2, B3, B5 and alpha lipoic acid
19
Q
What can damage the mitochondria and interfere with energy production?
A
Nutrient deficiencies, toxins, heavy metals
20
Q
What factors contribute to ATP production and should be addressed in cases of deficiency?
A
- Sufficient nutrient intake (fuel)
- Digestion and absorption
- Respiratory health (oxygen)
- Heart and circulation health (fuel delivery to cells)
- Mitochondrial health
- Thyroid health (up-regulate metabolism)
- Adrenal health
- Healthy detox pathways
- Sleep hygiene (melatonin = antioxidant)
21
Q
What does one’s total energy expenditure depend on?
A
Basal metabolic rate
Physical activity
Thermic effect of food
22
Q
What is BMR?
A
= minimum level of energy required to sustain life -> used to maintain basic physiological functions
Accounts for 60-75% of tot energy expenditure
23
Q
What can impact BMR?
A
Physical activity : exercise can elevate metabolic rate up to 48h and can also increase muscle mass which further elevates BMR
But also stress, caffeine, nicotine, medications, fever, injuries, thyroids hormones,…
24
Q
What is the thyroid gland responsible for?
A
Regulating energy metabolism by secreting hormones that control the metabolic rate of cells
25
How does the thyroid gland regulate the metabolic rate of cells?
Thyroid stimulating hormone (TSH) produced by the anterior pituitary gland triggers the release of thyroxine (T4) and triiodothyronine (T3) from the thyroid
26
What are key cofactors for thyroid health?
Iodine, tyrosine, zinc, selenium, iron
27
How does subclinical hypothyroidism present?
Low energy, reduced appetite, weight gain, feeling cold, dry skin, thinning hair, constipation, irregular periods, depression,….
28
What may subclinical hypothyroidism be caused by?
Nutrient deficiencies (esp. iodine, selenium, zinc, vit. D)
Autoimmunity
Fluoride or mercury
Exposure to endocrine disrupters (e.g. BPA)
29
How can disease/trauma affect an individual’s metabolism?
Infection/fever/injury recovery increase BMR
30
How much can the BMR of a patient with severe burns increase?
More than double
31
How much energy intake do patients with anorexia nervosa need during refeeding?
Up to 2.5 their BMR
32
What is the thermic effect of food?
Aka thermogenesis
The amount of energy required to digest and process the food you eat
33
How much of the total daily energy expenditure is accounted by thermogenesis or TEF?
Approx. 10%
34
What is the thermic effect of fats?
0-3%
35
What is the thermic effect of carbs?
5-10%
36
What is the thermic effect of proteins?
20-30%
37
What are government guidelines for daily energy requirements?
Men : 2500 kcal x day
Women : 2000 kcal x day
38
Why are government guidelines on daily energy requirements inaccurate?
They don’t take into account : body size, muscle mass, current state of metabolic health, sedentary vs active lifestyle
39
What happens when excess CARBS are consumed?
Excessive carbs, esp. refined and in combination with a sedentary lifestyle will force metabolism into DE NOVO LIPOGENESIS (key driver to metabolic syndrome)
Carbs are preferentially used for immediate energy!
40
What is the result of a high intake of fructose?
Fructose is easily converted into fatty acids by the liver : high fructose intake = high DNL
41
What happens to fats consumed in excess of energy requirements?
Stored as adipose tissue
42
When does weight loss happen?
When fewer calories are consumed than the energy requirements and the body is forced to use fat for energy
43
What is the downside of chronic calorie restriction?
May lead to a slowed metabolism -> harder to continue to lose weight
44
How can you make sure that calorie restriction won’t slow down your metabolism?
By eating more nutrient dense food to help re-establish a healthy metabolism
45
Does naturopathic nutrition prioritise in terms of healthy eating?
Food quality over macro composition
46
When can it be necessary to actually track macros?
Working with clients with specific body composition aims, e.g. athletes or weight loss
47
How can you provide personalised macronutrient profiles for clients?
Nutrigenomic testing provides personalised macronutrient profiles based on one’s genes and how well their body metabolises fats and carbs
48
What happens during Ketosis?
When glucose intake is low and glycogen stores decrease -> brain experiences this as stress = cortisol increase = sharp drop in insulin production —> liberates excess fatty acids from adipose tissue -> metabolised to create ketones, used by the brain in the absence of glucose
49
Who stated “a calorie is a calorie” setting up the misconception that fat will always lead to a bigger weight gain compared to other foods?
Wilbur Atwater
50
What happened when the US senate decided to recommend low fat diets?
Biggest rise in obesity and CDV disease in human history
51
What brain region plays a major role in appetite regulation?
The hypothalamus
52
How do gut hormones reach the hypothalamus to modulate digestion and absorption?
From the circulation or via the vagus nerve
53
What other messengers control food intake?
1. Neuropeptide Y
2. Cholecystokinin
3. Insulin
4. Glucagon
5. Glucagon-like peptide 1
6. Bombesin
7. Ghrelin
8. Leptin
54
What is the effect of neuropeptide Y (NPY) on food intake?
INCREASES appetite = potent stimulator of food intake
55
What is the effect of cholecystokinin on food intake?
DECREASES appetite by promoting satiety
56
What is the effect of insulin on food intake?
DECREASE appetite by potentiating the satiating effect of CCK
57
What is the effect of glucagon on food intake?
DECREASES appetite
58
What is the effect of glucagon-like peptide 1 (GLP-1)?
DECREASE appetite (similar action to glucagon)
59
What is the effect of bombesin on food intake?
DECREASE appetite (peptide acting similarly to CCK)
60
What is the effect of ghrelin on food intake?
INCREASE satiety : made by the stomach, increases with food deprivation
61
What is the effect of leptin on food intake?
DECREASE appetite : made by fat cells, promotes satiety
62
What is cholecystokinin
Hormone released in response to food presence in the duodenum
63
What does CCK do?
- Stimulates gallbladder release
- Stimulates pancreas to release pancreatic juice
- Delayis gastric emptying
- Acts on CCK receptors through the CNS and in the satiety centres of the brain stem
64
What types of meal stimulate CCK release the most?
Meals rich in protein and fat over than carb-based meals
65
What stimulates insulin release?
Insulin is released by the pancreas in response to elevated blood glucose
66
What are the 2 main roles of insulin?
1. To lower blood glucose by facilitating its storage predominantly in muscle tissue and liver (glycogen)
2. Responsible for controlling storage/release of fatty acids in/out of adipose tissue —> fat cannot be stored without insulin
67
How does insulin achieve its roles?
1. By regulating several lipase enzymes
2. By activating glucose transport into fat cells via recruitment of glucose-transport protein 4 (GLUT4)
68
What are the 6 metabolic actions of insulin?
1. Stimulate synthesis of triglycerides from free fatty acids
2. Inhibits release of free fatty acids from triglycerides
3. Increases liver synthesis of glycogen (= increase glucose uptake and storage)
4. Inhibits gluconeogenesis
5. Stimulates glucose uptake by skeletal muscles
6. Reduces hunger via hypothalamus
69
How is insulin resistance reached?
Chronic excess energy intake combined with sedentary lifestyle leads the body to produce excessive amounts of insulin
70
Why is central adiposity a typical feature of insulin resistance?
- Increased insulin inhibits Lipolysis
- If there is insulin resistance, Lipolysis is not inhibited = visceral fat deposition
- As visceral fat increases, adiponectin production decreases
71
What is adiponectin?
An adipose-specific protein that increases the oxidation of fatty acids, promotes clearance of excess fat in tissue and improves insulin sensitivity
72
Why is central adiposity problematic?
1. Produces inflammatory cytokines = raise systemic inflammation
2. Visceral fat supplies a constant source of excess free fatty acids as Lipolysis is impaired
3. The excess FFAs pass into blood and liver
73
What is the role of insulin resistance in non-alcoholic fatty liver disease?
Normally, insulin sends 2 singles to the liver
1. Inhibit gluconeogenesis
2. Store the available glucose as glycogen (glyconeogenesis)
In insulin resistance both processes respond poorly to insulin resistance -> risk of chronically elevated glucose levels
74
How does the liver metabolise fructose?
When glycogen stores are full, fructose is converted directly into liver fat
75
What is excessive fructose intake associated with?
NAFLD, obesity, hypertension, excess uric acid, elevated advanced glycation end products (AGEs)
76
What is ghrelin?
An hormone produced by the stomach cells when its empty to stimulate feeding behaviour -> secretion suppressed after meal
77
How are post-prandial levels of ghrelin in obese subjects?
High : their post-prandial suppression is reduced
78
How does weight loss affect ghrelin secretion?
It increases them (hard to keep weight after you lost it!)
79
What has been shown to increase ghrelin concentration?
Dysregulated sleep and elevated cortisol
80
What has been shown to decrease ghrelin concentration?
Exercise
High protein meals (35%) with moderate carbs (45%)
81
What is leptin?
An adipokine produced by white adipose cells in proportion to overall body fat
82
How does leptin work
Increased adiposity = increased leptin = suppressed appetite
83
Why does leptin not prevent obesity?
Obesity promotes a number of inflammatory cellular responses that weaken leptin signalling leading to leptin resistance = failure to suppress appetite
84
What does excess leptin affect?
Affects insulin sensitivity, tissue metabolism, stress responses, reproductive function
All functions mediated by the hypothalamic-pituitary axis
85
What is the end result of leptin resistance?
The metabolic changes caused by leptin resistance produce - Abdominal weight gain (thighs and hips for women, too)
- Chronic fatigue
- Sleep problems
- CDV distress
…
86
Why does leptin resistance risks to become a vicious cycle?
Because additional adipose tissue further contributes to leptin resistance
87
How can you support leptin sensitivity?
- Go gluten free (gluten shown to stop leptin binding to its receptors)
- Reduce sugar consumption (esp. fructose)
- Support gut flora with prebiotics
- Reduce inflammation
- Regular exercise
- Sleep hygiene
88
What is the difference between the gut microflora of an overweight individual vs of a lean individual?
Overweight individuals have reduced bifidobacterium
89
How does what we eat affect which species of bacteria proliferate in the gut?
A high-fat diet increases the levels of gram-negative bacteria and reduces levels of bifidobacteria
90
What is metabolic endotaxoemia?
A persistent, sub-clinical, low grade inflammatory response due to circulation endotoxins (mainly LPS)
91
What condition is metabolic endotaxemia associated with?
Intestinal permeability
92
How do short chain fatty acids support the gut flora?
- Increase secretino of appetite-curbing neuropeptides and peptides (e.g. GLP-2)
- Support the intestinal lining
93
What characterises metabolic endotoxemia?
1. Enhanced lipopolysaccharide (LPS) absorption
2. Low grade chronic inflammation
3. Insulin resistance
94
What are lipopolysaccharides?
A component of the outer membranes of gram-negative bacteria and reduces
95
Why is the modification of gut flora with prebiotics an important part of an effective weight management and metabolic health protocol
- Promote satiety
- Reduce hunger
- Reduce food ingestion
- Suppress ghrelin
- Increase peptide YY and GLP-1
96
Why have probiotics been shown to be important in supporting metabolic syndrome
- 1 trial found that diet + lactobacilli and bifidobacteria was significantly more effective at reducing blood glucose level and increasing insulin sensitivity compared to dietary measures
- 1 trial found 4 weeks of probiotic supplementation preserved insulin sensitivity (decreased in placebo group)
97
What is appetite?
A psychological reaction that stimulates a physiological response such as salivation
98
What is hunger?
A physical reaction that includes chemical changes in the body from a prolonged period without eating
99
Why do foods with high fat/sugar content stimulate our dopamine reward system?
To hunter-gatherers, these foods offered survival advantage
100
Why do obese people get less of a reward response form palatable foods?
They have less dopamine receptors in the brain
More repeated intake of palatable foods = down regulation of dopamine receptors
101
What cultural/social factors affect food intake?
- Religious traditions
- Celebrations
- Meal pattern
- Family traditions
- Work lunches/dinners
- Education
102
What sensory factors influence food intake?
- Appearance/smell
- Taste and palatability
- Addiction
- Packaging and advertising
- Surrounding and ambience
- Learned likes and dislikes
- Flavour fatigue
103
What emotional factors affect food intake?
- Comfort eating
- Stress
- Insomnia
- Loneliness
- Sadness
104
What other factors influence food intake?
- Hormones
- Disease states
- Climate
- Medications
- Distractions
- Value for money/cost
105
Why is keeping blood sugar even a good strategy to regulate food intake?
Studies show that sharp spikes in blood sugar lead to drops which increase activity in the NUCLEUS ACCUMBENS = area of the brain that produces desire to eat
106
How can you maintain a stable blood sugar?
- Include protein with every meal
- Avoid refined carbs/sugar and include complex carbs
- Chew well, eat mindfully, don’t overeat
107
How can you keep track of food intake to support regulation?
- Be clear on portion sizes
- Monitor changes in weight, body fat and waist circumference
- Food diaries can help to regulate food intake
Keep track of what we eat = more conscious food choices
108
What is mindful eating?
Process of paying attention to your eating experience without judgement to help you become aware of the reasons behind your hunger
109
What does it mean to focus on “adding in” rather than “taking out”?
By adding in more nutrient dense foods (high in fibre, water, phytonutrients, …) we displace energy dense foods that have high amounts of fat, sugar and starch and less water, fibre and micronutrients
110
What hinders weight loss?
- Over-eating and junk food
- Sedentary lifestyle
- High blood sugar
- Chronic stress (cortisol = high blood sugar)
- Poor sleep
- Underactive thyroid
- Gut flora imbalances
111
How can you help a client reducing stress to support weight management?
1. Identify + address root cause of stress
2. Diaphragmatic breathing exercises x vagus nerve stimulation
3. Eat to balance blood sugar
4. Use adaptogenic/nervine herbs
5. Reduce stimulants and alcohol
6. Eat a diet high in magnesium, Bs and C
112
How can you help a client with their sleep hygiene to support weight management?
1. Avoid coffee and alcohol
2. Plan 8.5/9 h in bed (lights out before 11)
3. Endure dark, cool, well ventilated bedroom
4. 1-2 h before bed minimise exposure to bright lights/screens
5. 3h before bed finish eating and aerobic exercise
6. Aim to go to sleep and wake up at the same day each day
113
How can alternate fasting help a client with weight management?
By alternating between periods of normal eating and periods of fasting/caloric restriction (e.g. normal eating 5 days x week and reducing calories to 600 2 days x week) = reduced fat mass (esp. trunk), LDL cholesterol and triglycerides
114
Hoe can time restricted feeding help a client with weight management?
By limiting all of one’s eating to a certain number of hours per day, studies demonstrate : weight loss and reduced caloric intake without counting calories + reduced cardiometabolic risk factors (blood pressure, fatty liver, LDL, insulin resistance)
115
How can a ketogenic diet help clients with weight management?
High fat / moderate protein / very low carb diet
=
- Lack of glucose induces body to burn ketones and fats for energy
- Health benefits : reduced body fat, lower inflammatory and oxidative burden
Therapeutic uses : T2DM, CDV disease, cancer, Alzheimer’s, Parkinson, PCOS, epilepsy,…
116
How can HIIT help your clients with weight management?
Short bursts of intensive exercise alternated with low intensity recovery
=
Creates an oxygen debt which is repaid via EPOC (excess post exercise oxygen consumption)
=
Increase metabolic rate, lowers body fat, fasting blood glucose, blood pressure and resting heart rate
117
What is the best diet for weight loss?
There isn’t one : we are all unique, biochemical, psychological, constitutional and emotional beings and what works for a person will not necessarily work for another
118
What factors are there to evaluate when composing a plan for a client?
1. Does the plan address behavioural triggers of eating?
2. Does the plan provide all necessary micros and macros?
3. Is it a diet or a lifestyle change?
4. What is the motivation?
5. Does the plan offer education and support?
6. Does the plan include exercise?
119
What are the basics of naturopathic nutrition?
Whole, organic, seasonal food
Follow food combining principles
Fit with one’s constitution
Free of ultra processed foods
Chew each bite well
Avoid drinking with meals
3 meals x day max
