Assessment of Popular Diets Flashcards
(97 cards)
1
Q
Weight loss diets: Nutritionally balanced diet calories ___
A
> 1200 kcal
2
Q
Weight loss diets: Nutritional unbalanced calories ___
A
800-1200 kcal
3
Q
Weight loss nutritionally unbalanced diets typically refer to ___
A
Imbalance in one or more macronutrient
- HFLC
- LCHF
4
Q
What are the 4 characteristics of weight-loss diets?
A
- Nutritionally balanced
- Nutritionally imbalanced
- Calorically dilute
- Fasting/Semi-fasting
5
Q
What kind of diets can be nutritionally balanced?
A
- Unrestricted kcals
- Restricted calories, but varied items
- Formula based
6
Q
What is the description and characteristic of an unrestricted kcal, nutritionally balanced diet?
A
- liquid homogenate
- monotonous
7
Q
What is the description and characteristic of restricted kcal, varied item nutritionally balanced diet?
A
- Mixed low cal diet (1200 kcal)
- Carefully controlled caloric intake but palatable
8
Q
What is the description and characteristic of formula-based nutritionally balanced diet?
A
- Liquid homogenate
- Carefully controlled caloric intake, monotonous
9
Q
What are the 2 types of nutritionally unbalanced diets?
A
- Altered proportion of micronutrients (HCLF, LCHF)
- Specific food item focused
10
Q
What are the characteristics of a LFHC diet?
A
- reduced efficiency of calorie utilization
- reduced fat deposition
- difficult to compensate for excluded food
11
Q
What are the characteristics of a LCHF diet?
A
- ketosis
- decreased appetite?
- small excretory loss of calories
- difficult to compensate for excluded foods.
12
Q
What are characteristics of specific food item focus?
A
Very reduced calorie intake, monotonous
13
Q
What is an example of a calorically dilute diet?
A
High fibre, low fat
14
Q
What are characteristics of calorically dilute diet?
A
Slowed ingestions rate (more chewing required), impaired digestion/absorption of nutrients, satiety-inducing
15
Q
What are 3 examples of fasting diets?
A
- Very low calorie diets
- Protein sparing modified fast
- Total fasting
16
Q
Which fasting diet is highly ketogenic?
A
Total fasting
17
Q
Which fasting diet may reduce body fat, spare protein and are 600-800 kcal/day?
A
Very low calorie diets
18
Q
Give examples of HFLC diets
A
- Carb Addict’s
- Protein Power
- Atkins
19
Q
Give examples of moderate fat (balanced) diets
A
- Weight watchers
- Volumetrics
20
Q
Give examples of low and very-low fat diets
A
- Ornish (Eat more, weigh less)
- Pritikin principle
21
Q
Give an example of a food combining diet
A
Montignac
22
Q
What are some red-flags of fad diets?
A
- Losing more than 1 kg/week without cutting calories or increasing PA
- Losing a lot of weight while eating a lot of high-calorie foods
23
Q
Is permanent weight loss a red flag?
A
Yes
24
Q
Is rapid loss of >1-2 weeks over 4 weeks realistic?
A
NO, and is a red flag of fad diets. Recall that we can lose weight quite rapidly (due to glycogen stores) within one week, but after that it is extremely unlikely
25
What is a simple red flag of a fad diet?
That it is suitable for ANYONE to use
26
What are some issues to consider when assessing a weight loss plan?
1) Nutritional adequancy
2) Based on food groups/DRI
3) Weight loss for all?
4) Do they comply with healthy guideline to reduce chronic disease?
27
A diet that excluded one or more food groups is likely to what?
Create a deficit and cause weight loss. BUT may be nutritionally inadequate
28
Describe the philosaphy/rationale behind the HFLC diets
By decreasing the amount of carbs in the body, we will suppress insulin signalling, which is beneficial as high insulin levels lead to insulin resistance and the deadly diseases of insulin. If we create an environment where glucagon in predominant, we will promote lipolysis and burn fat.
29
What would you counter to the claim surrounding HCLF diets?
While it is true that decreasing carbs decreases insulin secretion - this is not the entire story, In healthy individuals, they keep their insulin levels and glucose levels tightly regulated regardless of the amount of carbs they consume. Furthermore, decreasing the proportion of one macronutrient is likely to create an energy deficit - therefore leading to weight loss
30
Weight loss is related to the excess consumption of ____ and not high insulin signalling
energy
31
Low carbohydrates =
<60 g/day intake
32
What is the timeline of low carbohydrate diets?
1864 - now
33
Who was the first to discover the HFLC diet?
Dr. Banting - who discovered insulin and noticed that when obese or diabetic people fasted (and a fasted state mimics a very low carb diet)they were "better" off and tied this to a decrease in insulin circulation.
34
What are the principles of the atkins diet?
Originally called for 60-65% fat and less than 20 g of CHO. Now Atkins20 is done in 4 phases, increases carboydrates by ~25 g at each phase, and slowly incorporating grains, fruits and veggies.
35
What is the range of carbohydrate intake on the atkins diet? How many kcal would this correspond to?
20-100 g, which corresponds to 80-400 kcal of carbohydrates.
36
Whats the brains requirement for glucose?
120 g/day, which is about 480kcal
37
What are the potential harms of the atkins diet?
- High in sat fat, CVD risk NOT known
| - Low in fibre, B vitamins
38
What are the potential benefits of the atkins diet?
- Low in added sugars
- May improve diet quality
- Reduced calories in most
- Reduced serum TGs
39
What are ketogenic diets/ What were the originally used for?
Classically, a therapeutic diet used to treat epilepsy and seizures when they could not take medication - 90% fat.
40
How can we consume 60% fat and achieve the same state of ketosis as consuming 90% fat?
If we ensure some of our fat comes from MCT oil, we can consume 60%
41
What is the classic ration of ketogenic diets for Fat:CHO:protein?
4:1:1
42
What is the rationale for the keto diet and weight loss?
Low insulin levels will remove suppression of lipolyiss, burning fat.
Suppression of appetite based on high production of ketone bodies (?)
43
CHO AMDR keto
6-12% CHO
44
Fat AMDR keto
60-70%
45
Protein AMDR keto
20-30%
46
Why would we want to reduce protein on keto?
Some of them are insulinogenic
47
How many g of CHO to induce ketosis?
50 g of CHO or less
48
If we suppress lipolysis we will suppress _____. Lipolysis is suppressed by ____
ketogenesis
| insuline
49
Insulin will inhibit ____
glucahon
50
In high rates of lipolysis, we produce large amount of ____
glycerol and FFA
51
In ketosis, how is some glucose still produced and used by RBCs, renal medulla, brain?
Recall that glycerol from high amounts of lipolysis will feed into gluconeogenesis in the liver, producing glucose.
52
How is the brain fueed in ketosis?
Glucose AND ketone bodies (predominately ketones in long-term adherence to keto diet/starvation)
53
Describe why there is a quicker weight loss in HFLC diets vs LFHC
Depletion of glycogen, but will eventually will even out to the same weight loss (+/- 1 kg) as LFHC
54
Why is there a decrease in glucose in HFLC diets? Slight decrease in LFHC diets?
1) Less carbs consumed, less glucose and most in bloodstream is produced via gluconeogenesis
2) Since it is a weight reduction diets, lower glucose due to energy restriction
55
Why does serum insulin decrease and glucagon increase in LCHF diet?
Less insulin signalling due to decrease intake of carbs and protein
56
Why are plasma FFA higher in HFLC diets? Why is there still some increase seen in LFHC diets?
1) Increased lipolysis due to decreased insulin
| 2) Energy deficit, therefore still some lipolysis
57
Why do serum TGs decrease more in HFLC diet?
Less carbohydrates consumed, less converted into TGs after glycogen storage full
58
Why are serum uric acids greater in HFLC diet?
If ketones are greater, so will uric acide
59
The rapid weight loss when following a HFLC diet is explained by what?
The depletion of glycogen stores and loss of water weight
60
When entering a weight maintenance period - will those who had lost weight on a HCLF or HFLC diet regain quicker?
HFLC, as there glycogen stores and water weight will be replenished
61
In overall weight loss, when the HCLF and HFLC groups underwent a weight loss and weight maintenance period - which group lost the most weight?
HFLC lost ~1kg more, but is not clinically relevant. Eventually, they both lost the same amount of weight as they were isocaloric
62
Upon following a completely fasted diet, 800 kcal keto diet and 800kcal mixed diet - which lost the most weight?
Fasting > 800kcal keto > 800kcal mixed
63
After increasing calories to 1200kcal BUT following the same diets (except for fasting) what happened?
- Post fasting had the MOST weight regain
- Post-keto had some weight gain
- Post mixed CONTINUED WEIGHT LOSS
64
What dies promotes weight loss and prevents weight gain?
Mixed diets
65
Fasting results in lots of ___
protein loss
66
More water loss in ___ than mixed, but less than total fasting
ketogenic diets
67
Fat loss is relatively the same between keto and mixed diets - what explains this?
They were both energy restrictive diets, therefore encouraging lipolysis
68
In a systematic review looking at 13 RCTS, what was the reported weight loss amongst participants on the keto diet vs a low-fat diet after 12 and 24 months?
Only a difference of 0.9 kg less in keto
69
In a systematic review looking at 11 RCTs, what was the weight loss reported amongst individuals following a keto diet vs low-fat diet at 6 and 24 months?
Only a difference of 2.2 kg less in keto
70
In a recent RCT following 609 people , what was the weight loss found for those following the keto diet vs those following the low-fat diet?
Keto diet: -6kg
Low-fat: -5.3 kg
The difference is VERY minimal, as we know that any kind of energy restriction will induce weight loss - regardless of macronutrient compostion
71
After explaining to someone that the keto diet will result in the same weight loss as an isocaloric low-fat diet, they claim that the keto diet will also suppress their appetite, therefore increasing weight loss. How could you show them that this is NOT true?
In the Direct Trial study, low fat and keto diets resulted in the same increase in intake after being on a hypocaloric diet. If ketones suppressed appetite, we would see a smaller increase in intake - this is strong evidence that the keto diet can suppress appetite.
72
In addition to no effect on weight loss, keto diets also have no effect on ___
Genotype
| Baseline insulin secretion
73
What are some common side effects of the keto diet?
-constipation
-halitosis
-muscle cramps
-headache
-diarrhea
-weakness
0raks
74
What are some less common side effects of keto diet?
- Irritability due to hormonal changes
- Carnitine deficiency
- Elevated serum LDL
- Water soluble vitamin deficiency
- Renal stones
75
Should children be put on the keto diet?
NO becuause it is associated with growth inhibition
76
Explain the difference between acidosis and ketoisis
In a healthy individual, we will NOT reach dangerous ketoacidiosis, as our renal function is normal.
77
When could a keto dit become dangerous?
During illness, compromised renal function or dehydration
78
Why would dehydration be dangerous on a keto diet?
Because we need a sufficient amount of water and electrolytes to excrete keto acids
79
Keto diet is low in grains, which is low in B vitamins (thiamine) - what could this cause?
Optic neuropathy
80
What is the rationale behind the LFHC diet (Ornish, pritikin principle)
-Stems from the "lifestyle heart trial" where CHD can be reversed through lifestyle changes, and weight loss is a secondary effect
81
In LFHC diet, calories are considered ___
NOT equal
82
Based on the ornish diet, what are the 3 categories of foods?
Food to eat in :
- Unlimited quantities
- In moderation
- Completely avoud
83
In ornish, what food to eat in unlimited quantities?
-Bean, legumes, grains, fruits and vegetables
84
In ornish, what foods to eat in moderation?
Non-fat dairy, non-fat/ very-low fat commercial products (<2 g fat/serving)
85
In ornish, what foods to avoid completely
-All meats, oils, avocados, nuts, seeds, olives, simple sugar, alcohol
86
Is ornish diet a vegan diet?
NO - low fat milk products are permitted
87
What are the potential harms of a LFHC diet?
- Low in liposoluble vitamins
- May be high in sugar
- Potential for gaining weight (~1800kcal)
88
What are the potential benefits of the ornish diet?
- May improve diet quality
- Reduced calories
- Improved lipid profile and CVD risk (decreased FFAs in circulation)
89
What does the ornish and keto diet have in common
- May improve diet quality
| - Reduced calories
90
Volumetrics is based on ___
energy density, where you have largest protionsof the lowest energy dense foods
91
Montignac diet is based off ___
limiting high GI foods as they spike insulin levels
92
CVD risk is ___ with high fat diets, but we know that low-fat diets reduce CVD risk
Unknown
93
What are some adverse effects to extreme dieting?
- Gallstone formation
- Osteoporosis
- Weight cycling
94
What are the impacts of weight cycling?
- favours weight regain
- Negative impact on eating behaviour/eating disorders
- Impact self-esteem
95
What are absolute contraindictions to VLCD?
- Malignant arryhthmias, unstable angine
- Protein wasting disease, or drug causing protein wasting
- Major system failure
- Body weight at BMI <27
- Pregnancy or lactation
96
When is it relatively inadvisable to follow VLCD?
- Congestive heat failure
- Diuretics, adrenergic stimulating agents
- History of failing to comply to medical regimes
- Body weight at BMI <30
- Substance abuse
97
When should someone follow a VLC D with caution?
- Angina or history of heart disease
- Presence of systemic disease
- History of psychiatric or emotional disorder
- Chronic drug therapy (insulin, anti-inflammatory agents)
