Obesity Flashcards
Midterm 2
Four M’s
Mental
Mechanical
Metabolic
Monetary
T2DM Definition
May range from predominant insulin resistance deficiency to a predominant secretory defect with insulin resistance
Sedentary lifestyle
Obesity
usually occurs >25 years of age
>90% at least overweight
A1C
Proportion of hemoglobin with glucose attached to it
Reflects average blood glucose over last 2-3 months
People with diabetes will have a measure of ≥6.5% (in adults)
Risk factors of T2DM
Obesity (modifiable)
Low PA (modifiable)
Aging (non-modifiable)
Genetics (non-modifiable)
Increased FFA effect on Muscle
Increases Insulin Resistance
Decreases Insulin sensitivity
Decreases glucose uptake from circulation
Decreases oxidative potential
Increased FFA effect on Liver
Stores more fat in liver (contributes to fatty liver disease)
Increases Gluconeogenesis
- Makes glucose, releases it into circulation
Dyslipoproteinemia
- decreases HDL-C
- Increases VLDL- Tg
- Increases Dense LDL
Effect of Increased FFA on pancreas
Hyperinsulinemia
- Causes increased insulin release from pancreas
- leads to eventual B-cell failure
– Hyperstimulation all the time leads to failure
Hypertension
140/90
Very responsive to weight loss and salt restriction
16% of the population has hypertension
High Normal blood pressure
130/80
Pre-Diabetes
Primary Hypertension
High blood pressure with no obvious underlying cause –> Aging
Secondary Hypertension
Caused by other conditions affecting the kidneys, arteries or diseases
Adiponectin
Secreted by fat cells
More adiponectin means more insulin sensitivity and vice versa
Less Adiponectin also causes an increase in vasoconstriction
Secreted exclusively by adipocytes
Inversely proportional to %body fat (more likely adipocyte size)
Weight (fat) loss, increased adiponectin concentrations
Cholesterol Ester Transfer Protein (CETP)
Released via the adipocytes
Transfers cholesterol from HDL to LDL
LDL loses some of its trigylcerides
- causes LDL particles to become more dense (VLDL)
Apo B
Main protein that makes VLDL and LDL
Elevated levels of Apo B are associated with an increased risk of cardiovascular disease.
- Each LDL particle contains one Apo B, measuring Apo B can provide a more accurate assessment of cardiovascular risk compared to measuring LDL alone
Factors that determine Metabolic Syndrome
WC (visceral adiposity)
Elevated triglycerides
Reduced HDL-C
Elevated BP
Elevated Fasting plasma Glucose
Need to meet ≥3 measures to have metabolic syndrome
Osteoarthritis and Obesity
Obesity in the number one preventable risk factor
- losing weight can reduce the likelihood of getting osteoarthritis
Splanchnic Adipose Tissue
Visceral Adiposity, Intra-abdominal
When released, visceral fat drains directly to the liver, and is a major contributor to metabolic syndrome
Comparison of FFA release when insulin is low vs when insulin is high (after a meal)
When low
- Very small percentage of FFA is released from splanchnic
When High
- Half the FFA is coming from splanchnic area
Gender differences in VAT
Men are at greater risk than women of greater VAT and cluster of metabolic conditions
25% of all men are affected
On average, MEN have 2x the VAT as pre-menopausal women
Gender differences in VAT following menopause in women
Men and Women with matched VAT have similar CVD risk profiles
Post-menopausal women accelerated accumulation of VAT
Potential treatment with HRT or other therapies
Ectopic Fat
Fat accumulation on an organ
Weight loss surgery Qualifications
BMI ≥40 - independent of the presence of obesity-related complications
BMI 35-40 - who have at least one major obesity related complication
BMI 30-34.9 - who have been refractory to non-surgical attempts at weight loss with obesity-related complications, Especially T2DM
Contraindications of Weight Loss surgery
Medical Conditions making surgery at “high risk”
Pregnancy
Genetic Conditions
Certain mental health disorders
Substance abuse / alcohol abuse
Poor attendance + refusal to make lifestyle changes
Unable to comprehend advice
Adjustable Gastric Banding (AGB)
Performed laparoscopically
Works by restricting amount of food that can comfortably be eaten by implanting an adjustable band around the opening of the stomach
Simple and relatvely safe
short recovery period
NO ALTERING OF ANATOMY OR PHYSIOLOGY
Slower initial weight loss
Often weight loss may be less pronounced than other surgeries
Less improvement of diabetes than with bypass
REVERSIBLE
RESTRICTIVE
NO MALABSORPTION
Weight loss of about 20%
Sleeve Gastrectomy (SG)
Removes large portion of the stomach and staples it closed so the volume is greatly reduced
No insertion of foreign objects
Reduces food intake (removes ghrelin cell mass: lower hunger)
Low potential for leakage
Reduced Ghrelin and potential increase in GLP-1
RESTRICTIVE
NO MALABSORPTION
NOT REVERSIBLE
Average Weight loss of just under 30%
Roux-en-Y Gastric Bypass
Changes passage of food so that a large amount of food is not absorbed in the beginning of the small intestine by bypassing it and connecting to a later part of the SI.
Greatly controls food intake
Reversible in an emergency - though this procedure should be though of as permanent
Minimal Diet restriction
Slightly better weight loss maintenance or reversal of T2DM compared to SG
Vomiting if food is not chewed or eaten too quickly
Staple line failure or ulcers
Risk of deficiencies in vitamins (B12), iron and Calcium
RESTRICTIVE
MALABSORPTIVE
NON REVERSIBLE
Average weight loss of just OVER 30%
Duodenal Switch
Combines the SG with significant intestinal bypass
Best reversal of T2DM
Partially reversible in an emergency - though should be thought of as permanent
Staple line failure or Ulcers
Risk of deficiencies in vitamins (B12), iron and calcium
RESTRICTIVE
MALABSORPTIVE
NON-REVERSIBLE
Average weight loss of just over 40%
Metabolic Surgeries
Duodenal Switch and Roux-en-Y Gastric Bypass
Lead to improved appetite/metabolic hormones like GLP-1 and PYY (food introduced to distal intestine)
- Gets to distal SI quicker so GLP-1 and PYY is released more rapidly, reducing appetite
Dumping Syndrome
Sugary food leaves the stomach quickly
Intestine swells causing cramping and pain
Symptoms: Fast HR, Sweating, Nausea, diarrhea or vomiting
Can be caused by any of the surgeries that lower the size of the stomach
Orlistat
Brand Name = Xenical
Lipase inhibitor
- stops your intestine from breaking down triglycerides in food so you don’t absorb fatty acids
30% of the fat you consume will not be absorbed
- fat ends up in the feces
- interaction between the body’s natural high coefficient of digestibility of fat via the drug
Orlistat (xenical) needs a low fat diet otherwise side effects of the drug would be too great
- reason why orlistat (xenical) placebo will also lose weight
Long term adherence (1-year after) is low (30%)
Side Effects
- Oily Stools (more fat in stools)
- Anal leakage
- Gas with discharge
- Urgent bowel movements
- Diarrhea
- Cramping or pain
- Reduced absorption of vitamins
AVERAGE WIGHT LOSS 10% vs 6% placebo
Liraglutide
Brand Names = Victoza and Saxenda
GLP-1 Receptor Agonists
- causes weight loss by slowing gastric emptying, effect on satiety (brain)… not causing hypoglycemia
Side effects
- Gastrointestinal side effects
- nausea
- vomiting
- pancreatitis
AVERAGE WEIGHT LOSS = 8.6% vs 2.6% placebo
Semaglutide
Brand Names = Ozempic (injection), Rybelsus (oral), Wegovy
GLP-1 Receptor agonists
- slows down gastric emptying lowers hypoglycemia
Different from Liraglutide that it is a once weekly injection, rather than daily oral medication.
Side Effects
- MAIN, gastrointestinal issues
- Nausea
- vomiting
- pancreatitis
AVERAGE WEIGHT LOSS = 15% vs 2.4% placebo
Naltrexone-Bupropion
Brand Name = Contrave
Just Naltrexone BN = ReVia (opiod agonist)
Just Bupropiod BN - Wellbutrin (Antidepressant)
Naltrexone:
- used for treatment for alcohol or opiod dependence
Bupropion:
- reduces uptake of norepinephrine and dopamine
Either alone does not cause weight loss, but together, weight loss of ~5kg more than placebo
Mechanism seems related to reductions in food cravings
Side Effects:
- birth defects
- headaches
- dry mouth
- dizziness
AVERAGE WEIGHT LOSS = 6.1% vs 1.3% placebo
“Diet”
Sum of food and drink an individual habitually consumes
Low Fat Diet; what are they
<30% of EI from Fat (some say 10-15%)
Maybe
- <10% EI from saturated Fat
- NO trans fats
Can be “ad libidum” or with concomitant emphasis on energy restriction
Looking at just reducing fat or looking to reduce EI all together
Why Would a low fat diet work
Many high fat foods are very energy dense (less volume, high calories)
- if you can eat foods with lower calorie content, you can consume till you feel full, while still lowering EI
Body is very effective at turning food fat into body fat. Eating non-high fat foods will reduce the effectiveness of turning foods into body fat
Why Would a low-fat diet not work
Palatability
- low fat food often doesn’t taste as good. Won’t eat as much and may not adhere for long term
Potential High CHO/Sugar Content
- If replacing high-fat with processed sugar foods, you’re not going to get ideal goal of low fat dieting
Low Carb Diets; What are they
Reduced Carb Diet: <130g of carbs per day, up to 45% of total calories
Low carb diet: 30-130gg of carbs per day
Very low carb diet: <30g of carbs/day; will usually permit ketosis to occur
Ad libidum intake of fat and animal protein
Why would a low-carb diet work
Body promotes adipose tissue metabolism when CHO absent
- **need to store CHO for the brain
Rapid weight loss due to:
- Appetite suppression. Protein and fats effect on CCK, GLP-1
Water loss (1-2kg in 1-2 weeks)
- Glycogen reserves go down on a low carb diet if your exercising
- Every gram of Carb stored in the muscle/liver, stores about 3g of water
Why would low-carb diets not work
Too restrictive
Unlikely to be adhered long term
Concerns with high meat consumption
Can be discouraging after initial success slows down
Potential for nutritional inadequacies
Low-Carb vs Low-Fat
At 6 months:
- Low Carb has 3.3kg greater weight loss than Low fat
- low CHO better for HDL and TG
- Sometimes better for blood glucose, blood pressure lowering (indicators of metabolic syndrome)
- Low fat better for LDL and total cholesterol levels
– some low carb diets increase LDL
12 months:
- Similar body weight
- Body composition was better in low fat diets
- Low carb had greater improvement in HDL at 2 years
High Protein Diet; what are they
Not consistently Defined, often hard to distinguish from low carb diet
Relative terms
- >25% of kcal from protein
- >1.2g of protein / kg of BW
Why would high protein diet work
High satiety
Very energy demanding to store excess
- Excess protein can be difficult to store due to low transferability of protein to amino acids
Restrictive
Can taste good
Preserve FFM
Why would High protein diet not work
Concerns with high meat consumption
- Health perspective
- Potentially costly
Implications for High protein diet
Evidence shows may help in prevention of regaining weight after weight loss intervention
High protein - low glycemic index diet was only diet in study shown to stop regaining weight
Very Low Calorie Diet: what are they
<800 kcal or <50% of RMR
(<900 kcal according to health canada)
Why would VLCD work
Simple to follow
- No food prep
- No calorie counting
Large energy defecit
Rapid weight loss can be motivating
Could be a starting point to other changes
Help break eating habits of “addictions”
Why Would VLCD not work
Not a long term solution
No changes in behaviours… once VLCD is finished people simply return to old behaviours (Opra)
Very Very costly
~3000-3500 US per treatment plan (12 weeks)
Must be medically supervised
Negative Side effects of VLCD
Gallstones (up to 25% of patients)
Old intolerance, hair loss, headache, fatigue, dizziness, volume depletion, muscle cramps, constipation
VLCD’s deaths occurred in the 1970s when dieters consumed products that contained low-quality protein and were deficient in vitamins and minerals
Recommendation 1 from Norm’s PA in Obesity management
Aerobic PA (30-60 minutes o f moderate to vigorous intensity most days of the week) can be considered for adults who want to:
- achieve small amounts of body weight and fat loss
- achieve reductions in abdominal visceral fat and ectopic fat such as liver and heart fat, even in the absence of weight loss
- favour weight maintenance after weight loss
- favour the maintenance of FFM during weight loss
- Increase cardiorespiratory fitness
Recommendation 2 from Norm’s PA in Obesity Management
For Adults living with overweight or obesity, resistance training may promote weight maintenance or modest increases in muscle mass or FFM and mobility
Recommendation 3 from Norm’s PA in Obesity Management
Increasing exercise intensity, including high-intensity interval training, can achieve greater increases in cardiorespiratory fitness and reduce the amount of time required to achieve similar benefits as from moderate-intensity aerobic work
Recommendation 4 from Norm’s PA in Obesity Management
Regular PA, with and without weight loss, can improve many cardiometabolic risk factors in adults who have overweight or obesity, including:
- hyperglycemia and insulin sensitivity
- High blood pressure
- Dyslipidemia
Recommendation 5 from Norm’s PA in Obesity Management
Regular PA can improve health-related QOL, mood disorders and body image in adults with overweight or obesity
Physical Activity and Body Comp
Obesity management interventions that incorporate exercise generally report either maintenance or gain in FFM
Exercise alone is effective in reducing abdominal visceral fat
Interventions that include diet and exercise have the most benefit. Reducing the most fat mass and preserving FFM than diet alone.
Intensity Considerations
While greater intensity requires less time to complete a given volume and leads to greater improvements in cardiorespiratory fitness. It is not associated with statistically significant greater reductions in weight or fat mass
Implications of Working At Fat-max
This where the absolute most fat is being oxidized, as the muscle triglycerides are being called on more. 55-65%
- However, No evidence that exercising at fat-max increases fat loss compared to working at higher intensity
Greater RELATIVE fat oxidization occurs at 25% of maximum oxygen uptake
- higher percentage of cal/kg/min is coming from fat, but less absolute kcal being burned
Resistance Training For Weight Loss
Not very effective
- BUT can contribute to change in body comp (retain FFM)
Improved metabolism
Maintenance of Function
STRONGEST PREDICTOR OF IF SOMEONE WILL DIE IS LEVEL OF FITNESS
<5 MET fitness level is high predictor of different mortalities
