Week 6: Obesity Flashcards
Strengths and limitations of BMI
Benefits
- Provides a good indication for risk of metabolic health
- Quick and easy to calculate
Limitations
- Does not consider body composition (e.g. muscle fat or bone)
- Specific ethnic guidlness have not been well established
- Spinal deformities (e.g. kyphosis) - the individual may appear to be shorter and thus increasing their BMI
HEALTHY BMI IS NOT THE GOAL FOR EVERYONE!!!
Slide 11 of Week 6
Global prevalence of Overweight and Obese individuals
Overweight
39% of adults
Obese
13% of the adult population (11% male and 15% female)
Slide 20 of Week 6
Incidence and Prevalence of Overweight and Obese in Australia
In 2022 1 in 3 adults were overweight
3 in 10 were obese
increasing number due to the change being driven by the increase in proportion of adults categorised as obese
Slide 23 of Week 6
Groups at higher rate of Obesity
- Males more likely to be overweight or obese compared to females
- Higher rates in remote areas
- Boys have higher % than girls
TLDR –> Low SES, Men, ATSI, Remote
Slides 24-28 of Week 6
Defining obesity with Waist circumference
WC - a method used to measure obesity and overweight
Wider waist - associated with ↑ risk of metabolic complications
↑ risk
Men: ≥ 94cm
Female: ≥80cm
Substantially ↑
Male: ≥ 102cm
Female: ≥88cm
Slide 33 of Week 6
2 components that make up weight homeostasis
EI & EE
Energy Intake (EI)
The energy we get from macronutrients in food or drinks
Energy Expenditure
Has 3 components:
1. Basal Metabolic Rate (BMR)
- Energy used at rest
- Main predictor is lean mass
- ~50-80% of EE
2. Phyiscal Activity
- Energy used for movement
- Approx 20% of EE
3. Theromogensis
- Used for digestion
- 5-10% of total EE
Slide 42 of Week 6
How does our body maintain body weight?
1. Using apetite hormones
- Gaining weight: Promote fullness (leptin)
- Losing weight: Increased ghrelin secretion to make you feel hungry
–> Also reduction in BMR to conserve energy to minimise further weight loss
2. Adjust energy expenditure (MAKES SENSE)
3. Gut Microbiota
- Microbes in intestines influence how we metabolise and store energy
- Leaner people tend to have a more diverse microbiome and thus impacts on fat storage
Slide 43 & 44 of Week 6
What are the 7 factors affecting weight regulation?
- Dietary
- Hedonistic (pleasure of eating)
- Sleep - Deprivation
- Genetics (fto gene)
- Psychosocial
- emotional eating, food reward etc - Environmental
- Availability of foods (access)
- Non condusive to regular PA - Political Factors
- Food taxation
- Advertising
Slide 54 - 55 of Week 6
What is the Pathophysiology of obesity
Pathophysiology = the disordered physiology underlying disease
Simple obesity
- The vast majority of cases
- Results from excess energy intake and minimal EE
Genetic Disoders
- Prader willi syndrome
- Causes extreme appetite
- 70% of cases is from fathers chromosome 15 bein deleted
- 25% = 2 copies of chromosome 15 from mother
- Distrupts the normal functioning of the hypothalamus
Endocrine Disorders
- Cushings syndrome
- Hypothyroidoisim
- Insulinoma
- Polycystic Ovarian Disease
Slide 57 of Week 6
Why is obesity unhealthy?
Obesity induces fat cell hypertrophy
- Large fat cells produce pro-inflammatory cytokines & chemokines which results in a large inflammation response
- Chronic low grade state of inflammation –> insulin resistance
- Less anti-inflammatory T cellls in visceral fat in individuals with obesity or met syndrome
Slide 60 - 62 of Week 6
How can an increase in fat affect metabolism?
Fat can impact organs in different ways
- Largely through an increase in FFA or cytokines
- This can cause insulin resistance or inflammation
Ultimately leading to atherosclerosis
*REFER TO SLIDE 63 of Week 6 for the indepth diagram
What are is a normal weight loss? What benefits does it have?
5-10% Weight Loss
Will translate to a significant reduction in the visceral compartment
Benefits
- Decreased BP
- Improved lipid profile
- Improved Insulin sensitivity
- Decreased susceptibiltiy to thrombosis
- Decreased inflammatory markers
- Decreased risk of Heart Disease
Slide 63 in Week 6
Common drugs used for Obesity
Phentermine: acts on the brain to inhibit hunger
Orlistat: Intestinal lipase inhibitor (slows fat digestion
Liraglutide: GLP1 agonist - hunger suppresion
Naltrxone-buproprion: increases activity in the melanocortin system in the hypothalamus
Drugs not obesity approved
- Semaglutide
- Topiramate (antiepileptic drug)
Slide 71 of Week 6
Alternate Interventions to reduce weight
(Non Pharmacological)
Lifestyle Interventions
Dietary therapy
- Reduce current energy intake
- 500 cal deficit gives half a kg weight loss per week
Physical Activity
- Combination of cardio and resistance training
- Regular exercise assists with appetite control
Pyschological Therapy
- Promote mindful eating behaviours
- Manage reaction to external cues
Surgery (in depth on different card)
- Laparoscopic Gastric bypass
- Laparoscopic sleeve gastrectomy
- Adjustable Gastric band
Slide 77 - 78 in Week 6
Surgeries for weight loss
only relavent for people over BMI of 40 OR BMI in 30s if they have had lots of failed weight loss attempts & a high risk profile
Laparoscopic bypass
- Can place client at risk of micronutrient deficiency due to lack of absorption of nutrients within the stomach
Laparoscopic sleeve gastretomy
- Prone to regurgitating the meal
Adjustable Gastric band
- Can not be beneficial if the individuals drink their calories
Slide 79 in Week 6
