8a. Obesity Flashcards
(67 cards)
What is the definition of obesity?
Abnormal or excessive fat accumulation that presents a risk to health
What’s the BMI range for a healthy weight?
18.5-24.9
What’s the BMI range for overweight?
25-29.9
What’s the BMI range for obesity?
30-39.9
What, in society, has led to the rise in obesity?
Larger portion sizes
Abundance of food
Rise of convenience food
Food palatability/density
Snacking
Speed of eating
How many kcals daily are needed in deficient for an adult to lose weight?
500-750/day
Examples of conditions obesity increases the risk of
Diabetes
Arthritis
Endometriosis
Cancer
CV disease
What are the common drivers of obesity?
Sedentary lifestyle
Sleep disruption
Processed foods
Microbiome
Long-term cortisol
Genetics
Chronobiology
Why is a sedentary lifestyle a driver of obesity?
Leads to reduced energy expenditure
Why does exercise help with obesity?
Increased energy expenditure
Increased cellular AMPK
Increased GLUT4 activation/glucose uptake
Enhanced ATP production
Why is sleep disruption a driver of obesity?
Creates a hormonal imbalance that promotes overeating and weight gain
What are the hormonal imbalances associated with sleep disruption?
Reduced glucose tolerance and insulin sensitivity
Increased ghrelin levels - promoting hunger and unhealthy food choices
Activation of inflammatory pathways
Why is chronobiology a driver of obesity?
Shift work, sleep deprivation and exposure to bright light at night increase the prevalence of adiposity
What conditions/signs are more likely to increase for shift workers?
Triglycerides and cholesterol dysregulation
Abdominal obesity
T2D
CV disease
Why are shift workers more at risk of becoming obese?
Exposure to bright light
Sleep deprivation
Irregular eating patterns
Late night eating
Why can late night eating cause obesity?
Higher peak post-prandial glucose levels
Reduced lipolysis
Dysbiosis
Circadian rhythm misalignment
What should shift workers try to do to avoid obesity?
Regular eating pattern
Avoid stimulants - sugar, caffeine
Nourishing snacks
Why can processed foods be a driver for obesity?
Fats, salt, sugar, caffeine, starches all stimulate dopamine
Activate reward system to trigger cravings for more
Reward system and food palatability override satiety signals
Which artificial sweetener has a strong association with obesity, NAFLD and metabolic syndrome?
High fructose corn syrup
Why are high cortisol levels a driver for obesity?
Cortisol levels are elevated in obese individuals
Associated with enhanced abdominal fat deposition
Altered eating habits - more food, and energy dense food
Why is the microbiome a driver for obesity?
Low plant fibre content of Western diet = reduced SCFAs and increased mucus utilising bacteria
Lack of Akkermansia linked with obesity
Why is a lack of Akkermansia linked with obesity?
Low Akkermansia can contribute to damaged mucosal barrier
Leads to metabolic endotoxaemia
Leads to disrupted insulin signalling/low grade inflammation
SNPs on which genes are associated with obesity?
FTO
VDR - ongoing inflammation/gut permeability
SLC2A2 - habitual consumption of sugar
ADIPOQ - adiponectin deficiency
What is adipose tissue?
Metabolically active organ which regulates whole-body energy homeostasis
