Chapter 33-Fuel metabolism and Obesity Flashcards
(21 cards)
What is defined as obesity?
BMI of 35 or more
What are the trends of obesity in the US and worldwide?
US-1/3 adults and 17% of children are obese
worldwide-1.6billion (25%) of the world is overweight
What are the health consequences of obesity?
- skeletal muscle insulin resistance and development of type 2 diabetes
- Diabetes linked end-stage renal disease
- cardiovascular disease
- Neurological and psychological issues such as Alzheimer’s disease
- pulmonary disease ie sleep apnea
- Reproductive issue ie infertility and gestational disease
- GI such as colon cancer and gallstones
- Increases skin infections
- Orthopaedics ie osterarthritis
What are the treatments for obesity?
Lifestyle with low calorie diet and increased physical activity
Pharmacological options that alter nutrient absorption, increase satiety and appetite suppression
surgical treatments ie restrive gastric band and biliopancreatic diversion/duodenal switch
What is energy balance
balance of energy intake and energy expenditure (basic metabolism and physical activity)
What happens when the energy intake is equal to expenditure?
weight maintenance
What happens when energy intake is greater than expenditure?
weight gain (positive energy balance
What happens when energy intake is less than expenditure?
weight loss
What happens when there is perturbation of body weight
it is met with physiological response to counter the changes
What hormones control long term control of intake
insulin and leptin (adiposity signals)
What hormones control short term control of intake
peptide tyrosine tyrosine (PYY) and glucagon-like peptide 1 (GLP-1) induce satiety
Ghrelin induce appetitie
What are some contributors of obesity?
genetics
leptin (leptin production is proportional to amount of adipose tissue; deficiency of leptin[ar] causes hunger and severe obesity
diet and physical activity (major contributor)
what hormones induce hunger
ghrelin
What hormones induce satiety?
peptide tyrosine tyrosine (PYY) and glucagon-like peptide 1 (GLP-1)
What is the substrate oxidation and fuel preference in fed and fasted state?
skeletal muscles primarily oxidize fatty acids in the fasted state and switch to carbs in the fed state
How is substrate oxidation assessed?
indirect calorimety
What type of substrate metabolism issues have been observed in obese individuals?
low oxidation metabolism and defects in switching to carbohydrate oxidation (hyperglycemia) in response to insulin
low fat oxidation and excess FFAs signifies what? and what does it indicate?
low insulin sensitivity which is indicative of type 2 diabetes
what happens to skeletal muscles in response to insulin sensitivity?
increased neutral lipid content decreased glycolytic activity decreased glut 4 translocation decreased capillary density less mitochondrial content concomitant, lower function and impaired oxidative enzyme activity
What does exercise help with?
improving mitochondrial content, substrate oxidation, and insulin sensitivity.
What factors contribute to maintaining energy homeostasis?
extrinsic (environmental) and intrinsic (physiological, genetic) changes occur to maintain energy homeostasis
