Week 3 - Energy Balance Flashcards
What are some values that can be taken to determine if someone is overweight? (8)
- Percent body fat
- Waist circumference
- Hip circumference
- Waist:hip ratio
- Waist:height ratio
- BMI
- BMI + waist
- Fat mass index (FMI)
Name some health risks related to excess body fat
- CVD - CAD, CVA, HTN
- T2DM
- Hyperlipidaemia
- Sleep disorders
- MH
- Fatty liver and gallbladder disease
- CA’s
- Respiratory problems
- Increased risk with surgery and anaesthesia
- Chronic pain
- Infertility, erectile dysfunction
What is the optimal BMI for someone over 65yo?
25-30kg/m2
Name regulators of food intake in the body (4)
- Neuronal influences from the GIT (mechanoreceptors - gastric distention)
- Energy stores (insulin, leptin, resistin, adiponectin)
- GIT signals (cholecystokinin, glucagon-like peptide 1, ghrelin)
- Neuropeptides in the brain
What is leptin, where is it secreted?
Leptin is a hormone secreted from adipose tissue
How does leptin work? What does it do?
- Created in the Ob gene
- Role in long term energy balance
- Obese people have excessively high leptin levels
- Increases appetite, increases metabolic rate and inhibits neuropeptide Y secretion
Leptin moves into the blood stream, signalling the hypothalamus to reduce or stop the drive to eat after reaching the “set point” for the body’s total fat content
What does Neuropeptide Y (NPY) do?
Increases appetite and decreases sympathetic nervous system (SNS) effects on metabolic rate
What are adipocytes and what influences them?
- Adipocytes are specialised connective tissue that are lipid storing cells
- The number and size of fat cells varies, influenced by food intake, activity levels, and genetics
What are two ways adipocytes increase?
Hypertrophy and hyperplasia
What FITT principles are applied to exercise to create an energy deficit
- Frequency: 5+ days a week
- Intensity: moderate continuous, or high intervlas
- Time: 30+ mins a day or 60 mins walking
- Type: mainly aerobic with some resistance
What are some health risks of a negative energy balance?
- Amenorrhoea and OP risk
- Malnutrition
- Electrolyte imbalance
- Oedema
- Death
- Cardiac arrhythmias
What are some conditions that can cause negative energy balance?
- Drug induced aversion (appetite suppressants; amphetamines, chemotherapy)
- Disease associated with cachexia (renal failure, cancer)
- Mental conditions (anorexia)
What does RED-S stand for? What is it about?
Relative Energy Deficiency in Sport
- Consequence of energy imbalance
- High energy expenditure, inadequate energy intake = net energy deficit
What is the female athlete triad?
A part of RED-S affecting females
- Energy drainage (psychological and physical fatigue)
- Amenorrhoea (loss of menstrual cycle for >3 months) and osteoporosis
What are some short term consequences for females in the female athlete triad?
- Stress fractures
- Low body and muscle mass
- Depression
What are some long consequences for females in the female athlete triad?
- Increased risk of OP
- Reduced risk of oestrogen dependent cancers
- Potential fertility problems
What are some ways to treat atheletic amenorrhoea?
- Reduce training volume by 10-20%
- Increase energy intake by 5-10%
- Calcium intake ~ 1500mg a day
- Maybe, contraceptive pill for oestrogen source
What are some consequences for males with RED-S?
- Decreased testosterone levels to lower end of normal stage
- Reduced fertility potential (lower sperm count, reduced sperm mobility)
- Potential effects on bones
Who’s at risk of RED-S?
- Those with high training volume
- Those with weight loss/aesthetics as a goal
What are some factors to consider regarding PA, sedentary behaviour, body composition and male reproductive system?
- Higher mET levels associated with higher sperm mobility
- Sedentary time - no changes to semen quality
- Obesity associated with decreased fertility and erectile dysfunction
What are some effects cycling may have on female reproductive function?
- Cycling: perineal compression associated with erectile dysfunction
- Increased intrascrotal temperature alters sperm viability
