obesity Flashcards
1
Q
what are the internal drivers for weight loss?
A
- gut hormones
- central nervous system
- adipose
- stress hormones: adrenaline/cortisol
- circadian rhythm: sleep deprivation
- genetics
- microbiome
2
Q
how does genetics link to obesity?
A
- MC4R mutation found in up to 5% of kids leading hyperphagia
- leptin deficient individuals can be treated with Leptin to treat obesity
- appetite is genetically determined with a growing number of genetic mutations associated with small increases in appetite and high prevalence of obesity
- twin studies of identical an non identical pairs confirms high heritability of weight
3
Q
how does the microbiome link to obesity?
A
- people at a higher weight have less variety and quantity of microbes in their gut
- obese mice who receive a faecal transplant from a slim person lose weight but unfortunately this is not replicated in humans
- emerging hypothesis of a feedback loop via microbe metabolites SCFA and vagal signalling to the brain
4
Q
what are the external drivers of energy intake?
A
- environment
- economic
- social
- cultural
- education
5
Q
what is energy expenditure?
A
- BMR increases as you gain weight and decreases as you lose weight
- muscle is more metabolically active
- influenced by age/genetics
- body ‘protects’ from weight loss through metabolic adaptations to weight loss and hunger in response to weight loss
6
Q
how does weight loss slow down?
A
- energy out: as we lose weight the body metabolism slows, therefore, we burn less energy at rest
- energy in: feedback regulation of body weight. the body is likely to resist weight loss by increasing appetite
- for every 1kg of weight loss, appetite may increase by 100 calories/day which is a real challenge for maintaining sustainable weight loss
7
Q
what are some important considerations when advising on dietary approaches for weight loss?
A
- nutritionally adequacy
- cultural acceptance
- economic affordability
- safety
- efficacy
8
Q
what are the general principles for a healthy diet and lifestyle?
A
- rich in high-fibre foods
- low in added sugar, refined grains and ultra-processed foods
- increased physical activity especially important for weight maintenance
- contains high quality protein foods
- realistic goal setting
- healthcare professional support may be useful
9
Q
what are the considerations of a low carbohydrate diet?
A
- hypoglycaemic medication: may be necessary especially for patients with type 2 diabetes
- cardiovascular disease: total dietary fat intake may increase alongside reduction in carbohydrate intake
- dietary fibre: a reduction in whole-grain carbohydrate intake may result in inadequate fibre intake
10
Q
what are the considerations of a Mediterranean diet?
A
- weight loss
- chronic disease risk: associated with reduced risk of type 2 diabetes and CVD risk in those at high risk
- increased physical activity, improved diet quality, weight management, smoking cessation and stress reduction are all key lifestyle strategies to lower CVD risk
11
Q
what are the considerations of meal replacements and LEDs?
A
- HCPs anxious regarding rapid weight loss and weight regain appear unfounded
- greater weight loss associated with greater patient compliance
- medication titration
- side effects
- HCP support to aid compliance during total dietary replacement, food reintroduction and long-term weight maintenance support essential
12
Q
what are the considerations of intermittent fasting?
A
- lack of high-quality RCTs to confirm efficacy, but may provide metabolic benefit
- hypoglycaemic medication: may be necessary to adjust medication for patients, especially those with type 2 diabetes on fasting days
13
Q
what are the predictors of weight loss success?
A
- diet quality: reduction in ultra processed foods and increased in unprocessed foods
- developing behavioural and self-monitoring skills, relapse prevention, social support
- support
- physical activity
- individualisation
14
Q
what are the general categories of drugs used in primary care for obesity?
A
- appetite suppressants including stimulants and serotonergic drugs
- bulking agents, diuretics and thyroxine should be avoided
- type 2 DM drugs: metformin and acarbose are not licensed and have no proven benefit
15
Q
what are the key features of the drug ‘orlistat’?
A
- currently licensed in the UK
- a gastric and pancreatic lipase inhibitor
- can cause fatty stools
- results in 30% less fat absorbed = 200 calories on average
- consider need for vitamin D supplements
- not licensed in children
- should be avoided in >75 years
- no long term data on clinical outcomes
