OBESITY MANAGEMENT (Lifestyle Management (CALORIE RESTRICTION PHYSIOLOGY
PROLON STUDIES - Fasting-mimicking diet and markers/risk factors for ageing, diabetes, cancer, and cardiovascular disease. Wei 2017, 5 day fast - around 100kcals per day. Includes all essential vits and mins.
CALORIE RESTRICTION PHYSIOLOGY
- There are animal RCTs which show beneficial effects of CR (Mattison 2012, Colman 2009) - and some dubious REspective observational studies.
- Shockingly reduced calories led to weight-loss in non-obese humans but also provided fat free mass - reduced msucle is not good.
CALORIE RESTRICTION - meeting macro/micro-nutrient requirements with 30% fewer calories - is this possible?
- More efficient metabolism
- Higher protection against cellular damage
- Activation of remodelling mechanisms
- Less efficient metabolism and synthetic pathways are blocked.
- EFFECT OF ANIMAL PROTEIN ON IGF1
5. FOXO and TOR – increases SOD, autophagy.
- CR reduces IGF1, increases FOXO3a and inhibits TOR. = increased gene expression
2. Changing production of ROS by mitochondria
- Mitochondria show greatest amounts of oxidative stress
- Oxidative stress increases with age.
- Free radical generation
- Antioxidant defenses
- Cell, organelle and molecular turnover (mito production)
- REPAIR OF OXIDATIVE STRESS
- H2O2 production increases as the inner mitochondrial
membrane potential BUT calorie restriction REDUCES IT (through reduced ROS production)
- Mitochondria from CR animals generate fewer free radicals per atom of oxygen utilised in the electron transport chain
1. Reducing advanced glycation end products
- 30% CR reduction led to reduced AGEs in rat tissues (Teillet 2000)
- When adding AGEs to CR prevented increase in lifespan, just CR gave best outcomes (Cai 2008)
- Lower level of plasma AGEs lives longer.
- Health behaviour model - are they ready for change?
- What is general diet?
- What is their food preperation? Do they cook? Do they buy food prepared?
MOST IMPORTANT THING IS IF PEOPLE LIKE DIETS, If they don't like them, they won't be sustained
- Barker Hypothesis - is it possible to lose weight if been programmed?
- Initial weight loss is easy, long-term maintenance is a nightmare
- ACHIEVE AND MAINTAIN A NEGATIVE ENERGY BALANCE - Feels AWFUL
- FREQUENCY OF FOLLOW-UP IS ASSOCIATED WITH SUCCESS
- SELF-MONITORING VERY IMPORTANT
- Ghrelin is still raised a year after losing weight.
- Peptide PYY, Amylin, and CCK are all reduced from baseline even after 62 weeks.
SIRT1: Silent information regulator
AMPK: Adenosine monophosphate kinase
PGC-1α: Peroxisome proliferatoractivated receptor γ coactivator-1α
TOR: Target of Rapamycin kinase
- Compliance discussion
- Etiology of obesity
- Risk of co-morbidities
- Waist circumference / fat mass
- weight history
- medical history / drug history (steroids/insulin/GLP-1/anti-depressants)
Malnourishment: Vit D - B12 - Iron
- programmes requires 60% completion
- average weight loss of 3% with at least 30% achieving 5% WL
- BMI >40 can have surgery
- BMI 35-40 can have surgery if they have another comorbidity
(5 points lower if they diabetes)
- must be fit for surgery and committed to long-term follow-up
- how to identify good candidates? - if they have shit diet and don't exercise... what would surgery change?
- asthma/apnoea, diabetes, economic impact of leaving them, quality of life, gonadal
- patients are managed in a multidiserplinary team
- massive reduction in diabetes - but trauma increases blood glucose and insulin? higher fasting glucose is used immediately through the trauma pathways?
- economic issues both individually and NHS
- Bariatric Surgery is the most effective treatment for obesity
- Keyhole is more commonly used to reduce later complications
- gastric band (13% weight loss) (Band under stomach)
- Ideal for BMI 35-45
- 10% risk of complication (mortality 1:1000)
- 10% repeat surgery risk
- gastroplasty (17%)
- gastric bypass (27%)
- drastically reduce stomach size (food bypasses stomach and just goes to small intestine.
- 40-55 BMI
- complication 5%, mortality 1:300
- 42% surgeries
- gastric sleeve (20% weight loss) (remove 75% of stomach)
- Bilio-pancreatic divserion
- removing part of stomach and majority of small intestine
- loads of malabsorption
- endobarrier (bypass sleeve) (20% weight loss)
- very successful for diabetes patients
- Pre-op: very low energy diet <1000 kcal/day
- post op: clear liquid - to liquid - to soft - to normal
LIFELONG SUPPLMENTS REQUIRED - BOMSS
- can cause nausea and dehydration
- dumping syndrome
- food intolerance
- change in taste receptors / change in gut hormones / brain acitvation
- surgery can 'reset' the set point
- over 140/90
- increased fat mass has increased arterial stiffness
- Hypertension can be genetic - shared environment?
DIET AND LIFESTYLE
- differences in ethnicity - interheart study 2004
- effect of drugs
- effect of vegetables
- effect of polyphenols - resveratrol
- difficult without bad side effects
- orlistat reduces fat absorption by 30% - unabsorbed fat excreted in faeces
- 5% loss required in 3 months or 10% in 6 months required to maintain use. (A LOT OF WEIGHT IN A SHORT TIME)
- Overweight/obesity mortality varies from study to study - EVERYTHING IS AN ASSOCIATION
- cannot split between sheer body size and health behaviours .e.g lack of exercise, increase in sedentary behaviour
- set-point theory can explain why some people struggle to maintain weight loss
- all about management and making sure it works for the individual