Obesity and eating disorders Flashcards
How is obesity and overweight defined?
Abnormal or excessive fat accumulation that presents as a risk to health. BMI over 25 is considered overweight, over 30 is obese
There are over 40 co morbidities that run alongside excess weight
Why has obesity become a pandemic?
- Food abundance and increased exposure, food on every street corner rise of convenience food
- Food palatability, increased use of colours, flavour enhancers and food layering- chemical structures which are not designed to reach satisfaction
What needs to be the daily calorie deficit for an adult to lose weight?
500-750kcal
Name 5 co morbidities associated with obesity
Type 2 diabetes, atherosclerosis, gallstones, coronary heart disease, chronic fatigue, endometriosis, hypothyroidism,
How does exercise increase energy expenditure?
- exercise increases cellular AMPK
- increases GLUT 4 activation and glucose uptake
- Increases mitochondrial activity for advanced ATP production
How can sleep disruption promote obesity?
Disrupted sleep promotes a hormonal imbalance in the body which can promote overeating and weight gain:
- reduced glucose tolerance and insulin sensitivity, need for sugar is upregulated
- Disrupts the balance of leptin and ghrelin the appetite modulating hormones. Increased ghrelin promotes hunger and unhealthy food choices
- Activate inflammatory pathways - IL-6 and TNF which can stop brain receiving leptin signals
Sleep hygiene:
- Avoid blue light before bed (depletes melatonin which we need for sleep and antioxidant) and eliminate wifi
- B6
- Magnesium glycinate or threonate
- Valerian, passionflower or chamomile tease, rescue remedy night spray
- Address stress
Discuss 5 other drivers of obesity
**1) Chronobiology:Shift work, exposure to blue light at night time and sleep deprivation is associated with obesity, dysregulation of triglycerides and cholesterol, abdominal obesity, T2DM and CV disease.
Irregular eating patterns are associated with weight gain. Late-night eating causes higher peak post prandial glucose levels, reduced lipolysis and circadian rhythm misalignment.
2) Processed foods: Palatability is a key factor in controlling appetite, point of satiation is never reached. Dopamine stimulators such as fat, starch, salt, free glutamate, alcohol, caffeine activate reward circuits in brain and trigger cravings for more, this can override satiety signals. Manufacturers combine fat sugar and salt to create a ‘bliss point’ to maximise dopamine release. Chemically laden food tricks brain into wanting more. High Fructose Corn Syrup has a strong association with obesity, NFLD and metabolic syndrome.
3) Long term high cortisol exposure - cortisol levels (overactive HPA axis) elevated in obese individuals and associated with abdominal fat.
Factors influencing HPA axis: high GI consumption, chronic stress (fight or flight mode releases glucose into the blood) , sleep deprivation, chronic pain, alcohol.
Stress can alter eating behaviours- craving for energy dense comfort foods, infants soothed with food may do same in adulthood. Cortisol will always override insulin and drive insulin resistance
4) Disrupted microbiome:
-Lack of production of SCFAs, used as fuel by intestinal cells and modulate appetite.
-Low plant fibre has shifted gut flora towards mucin utilising bacteria
- Lack of Akkermansia muciniphillia has been linked with obesity- damaged mucosal barrier= metabolic endotoxemia= disrupted insulin signalling and low grade inflammation
5) Genetic Factors:
- SNPs in fat mass and obesity associated gene (FTO) gene is a strong predictor of obesity
- VDR SNPs associated with ongoing inflammation due to altered gut permeability and so play a role in obesity
- Mutations in ADIPOQ gene associated with adiponectin deficiency which may predispose to overeating
- SNPs in SLC2A2 gene are associated with increased sugar consumption and predictor of T2DM
What is adipose tissue and what are the 3 different types?
AT is a metabolically active organ which regulates whole body energy homeostasis. Adipocytes produce lipids, steroids, inflammatory cytokines and peptide hormones eg leptin.
- White adipose tissue (WAT) long term energy storage either SAT- subcutaneous adipose tissue or VAT- visceral adipose tissue (intra-abdominal
- Brown adipose tissue (BAT) abundant in early life, better fuel burning capacity than WAT
- Beige- white adipose tissue similar to BAT
A persistent energy surplus and chronic energy imbalance can lead to….
Increased storage of adipose tissue, resulting in increased adipocyte numbers (hyperplasia) and size (hypertrophy). Genetics may determine how rapidly this happens
Hypertrophy is strongly associated with dyslipidemia, insulin resistance, T2DM and NAFLD.
Name 4 factors involved in satiety, the physiological state when further eating is inhibited by fullness
1) Mechanical stretch of the stomach via the vagus nerve (retractable bag)
2) Adipocyte hormones- leptin, ghrelin and adiponectin have chemical influences on appetite
3) Neuropeptides and neurotransmitters : neuropeptide Y (NPY) Agouti- related peptide (AGRP) , serotonin, dopamine
4) Hormones and peptides: Glucagon-like peptide (GLP-1) and cholecystokinin (CCK)
5) other hormones such as thyroid hormones, oxytocin, cortisol, insulin and glucagon play a role in appetite regulation
What is leptin?
A satiety hormone produced by adipocytes . It acts as a signalling factor from adipose tissue to the leptin receptor in the hypothalamus to regulate food intake and energy expenditure, it says we’ve had enough to eat.
What is leptin resistance?
LR is a reduced sensitivity or failure in response of brain to leptin. In obesity, leptin is high but cannot function due to LR, leading to abdominal weight gain, chronic fatigue, metabolic diseases. High adipose tissue= high leptin resistance
What is the function of ghrelin?
It is an appetite stimulating signal.
Role in long term regulation of energy metabolism and the short term regulation of feeding- increasing food intake and body weight.
- highest before a meal and lowest within 1 hour of eating
- hunger associated with dieting due to reduction in body weight (increases ghrelin)
What is adiponectin?
The most abundant circulating adipokine, lowered in obesity. BMI and visceral fat are predictors of adiponectin levels
- increases glucose uptake, insulin sensitivity and B- oxidation of fats
- Anti inflammatory
- reduced adiponectin associated with: IR, T2DM, obesity and CV disease
- low adiponectin: leptin ratio may increase oxidative stress and inflammation
How can you boost adiponectin levels naturally?
- Blueberries (anthocyanidins)
- Turmeric (curcumin) (Phase 2 detox and modulates dysregulation of adiponectin)
- omega 3s
- Fibre 40-50g day
- green tea (catechins)
- cold water therapy (teaching the body how to come out of stress)
Name 5 causes and risk factors of insulin resistance?
1) High oxidative stress eg poor sleep and environmental toxins
2) Reduced physical activity- exercise increases GLUT4 expression and modulates inflammatory mediators
3) Chronic stress- increases glucose in blood, lipids and inflammatory cytokines
4) Mitochondria dysfunction- high ROS, low ATP, decrease of GLUT4
5) Poor methylation- high homocysteine is damaging, elevated triglycerides, low adiponectin
6) Dysbiosis- drives the inflammatory process with high circulating LPS
Name 6 signs/ symptoms of insulin resistance
Lethargy, hunger, brain fog, overweight, high waist to hip ratio, high blood pressure, skin tags, acanthosis nigricans. high blood glucose levels
Describe a naturopathic approach to insulin resistance
1) Stabilise blood glucose levels (tracking can be usefull)
- Avoid processed foods with artificial engineered palatability inc sugar and sweeteners
- Protein based breakfast ( and with every meal) helps with satiety, normalises insulin secretion
- Increase fibre to slow release of glucose and slow gastric emptying
- Magnesium (decreases cravings of carbs), manganese, zinc, b vitamins (energy), chromium
2) Reduce inflammation
- Avoid inflammatory foods eg refined carbs damaged fats
- increase a rainbow of colour plant foods
- Proanthocyanidins enhance adiponectin and support microbiome- blue, purple, back foods. ginger turmeric, flaxseeds, berries, apples
- Green tea polyphenols decrease fasting glucose and HbA1c
- foods rich in prebiotic fructans, FOS, inulin
- antioxidants (Alpha lipoic acid, glutathione etc)
- Prioritise sleep - melatonin is an antioxidant
3) Optimise insulin sensitivity
- Time restricted feeding, elimination of snacks, last meal earlier and fast overnight
- Increase moderate exercise
- Vitamin D, magnesium, zinc, alpha lipoic acid, coQ10, chromium, cinnamon, fenugreek, garlic
- prebiotics inulin and FOS can modulate appetite, blood glucose and insulin levels
Discuss 5 ways to address overeating
1) Smaller portions- eat from a smaller plate
2) Chew thoroughly - till liquid if possible, helps with secretions and hormone signalling to tell you when you are full
3) Leave 4 hours between meals, fasting window such as 16:8
4) Palm size good quality protein with each meal
5) Protein based breakfast normalises insulin secretion
6) Mindful eating - enjoy the ritual of food not a secondary activity (in presence of cortisol
Which micronutrient deficiencies are common with obese individuals?
vitamin A, C, D, folate, iron, zinc and calcium
3 ways to stimulate fat loss?
1) Meal composition eg low GL, macronutrient balance
2) Breakfast is vital and should include protein and low GL carbs
3) Protein at each meal
4) Exercise daily 35 minutes low intensity
How does the body adapt to prevent starvation during caloric restriction?
- A decrease in leptin happens during weight loss which signals to the brain to eat more and expend less energy
- Pre- adipocyte proliferation occurs , increasing fat storage capacity
- Changes occur in circulating levels of gut hormones responsible for body weight homeostasis
Name 4 nutrients that may help in the reduction of obesity
1) 5- Hydroxytryptophan 5-HTP 50-100mg twice daily. Can increase feelings of satiety and aid weight loss, enhances sleep by melatonin production
2) L- Carnitine. up to 2000mg/ daily. Increases B-oxidation of fatty acids in mitochondria for efficient utilisation of fats for energy. Improves leptin resistance
3) Chromium picolinate 200-1000mcg lowers body weight, increases insulin sensitivity
4) Green tea 3-4 cups brewed- polyphenols may stimulate thermogenesis and fat oxidation
5) Conjugated linoleic acid (CLA) up to 3.4g daily. improves leptin resistance and lipolysis in adipocytes
