Page 1:

• Topic: Obesity/ Excess Adiposity EIT

Page 2:

• Objectives:

  • Review the incidence of obesity in New Zealand and understand how these stats are derived

  • Understand the factors that influence obesity

  • Explain the pathophysiology of obesity

  • Understand the complications of obesity and the implications for health and disease

  • Identify assessments used to monitor and manage obesity

• Date: 14 February 2024

Page 3:

• Definition of Obesity:

  • Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health.

  • A body mass index (BMI) over 25 is considered overweight, and over 30 is obese.

  • Most population obesity statistics are reported using BMI (body mass index, kg/m2)

• Date: 14 February 2024

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• Limitations of BMI:

  • BMI is not a direct measure of body fatness because it is a measure of excess weight rather than excess body fat

  • Factors such as age, sex, ethnicity, and muscle mass can influence the relationship between BMI and body fat

  • It is more useful as a population level statistics rather than an individual measure

• Date: 14 February 2024

Page 5:

• New Zealand Obesity Statistics:

  • Depending on the data, NZ has the third or fourth highest obesity rates in the world

  • 1 in 3 NZ adults (15 and over) are classified as obese

  • Prevalence by ethnicity:

    • Pacifica 71.3%

    • Maori 50.8%

    • European/other 31.9%

    • Asian 18.5%

  • 12.7% of NZ children

• Date: 14 February 2024

• Source: New Zealand Health Survey 2020/21

Page 6:

• Should we consider using other terms rather than obesity?

  • The term "obese" has several negative connotations

  • Research suggests using terms such as "weight," "BMI," "weight problem," or "excess weight" are preferred by patients

• Date: 14 February 2024

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• Factors that influence obesity:

  • TASTE

    • Food preferences

    • Time convenience

    • Allergy/intolerance

    • Accessibility

    • Knowledge

    • Habit

    • Cost

    • Social and cultural aspects

  • Macros

    • Satiety

    • Fiber

    • Genetics

    • Age

    • Stress

    • Hormones

    • Gender

    • Enjoyment

    • Safety

    • Affordability

    • Motivation

    • Physical ability

    • Time

    • Habit

    • Post-exercise activity

    • NEAT

    • Resistance/cardio

  • Macro interactions

  • FOOD

  • EXERCISE

• Date: 14 February 2024

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• Risk factors for obesity:

  • There is no single cause – there are many factors that impact the development of obesity

  • Unhealthy diet

  • Physical inactivity

  • Stress

  • Smoking

  • Socioeconomic factors

  • Genetic factors (at least 8 genes)

  • Metabolic disorders

  • Hormone imbalances

• Date: 14 February 2024

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• Concerns about obesity:

  • Obesity significantly raises the risk of serious health conditions such as diabetes, cardiovascular problems, dementia, some cancers, mental illnesses, and chronic pain

• Date: 14 February 2024

• Source: Ministry of Health. 2015. Understanding Excess Body Weight: N Wellington: Ministry of Health.

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• Adipose cells are metabolically active:

  • Produce hormones and cytokines that regulate food intake, lipid storage, metabolism, insulin sensitivity, and female reproduction

  • Influence the immune system, vascular homeostasis, and BP

  • Stimulate angiogenesis

• Date: 14 February 2024

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• Food intake- appetite:

  • HORMONES

    • Stomach

    • Adipose tissue

    • Taste

    • Cerebral cortex

    • Smell

    • Ghrelin

    • Leptin

    • Sight

    • Increases appetite

    • Decreases appetite

    • Emotions

    • Stimulates

    • Inhibits

    • Hypothalamus

    • Nutrients

    • GI hormones

    • Insulin

    • Neural signals

    • Adipose

    • GI tract

    • Food intake

    • Energy

    • Energy absorbed

    • Ingested

• Date: 14 February 2024

• Source: Guyton AC, Hall JE. Textbook of medical physiology. 10th edn. Philadelphia: Saunders; 2000.

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• Control of appetite:

  • Normal body weight

  • Obesity

  • Normal fat cell mass

  • Increase in fat cell mass means that Leptin level normal

  • Leptin level increased excessively affecting the Hypothalamus

  • Resulting in Decreased appetite and food intake

  • Leptin resistance and other hormone Increased metabolism action

  • Increased sympathetic activity

  • Increased appetite and food intake

  • Decreased metabolism

  • Sustained sympathetic activity

• Date: 14 February 2024

• Source: Guyton AC, Hall JE. Textbook of medical physiology. 10th edn. Philadelphia: Saunders; 2000.

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• The link between obesity and health:

  • Hypertrophic adipocytes

  • Normal adipocytes

  • Impaired lipid metabolism

  • Excess energy intake

  • Altered adipokine secretion

  • Immune cell infiltration

  • Inflammation

  • Insulin resistance

  • Preadipocyte recruitment

  • Preadipocytes

  • White adipose tissue

  • Lipid accumulation

  • Pre-Adipocyte

  • Liver

  • Inflammation

  • ROS

  • Insulin resistance

  • Lipid spill-over

  • Adipocyte

  • Systemic inflammation

  • ROS

  • Muscle

  • Lipid accumulation

  • Adipocyte

  • Insulin resistance dysfunction

  • ROS, Cytokines

  • MetS, T2D

• Date: 14 February 2024

Page 14:

• Obesity & chronic inflammation:

  • Excess adiposity results in increased production of free fatty acids (FFA) and pro-inflammatory cytokines

  • Excessive production of pro-inflammatory cytokines contributes to inflammatory disease

  • Chronic inflammation has been linked to many chronic diseases, including atherosclerosis, cancer, and depression

• Date: 14 February 2024

Page 15:

• Obesity & insulin resistance:

  • Free fatty acids (FFA) are an essential fuel source (From Triglycerides = blood test)

  • Enlarged adipocytes release more FFAs than normal adipocytes

  • As FFA concentrations increase, insulin's antilipolytic action is inhibited = more FFA

  • High FFA = decrease glucose uptake in muscle

  • Muscle tissue – including cardiac become insulin resistant

  • This is insulin resistance

• Date: 14 February 2024

Page 16:

• Health complications of obesity:

  • Insulin resistance

  • Insulin resistance: tissues unresponsive to insulin especially muscle, liver, fat cells

  • Impaired glucose tolerance

  • Hyperglycemia

  • Dyslipidemias: ­ triglycerides, ­ LDL cholesterol, ↓ HDL cholesterol

  • Metabolic syndrome – pre-diabetes

• Date: 14 February 2024

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• Health complications of obesity:

  • Type 2 Diabetes

    • Higher risk factor for those with central obesity

  • Gallbladder and liver disease

    • 3-4 fold increased risk of gallstones

    • Steatohepatitis

  • Mortality

    • 12-fold greater mortality in the 25-35 age group

• Date: 14 February 2024

Page 18:

• Health complications of obesity:

  • Cardiovascular disease

    • Dyslipidemia

    • Abnormalities of coagulation

    • Increased risk of thrombus formation

    • Atherosclerosis

  • Respiratory disorders

    • Obesity impairs respiratory function

    • High incidence of obstructive sleep apnea

  • Osteoarthritis

• Date: 14 February 2024

Page 19:

• Assessment of Obesity:

  • Health history

  • Physical examination

  • Blood analysis of:

    • Cholesterol- LDL, HDL & Triglycerides

    • C-reactive protein

    • HbA1c

    • Full Blood Count

    • Liver Function Test

• Date: 14 February 2024

Page 20:

• Evaluation of body size:

  • Body mass index (BMI)

    • BMI = weight (kg) ÷ height (m2)

  • Waist circumference

    • Central obesity versus

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• Body mass index (BMI) classification:

  • Underweight: BMI < 18.50

    • Severe thinness: BMI < 16.00

    • Moderate thinness: BMI 16.00 - 16.99

    • Mild thinness: BMI 17.00 - 18.49

  • Normal range: BMI 18.50 - 24.99

  • Overweight: BMI > 25.00

    • Pre-obese: BMI 25.00 - 29.99

    • Obese: BMI > 30.00

      • Obese class I: BMI 30.00 - 34.99

      • Obese class II: BMI 35.00 - 39.99

      • Obese class III: BMI > 40.00

• Additional cut-off points for thinness and normal range categories

• Body builder and sedentary categories

• Body mass index (BMI) and basal metabolic rate (BMR) values

Page 23:

• Waist circumference and its relation to disease risk

• Abdominal obesity and its impact on metabolic disease risk

Page 24:

• Bioelectrical impedance analysis as a method to calculate fat and fat-free mass

• Advantages of bioelectrical impedance analysis

• Ability to determine fat distribution in some versions

Page 25:

• DXA scans for body composition analysis

Page 26:

• Health at any size approach

• Avoid assuming that overweight or obese individuals are automatically unhealthy

• Consider ethnicity, culture, and lifestyle factors when providing advice

• Never assume lack of education as the reason for someone's diet or lifestyle choices

Page 27:

• Management of obesity

• Aim is prevention of obesity-related diseases

• Non-pharmacological lifestyle changes: healthy diet, regular exercise, sleep and relaxation, green prescription/lifestyle programs

• Emphasis on improving activity levels for overall health improvement

• Pharmacological/supplement options

• Bariatric surgery

Page 28:

• Childhood obesity statistics in New Zealand

• Risk factors for childhood obesity

• Higher prevalence in children from low socioeconomic status and obese parents

• Psychological factors, sedentary lifestyle, and high-calorie diet as risk factors

Page 29:

• Complications of childhood obesity

• Social and psychological issues

• Changes in bone shape

• Acanthosis nigricans

• Altered onset of puberty

• Gynecomastia in boys

• Metabolic complications: dyslipidemia, hypertension, type 2 diabetes, gallstones, osteoarthritis, and obstructive sleep apnea

Page 30:

• Treatment