CONCEPTS OF OBESITY

NURS: 2018, Diet Therapy

Objectives

At the end of this presentation students should be able to:

Describe the concept of desirable body weight relative to age, gender, and developmental variables

Use the concept of desirable weight in meeting the nutritional needs of individuals

State the socio-cultural, genetic, emotional, and lifestyle factors which contribute to obesity

Discuss principles of effective treatment of obesity

Objectives

Plan a modified calorie diet based on diet prescription for specified weight loss

Identify strategies for obesity preventionName the characteristics of effective obesity

intervention approachesDiscuss current research in obesity therapy

Multi-factorial influence on obesity

Factors influencing appetiteInfluence ExamplesCognitive Restraint, emotions, previous experience, conditioned

associationsSocio-cultural Religious beliefs, education, tradition, learned

experiences, economy-acquisition levelGustatory Palatability, learned/innate preferences, food-specific

satiety, nutrient-associated sensory stimuli, cephalic phase events

Neuroendocrine

Orixegenic and anorexigenic peptides, entero-insular axis, adipostatic signals, sympathetic/paarsympathetic balance

Gastrointestinal

Nutrient composition, water content, energy density, digestibility, pH, osmolarity, peptidic/hormonal/neural release, stomach size, mechanical distension, emptying rate, absorption

Metabolic Nutrient partitioning/flux, nutrient genotype interactions, hepatic metabolism

Behavioural Age, sex, socioeconomic status, occupation, meal patterns, physical activity level, pathophysiology/developmental stageFruhbeck, 2006

Terms in weight management

Normal weight- persons having BMI 18.5- 24.9 kg/m2

Overweight-adults with BMI between 25 and 29.9 kg/m2

Obesity- adults with BMI greater than 30 kg/m2

Obesity is a condition in which fat stores (adiposity) are excessive for an individual’s height, weight, gender and race to the extent that it produces adverse health outcomes.

Terms in weight management

Underweight- adults with a BMI below 18.5 kg/m2

For children, aged, or very fit and muscular, BMI definitions are not useful as obesity measure.

Variables that are important to Weight

Age- affects body composition and the presence of

muscle and fat. BMI is a measure of weight unaffected by

height. Older adults have more fat and less muscle mass due

to effects of aging and sarcopenia; children have less muscle because of developmental

changes.

Variables that are important to Weight

Gender affects body composition. Males generally have higher muscle content than

females and may have higher assessed levels of BMI

Body CompositionExercise leads to loss of fat mass and may

overtime result in higher lean body mass with resultant higher BMI.

Types of obesity

Defining Obesity based on causal factors

Simple obesity (alimentary obesity) – this happens when a person consumes more kilojoules than the body can utilise, and accounts for approximately 95% of obesity cases.

Secondary obesity results from underlying medical conditions such as Cushing’s syndrome, polycystic ovary syndrome, and insulin tumours. Other conditions can also cause secondary obesity.

Types of obesity

Defining Obesity based on causal factors

Childhood obesity – when children and adolescents are above the normal body weight for their height and age.

Obese children are at risk for long-term problems such as diabetes, hypertension, thyroid problems, and high cholesterol.

Even though these health complications are more common among adults, they can still affect children.

Obesity can affect a child’s normal growth and development.

Types of ObesityObesity may also be defined based on WHO

classifications and BMI cut-off points. Classification BMI (kg/M2)

Underweight <18.5Normal weight 18.5-24.9Moderate overweight 25.0-29.9Overweight ≥25.0Preobese 25-29.9Obesity ≥30 Obese class I 30-34.9 Obese class II 35-39.9 Obese class III ≥40

Seidell & Visscher, 2004

Treatment

Goal of obesity treatment is to :- Reduce morbidity and mortality risk and to

improve cardiovascular healthReduce the burden on the health care sectorImprove the productive sector

Tucker & Dauffenbach, 2011

Goals of obesity Therapy Weight loss- set realistic goals that are achieved in stages Change in body shape and size- (less abdominal and intra-

abdominal fat) Control of associated disorders:

Impaired glucose metabolism (diabetes, impaired glucose tolerance) Dyslipidaemia Hypertension Sleep apnoea Arthrititis

Mobility Reduction in medications Improved cardiovascular fitness Improved psychological and social factors Attainment of individual goals

Fitting into clothes Need for, ability to have operation Reduction in pain

(Omari & Caterson, 2007)

Treatment ModalitiesLifestyle modifications

Diet Physical activity Behaviour modification

Weight loss is more likely sustained if individuals who engage in non-surgical measures continue to engage in these activities after 10% weight loss is seen.

Weight loss strategies are not suitable for every group. Children- care take to maintain weight except if BMI is 95th

percentile or above Pregnant women- contraindicated; for obese women recommended

gain is 11-20 pounds Older persons- age does not preclude persons; care needs to be

taken to preserve lean body mass

Treatment Modalities

Lifestyle Modifications Diet

Weight loss occurs when calorie expenditure exceeds intake.

Dietary manipulations are the subject of many research but the data is unclear at this time; consistent is the information that calorie restriction rather than macronutrient manipulation has some effect.

Treatment Modalities- Low Calorie Diets

Diet Definition Risks and benefits

Starvation Less than or equal to 200 kcal

Loss of fluid and electrolytes, esp. K; inadequate nutrient intake, muscle loss

Very low calorie

200-800 kcal, liquid or solid; includes formal programs at medical centre and some weight loss centers

Loss of fluid and electrolytes, esp. K; inadequate nutrient intake, muscle loss may occur, used under medical supervision for extreme obesity

Low calorie Reduced cal compared to usual; liquid or solid; includes formal programs at medical centre and some weight loss centers and meal replacement drinks and packaged foods

Can be nutritionally balanced if all the food groups are included; meal replacement foods are not conducive to learning permanent new food behaviors

Tucker & Dauffenbach, 2011

Treatment Modalities- Nutrient Altered Diets

Diet Definition Risks and benefits

Low carbohydrate

Less than or equal to 100gm carbohydrate/d

Ketosis, often high fat, forbidden foods lead to inadequate nutrient intake, low fibre, may or may not have reduced carbohydrate

Moderate fat, moderate to high carbohydrate

Greater than 50% of calories as carbohydrates and 25-35% as fat

Generally balanced nutrients; may or may not be reduced calorie

Low fat or very low fat

Less than 25% calories as fat and high carbohydrate with high fibre

Increased carbohydrate can lead to high triglycerides, high volume of fibre may lead to malabsorption of some nutrients; too may low fat can lead to low HDL cholesterol and essential fats; may or may not be reduced calorie

Tucker & Dauffenbach, 2011

Treatment Modalities- Novelty Diets

Diet Definition Risks and benefits

Single Food Focus on food as contributing to weight loss (e.g. grapefruit, vinegar or cabbage soup)

Inadequate nutrient intake if only single food is ingested; boredom and lack of lifestyle management; reduced calorie only because of limiting nature of foods

Fo0d combining

Foods are eaten in set combinations felt to cause weight loss (e.g. fruit eaten only with proteins and vegetables with grains, specific foods recommended for body or blood type).

Some diets lack food groups and, therefore, are nutritionally inadequate. No specific evidence of magic to food combining; often reduced calorie because of limited intake.

Tucker & Dauffenbach, 2011

Outline for Obesity Intervention

BMI General Advise

Lifestyle programme

Adjunctive Therapy

Possibilities

18.5-24.9 Maintain weight

25-29.9 UseHigh Risk* Use Consider Pharmacotherapy30-34.9 Use Consider/use Pharmacotherapy or

VLCDsHigh Risk* Use Use Pharmacotherapy +/-

VLCDs35-39.9 Use Use Pharmacotherapy +/-

VLCDsHigh Risk * Use Use Pharmacotherapy +

VLCDs or surgery40 + Use Use Pharmacotherapy +

VLCDs or surgery

References

Frühbeck, G. (2006). Overnutrition. In M., Gibney, M. Elia, O., Ljungqvist, & J., Dowsett (Eds.), Clinical Nutrition. (pp. 30-61). Oxford, UK: Blackwell Science Ltd.

Omari, A. & Caterson, I. D. (2007). Overweight and obesity. In J. Mann & A. S. Truswell (Eds.), Essentials of human nutrition (3rd Ed.). (pp 234-248). New York, USA: Oxford University Press.

Seidell, J. C. & Visscher, T. L. S. (2004). Public health aspects of overnutrition. In M., Gibney, M. Elia, O., Ljungqvist, & J., Dowsett (Eds.), Public Health Nutrition. (pp. 167-177). Oxford, UK: Blackwell Science Ltd.

Tucker, S. & Dauffenbach, V. (2011). Nutrition and diet therapy for nurses. Boston, USA: Pearson.