Weight Management

Unit 2: Applying the principles of nutrition to a physical activity programme

Session

Aims

To understand the relationship between body weight, physical activity and nutrition in relation to national guidelines and accepted good practise. To understand how to collect and utilise valuable nutrition information

Learning Objectives

By the end of this session the learner will

•Be able to explain the health risks associated with popular diets and fads and the performance implications of severe energy restriction•Be able to explain the components of energy expenditure, the energy balance equation, basal metabolic rate and daily energy requirements•Be able to identify typical energy expenditure for different activities•Be able to explain and interpret different methods of body composition that determine health risk in relation to weight•Be able to explain how to identify the signs and symptoms of disordered eating patterns

Popular Diets

Dietary Method Reasoning Problems

Fasting

Helps to detoxify many systems of body

Creates negative energy balance – weight loss

Rests the digestive system

Risk of dehydration Lack of essential nutrients Lack of energy Increased headaches, aches

and pains, allergies and bad breath

Very Low Calorie

Doctor supervised replacement shakes and bars

Often only 800 kcal/day Fortified with daily

requirements of vitamins and minerals

Designed for the obese to achieve rapid weight loss

Fatigue, constipation, nausea or diarrhoea

Possible gall stone formation Low bioavailability of many of

fortified nutrients Only a short term approach

Calorie Counting Groups

Group involvement creates accountability

Calorie intake controlled Guidance of foods to eat

provided

Tends to be a short term fix ‘Yoyo’ dieting cycle common Nutrient intake may be

compromised

Popular DietsDietary Method Reasoning Problems

Meal Replacement

Control the intake of food with calorie counted meals and shakes

Usually 1200-1500 kcal Removes the complexity of

calorie counting for consumer

Boredom and taste fatigue Lack of energy Low bioavailability of many of

fortified nutrients Low adherence

Food Combining

CHO digest better in alkali environmentProteins digest better in acidic environmentFoods should be separated and eaten at different times

Erratic blood sugar responses from high CHO to no CHO

Very restrictive meals May lack vitamin A, D, B12,

zinc and calcium due to low animal intake

Fat-burning Supplements

Creates a thermogenic effect in body

Boost the metabolism to burn body fat

May cause illness – even heart attack, seizures and stroke

May cause arrhythmia May cause depression,

nervousness or insomnia

Distribution of Adipose Tissue

Where we store body fat is influenced by

• genetics

• gender

• hormonal dominance

Two main categories of body fat distribution nationally recognised and discussed as part of health profiling

• gynoid or pear shaped obesity

• android or apple shaped obesity

Obesity and Health Risk

There are several methods of assessing health risk in relation to body weight

• Body Mass Index

• Abdominal circumference

• Waist to Hip ratio

Whilst these methods do not specifically measure levelsof body fat, they are nationally recognised methods of assessing health risk in relation to weight and body shape

Health Risk TaskStudents to pair up and complete each of the health assessment methods and to interpret their results

Classification of Overweight and Obesity by Body Mass Index (BMI)Obesity Class BMI (kg/m2)

Underweight <18.5 Acceptable 18.5 – 24.9Overweight Special Attention 25 - 29.9 Obesity Medical Referral I 30 – 34.9Severe Obesity II 35 – 39.9Morbid Obesity III >40

Waist/Hip Risk Male FemaleHigh risk > 1.0 > 0.85Moderate risk 0.90 – 1.0 0.80 – 0.85Low risk < 0.90 < 0.80

Low Risk High RiskMen < 94 cm ( < 37 inches)Women < 80cm ( < 32 inches)

Men > 102 cm ( > 40 inches)Women > 88cm ( > 35 inches)

The Starvation Response

This response is thought to hark back to hunter-gatherer days where the body prepared in times of plenty for times of famine and vice versa

In times of dietary restriction or lack the following occurs

• body will utilise some body fat for energy to make up energy deficit

• to lower metabolic rate muscle mass is also ‘burned’ to provide fuel

• body increases its ability to store fat in readiness for when food is available again

• appetite is also heightened to drive behaviour for finding food

Basal Metabolic Rate (BMR)

• base level of energy needed to keep bodily functions ‘ticking over’

• comprises the largest chunk of out daily energy needs

• brain averages 600 calories a day

Thermal Effect of Food (TEF)

This is a fancy way of saying how much energy it costs the body to eat and then digest the food we eat !

• in males this accounts for around 6 – 10 % of daily energy needs

• in females this accounts for around 6 – 7 % of daily energy needs

Thermal Effect of Activity (TEA)

• this is the amount of energy that our body uses up doing daily activities.

• the TEA is the largest component of energy usage that we can affect

• 20 – 40 % of our daily energy needs are related to our activity levels

Daily Energy Needs

• energy intake is approximated for women to 2000 calories per day

• energy intake is approximated for men to 2500 calories per day

These are very basic and general guidelines that do not take into account any specific individual requirements….

Harris Benedict Formula provides a better estimate of individual daily energy needs taking into account the following:

• gender• age• height• weight• activity levels

Energy Expenditure Task

Use the Harris Benedict Formula to determine an estimate of your specific daily energy needs

1.Choose the correct equation for your gender

2.Input the correct figures for your height in cm, weight in kg and age and complete calculation to determine BMR

3.Select the activity description that most closely represents your current level of activity

4.Calculate your daily energy needs by multiplying your activity figure by the initial BMR previously calculated

Creating an Energy Deficit

To avoid the starvation response we must be careful how we cause energyDeficit whether by diet alone or through diet and exercise:

• The ACSM advise a 250 – 500 kcal deficit

• It is suggested this may cause ½ lb – 1lb loss per week

It should be pointed out this is only a guideline and will be subject to individual variation

• diet and exercise combined has been shown to be more successful than diet alone!

• Warning – 500kcal dietary deficit and increased exercise combined creates a much larger calorie imbalance

• exercise increases nutrient needs of body – decrease in food will not provide for this!

Creating an Energy Deficit

Using the Harris Benedict formula, dietary restrictions listed and activity tables in the manual determine what the energy deficit would be for the following people

Energy Deficit Task

Jane David

1.62 m tall75kg in weightAged 37Lightly active

1.85m tall95kg in weightAged 45Ligthtly active

Walk dog briskly 30 mins every dayCleans house 45 mins every other day

Wants to jog 20 mins 3 times a weekPlays 1 hour badminton once a week

Currently eats 2300 kcals per dayWill give up daily 200 kcal chocolate barWill cut out 150 kcal afternoon snack

Currently eats 3100 kcals per dayWill give up evening beer (180 kcals)Will eat apple as daily snack instead of large crisps (drop of 215 kcals)

Using the Harris Benedict formula, dietary restrictions listed and activity tables in the manual determine what the energy deficit would be for the following people

Energy Deficit Task

Jane David

Daily energy needs: 2052 Kcals Daily energy needs: 2731 Kcals

Exercise: Walking 163 kcalsCleaning 146 kcals

Exercise: Jogging 183 kcalsBadminton 356 kcals

Dietary restriction: 350 kcals Dietary restriction: 395 kcals

Energy losses (diet + activity):513 kcals on non cleaning days659 kcals on cleaning days

Energy losses (diet + activity):578 kcals on jogging days751 kcals on badminton day

Energy deficit on 2300 kcal diet:

- 265 kcals on non cleaning days- 411 kcals on cleaning days

Energy deficit on 3100 kcal diet:

209 kcals on jogging days382kcals on badminton day

Dietary Interventions

• frequency of meals

• insulin response

• macro nutrient balance

• bio-chemical individuality

Meal Frequency

Research has shown that regular meals (3 per day) is recommended

1. less hunger due to more stable blood sugar

2. metabolism maintained

3. more likely nutrient balance

Effects of Insulin

Blood sugar

Meal

Refined foods - Insulin

• high GI foods

baked goods, biscuits, breads, cakes,ice cream, sweet sauces, soft drinks,pizza, pasties, and pastries

• cause a large/fast spike in blood glucose

• post insulin hypoglycaemia

Insulin Resistance

• elevated insulin leads to a fat storing internal environment

• elevated insulin suppresses the use of fat as a fuel

• chronic high insulin over time leads to insulin resistance

• insulin resistance is associated with high body fat levels and low activity levels

Reducing Insulin Levels

• improving diet is most significant factor

• CV and resistance work can

reduce abdominal body fatreduce insulin resistancemaintain muscle mass and metabolic rate

Macronutrient Balance

• higher protein/fats diets should moderate CHO

• higher CHO diets should moderate protein and fats

• this helps avoid the combined effect of excess calories in the presence of excess insulin

Individuality

We are very different on the outside

We are very different on the inside

Individuality

• genetics and gender may vastly change the type of fuels needed

• this is why different people succeed on different diets

Differing Diet Task

Split into 3 groups and review one of the dietary methods discussed in the manual

• High Wholefood Carbohydrate diet

• Ketogenic diet

• Palaeolithic diet

Determine the benefits, concerns and challenges of following each dietary method

Each group to present this back to the rest of the class

Anorexia and Bulimia

• these are both psychological based problems

• nutritional advice alone is unlikely to remedy the root of the problem

Signs and Symptoms

Anorexia NervosaPhysical:

extreme weight loss/insufficient growthconstipation/abdominal pains

dizzy spellshair loss

poor circulationdry, rough, discoloured skin

dysmenorrhoeadecreased bone density

Psychological:intense fear of gaining weightdistorted perception of body

denial of problemmood swingsBehavioural:

rituals attached to eatingsecrecy

restlessness and hyperactivitywearing baggy clothes

vomiting and/or taking laxatives

Bulimia NervosaPhysical

frequent weight changesgoing to the toilet after mealssore throat and tooth decay

swollen face & poor skindysmenorrhoea

lethargy and tirednessPsychological

uncontrollable urges to eatan obsession with food

distorted perception of bodyanxiety and depression

mood swingslow self-esteem, shame and guilt

Behaviouralbingeing and vomiting

excessive use of laxativesperiods of fasting & secrecy

excessive exerciseabnormal amounts spent on food

Seeking Assistance

• personal trainers do not have the skills necessary to advise client’s with eating disorders

• need to seek professional advice

• Eating Disorders Association

www.b-eat.co.uk

Learning Check

Can the learner

•explain the health risks associated with popular diets and fads and the performance implications of severe energy restriction

•explain the components of energy expenditure, the energy balance equation, basal metabolic rate and daily energy requirements

•identify typical energy expenditure for different activities

•explain and interpret different methods of body composition that determine health risk in relation to weight

•explain how to identify the signs and symptoms of disordered eating patterns