prof.dr.selma karabey

Importance of Nutrition

Principles of Balanced DietMeasuring Nutritional Status and

Nutritional Disorders

Prof.Dr.Selma KARABEY

Nutrition: “The Good, the Bad, and the Ugly”

• Nutrition is the intake of food, considered in relation to the body’s dietary needs.

• Good nutrition – an adequate, well balanced diet combined with regular physical activity – is a cornerstone of good health.

• Poor nutrition can lead to reduced immunity, increased susceptibility to disease, impaired physical and mental development, and reduced productivity.

Balanced Diet

• An unhealthy diet is one of the major risk factors for a

range of chronic diseases, including cardiovascular diseases, cancer, diabetes and other conditions linked to obesity.

• Specific recommendations for a healthy diet include: eating more fruit, vegetables, legumes, nuts and grains; cutting down on salt, sugar and fats.

• It is also advisable to choose unsaturated fats, instead of saturated fats and towards the elimination of trans-fatty acids.

Balanced Diet-2 For diet, recommendations for populations and individuals should include the following:• achieve energy balance and a healthy weight• limit energy intake from total fats and shift fat consumption

away from saturated fats to unsaturated fats and towards the elimination of trans-fatty acids

• increase consumption of fruits and vegetables, and legumes, whole grains and nuts

• limit the intake of free sugars• limit salt (sodium) consumption from all sources and ensure

that salt is iodized

Nutritional Elements

• Protein 10-20% • Carbohydrate 50-70% • Fat 20-30% • Vitamins• Minerals • Water

Special groups for nutrition

• Infants and young children • School age children• Fertile women• Pregnants• Breastfeeding• Elderly• Handicapped people

Carbohydrates

• Carbohydrates are our body's main energy source.• Our brain is fueled by carbohydrates.• Carbohydrates occur in a variety of forms: simple

sugars, more complex starches and fiber.• They are found naturally in legumes, grains,

vegetables, fruits and milk. They're also added to baked goods and many other foods.

Carbohydrates

• We have to get 45 to 65 percent of our daily calories from carbohydrates.

• Carbohydrates have 4 calories a gram. • Based on a 2,000-calorie-a-day diet, this amounts to

900 to 1,300 calories a day, or about 225 to 325 grams.

Carbohydrates

Fiber;• Fiber is the part of plant-based foods that our body

doesn't digest and absorb. There are two basic types of fiber: soluble and insoluble.

• Soluble fiber may help improve our cholesterol and blood sugar levels. Oats, dried beans and some fruits, such as apples and oranges, are good sources of soluble fiber.

• Insoluble fiber adds bulk to our stool and can help prevent constipation. Vegetables, wheat bran and other whole grains are good sources of insoluble fiber.

Carbohydrates

Sugar• All sugar, whether natural or processed, is a type of

carbohydrate that our body uses for energy.• Sugar occurs naturally in some foods, including fruits,

vegetables, milk and some grains. • Sugar is also added to foods and beverages. These

added sugars do little more than add calories to our diet. Many processed foods that have added sugar also contain solid fats.

Protein

• Protein is an important nutrient, essential for growth and development.

• All the cells of our body include protein.• Protein is also an important source of calories and

energy.• Both plant-based and animal-based foods provide

protein.

Fats

• Fats aren't necessarily bad for us. • Dietary fat is a nutrient that helps our body absorb

essential vitamins, maintains the structure and function of cell membranes, and helps keep our immune system working.

• Some types of fat, though, may increase our risk of heart disease and other health problems.

• Fat also has a lot of calories, increasing the risk of weight gain.

Fats

Saturated fat• Saturated fat is most often found in animal products,

such as cheese, red meat, poultry, butter and whole-milk products.

• Other foods high in saturated fat include those made with coconut, palm and other tropical oils.

• Saturated fat may increase our risk of heart disease and type 2 diabetes.

• We have to limit saturated fat to no more than 10 percent of our total calories

Fats

• Trans fat• Trans fat occurs naturally in some foods, especially

foods from animals. But most trans fat is created during food processing through partial hydrogenation of unsaturated fats.

• Trans fat is found in some types of margarine, shortening, snack foods and commercial baked goods.

• Trans fat can increase our risk of heart disease.

Cholesterol• Cholesterol is vital because it helps build our body's

cells and produces certain hormones.• But our body makes enough cholesterol to meet its

needs — we don't need any dietary cholesterol. • Excessive cholesterol in our diet can increase our risk of

heart disease and stroke.• Dietary cholesterol comes from animal products, such

as meat, poultry, seafood, eggs, butter and other dairy products.

Sodium• Some sodium is vital because it helps maintain the

right balance of fluids in our body, helps transmit nerve impulses, and influences the contraction and relaxation of muscles.

• Too much sodium, though, can be harmful, increasing our blood pressure and the risk of heart disease and stroke.

Direct Methods of Nutritional Assessment

Nutrition is assessed by two types of methods; direct and indirect.

The direct methods deal with the individual and measure objective criteria, while indirect methods use community health indices that reflects nutritional influences.

Direct Methods of Nutritional Assessment-2

These are summarized as ABCD

• Anthropometric methods• Biochemical, laboratory methods• Clinical methods• Dietary evaluation methods

Indirect Methods of Nutritional Assessment

These include three categories:• Ecological variables including crop productio• Economic factors e.g. per capita income, population

density and social habits• Vital health statistics particularly infant and under 5

mortality and fertility index

Measuring Nutritional Status

Anthropometric Methods

• Anthropometry is the measurement of body height, weight and proportions.

• It is an essential component of clinical examination of infants, children and pregnant women.

• It is used to evaluate both under and over nutrition.• The measured values reflects the current nutritional

status and don’t differentiate between acute and chronic changes .

Other anthropometric Measurements

• Mid-arm circumference • Skin fold thickness• Head circumference• Head/chest ratio• Hip/waist ratio

Measurements for adults Height:

The subject stands erect and bare footed on a stadiometer

with a movable head piece. The head piece is leveled with skull

vault and height is recorded to the nearest 0.5 cm.

Weight Measurement

• Use a regularly calibrated electronic or balanced-beam scale.

Spring scales are less reliable.

• Weigh in light clothes, no shoes

• Read to the nearest 100 gm (0.1kg)

Nutritional Indices in Adults

• The international standard for assessing body size in

adults is the body mass index (BMI).

• BMI is computed using the following formula: BMI =

Weight (kg)/ Height (m²)

• Evidence shows that high BMI (obesity level) is

associated with type 2 diabetes & high risk of

cardiovascular morbidity and mortality

BMI (WHO - Classification)

• BMI < 18.5 = Under Weight• BMI 18.5-24.5 = Healthy weight range• BMI 25-30 = Overweight (grade 1 obesity)• BMI >30-40 = Obese (grade 2 obesity)• BMI >40 = Very obese (morbid or grade 3

obesity)

Waist/Hip Ratio

• Waist circumference is measured at the level of the umbilicus to the nearest 0.5 cm.

• The subject stands erect with relaxed abdominal muscles, arms at the side, and feet together.

• The measurement should be taken at the end of a normal expiration.

Waist circumference• Waist circumference predicts mortality better than any

other anthropometric measurement.• It has been proposed that waist measurement alone can

be used to assess obesity, and two levels of risk have been identified

MALES FEMALE

LEVEL 1 > 94cm > 80cm

LEVEL2 > 102cm > 88cm

Hip Circumference

• is measured at the point of greatest circumference around hips and buttocks to the nearest 0.5 cm.

• The subject should be standing and the measurer should squat beside him.

• Both measurement should taken with a flexible, non-stretchable tape in close contact with the skin, but without indenting the soft tissue.

Interpretation of WHR

• High risk WHR= >0.80 for females and =>0.95 for males

• Indicates central (upper body) obesity and is considered high risk for diabetes and CVS disorders.

• A WHR below these cut-off levels is considered low risk.

DIETARY ASSESSMENT

• Nutritional intake of humans is assessed by five different methods. These are:

– 24 hours dietary recall– Food frequency questionnaire– Dietary history since early life– Food dairy technique– Observed food consumption

24 Hours Dietary Recall

• A trained interviewer asks the subject to recall all food and drink taken in the previous 24 hours.

• It is quick, easy and depends on short-term memory, but may not be truly representative of the person’s usual intake.

Food Frequency Questionnaire

• In this method the subject is given a list of around 100

food items to indicate his or her intake (frequency and

quantity) per day, per week and per month.

• Inexpensive, more representative and easy to use.

DIETARY HISTORY

• It is an accurate method for assessing the nutritional status.

• The information should be collected by a trained interviewer.

• Details about usual intake, types, amount, frequency and timing needs to be obtained.

• Cross-checking to verify data is important.

FOOD DAIRY

• Food intake (types and amounts) should be recorded

by the subject at the time of consumption.

• The length of the collection period range between

1-7 days.

• Reliable but difficult to maintain.

Observed Food Consumption

• The most unused method in clinical practice, but it is

recommended for research purposes.

• The meal eaten by the individual is weighed and contents

are exactly calculated.

• The method is characterized by having a high degree of

accuracy but it’s expensive ,also needs time and efforts.

Interpretation of Dietary Data

1. Qualitative Method• Using the food pyramid and the basic food groups

method.• Different nutrients are classified into 5 groups (fat

and oils, bread and cereals, milk products, meat-fish-poultry, vegetables and fruits)

• Determine the number of serving from each group and compare it with minimum requirement.

Interpretation of Dietary Data/2

2. Quantitative Method

• The amount of energy and specific nutrients in each food consumed can be calculated using food composition tables and then compare it with the recommended daily intake.

• Evaluation by this method is expensive and time consuming, unless computing facilities are available.

Initial Laboratory Assessment

• Hemoglobin estimation is the most important test, and useful index of the overall state of nutrition. Besides anemia, it also tells about protein and trace element nutrition.

• Stool examination for the presence of ova and/or intestinal parasites

• Urine dipstick and microscopy for albumin, sugar and blood

References • Oxford Textbook of Public Health, Food and Nutrition, Roger Detels, Robert

Beaglehole, Mary Ann Lansang, Martin Gulliford, Oxford Univercity Press, 2009• IMPROVING CHILD NUTRITION, The achievable imperativefor global progress,

United Nations Children’s Fund (UNICEF)April 2013• Global nutrition policy review:What does it take to scale up nutrition action?

World Health Organization 2013• Essential Nutrition Actions: improving maternal, newborn, infant and young

child health and nutrition, World Health Organization 2013• WHO child growth standards and the identification of severe acute

malnutrition in infants and children, A Joint Statement by the World Health Organization and the United Nations Children’s Fund, World Health Organization and UNICEF 2009

• Infant and young child feeding : model chapter for textbooks for medical students and allied health professionals, World Health Organization 2009

• Halk Sağlığı Temel Bilgiler, Toplum Beslenmesi, Prof.Dr.Çağatay Güler, Prof.Dr.Levent Akın, Hacettepe Üniversitesi Yayınları 2012

Web Sources

• Healthy diet: Do you follow dietary guidelines?,Dr.John Noseworthy,

http://www.mayoclinic.com/health/how-to-eat- healthy/MY02264/NSECTIONGROUP=2 (last access date: 11.12.2013)• Assessment of Nutritional Status, Abdelaziz Elamin, Collage of

Medicine Sultan Qaboos University, Oman http://www.pitt.edu/~super7/19011.../19801.ppt (last access date:12.11.2013)