Nutrition

© Katarína Babinská, 2019

1. Nutrition is important in numerous areas of medicine

Pediatrics - Growth

and development

Gynecology -

Pregnancy

Sport performance

Digestive health

Diabetology

Allergies,

intolerances

General medical

practice

Obesitology

Cardiology

Esthetic medicine

Surgery –preparation of and recovery

Toxicology (foodtoxins)

Mental health and performance

Cardiology

Oncology

Pharmacology -drug-diet interactions

Geriatry - Health of the elderly

Psychology (foodintake disorders)

Immunology

Hepatology

Nutritionists – dietarycounselling

Etc.

This applies to many health disorders

(including major health problems of current time):

● diabetes ● heart disease

● obesity ● cancer

● food allergies ● food intolerances

● digestive disorders ● liver disorders

● metabolic diseases

● and many other diseases

© Katarína Babinská, MD, PhD. MSc., 2018

katarina.babinska@fmed.uniba.sk

Nutrition/diet is important in

- disease prevention and treatment

You should

change your

diet

2. Food composition

Nutrition (diet, food)

- chemical substances provided from the external

environment into gastrointestinal (GI) system

Food - source of

- nutrients

- other food components

(bioactive substances, food additives, contaminants)

Foods

- animal origin

- plant origin

digested, absorbed and utilized in internal

environment of the body

- substances required for normal function of the body (about 30 substances)

- „must be“ substances - their lack may cause deficiency signs/diseases

e.g. Fe - anaemia,

Ca – osteoporosis,

protein – growth retardation in children, etc.

Macronutrients

1. Proteins

2. Fats

3. Carbohydrates

Micronutrients

4. Vitamins

5. Minerals

Nutrients

Nutrients and their functions

Function

• synthesis of tissues (body proteins)

• synthesis of enzymes, hormones, antibodies, plasma proteins....

• source of energy (under some circumstances)

Proteins

Amino acids

1. essential

– cannot be synthesized in the human body

– provided only by food

• adults - 8 essential AA • child - 10 essential AA

2. non - essential – can be synthesized in the body from essential AA

Structure• macromolecules composed of amino - acids (AA)

• human body - built from 20 different amino acids

Plant sources

- soy, legumes, bread, cereals, potatoes

- incomplete protein (= protein with lower biological value) = less adequate AA composition

usually poor in some essential amino acids

synthesis of body proteins is inefficient if any of the essential AA is missing !

Animal sources

- meat, fish, eggs, milk, milk products, cheese

- complete protein (protein with higher biological value)

= adequate AA composition

contains all essential AA in adequate amount

more efficient utilization of AA in synthesis of body proteins

Main food sources of protein

the barrel can never be more filled

than up to the lowest plank. in the

same way, one amino acid at the

time will limit

- by consumption of a variety of different plant foods adequate amount of AA can be supplied (e.g. in vegetarian diet)

- people consuming exclusively plant food shouldcare about the variety of their diet

I´m a vegan. What to eat,

in order to have adequate

protein intake?

Energy value of protein

17,1 kJ/ 1 g

Protein requirements

• body protein is degraded daily (obligatory loss) – needs to be replaced

• recommended protein intake: 10-15 % of daily energy intake

(or 0,8 g/kg of body weight)

• higher protein requirements (tissue synthesis)

- children and adolescents,

- pregnant and lactating females

- sportsmen

- patients (mainly chronic diseases)

Proteins Fats Carbohydrates

10-15 %

Low protein intake

• growth retardation, weight loss, oedema

• disorders of body functions (immune functions, anaemia, etc.)

Excess protein – is it healthy?

= excess energy → stored as fat → obesity

- sportsmen need a higher, but not ecxessive protein supply

- muscles are built only if high protein intake is associated with adequate

physical activity

Protein is important.

Shall I eat more

protein? - Most people have adequate or slightly

higher protein intake

- Protein rich food may be rich in fats.

- Choose low fat alternatives.

•full milk yoghurt / low fat yoghurt

•fatty meat / lean meat, etc.

• indicator of protein metabolism (proteins = N containing substances)

• the ratio between the amount of nitrogen intake into the body, usually as food, and that lost from the body (in urine and feces)

• 6,25 g protein = 1 g N

1. nitrogen equilibrium: intake of N = N losses

2. positive nitrogen balance: intake > loss

– indicates tissue synthesis and protein anabolism

• growth

• pregnancy

• lactation

• training, etc.

3. negative nitrogen balance: intake < losses

- indicates protein catabolism

• fasting

• disease

Nitrogen balance

intake loss

>

<

=

Function

- source of energy

- building components of cell membranes

- needed for vitamin absorption in the GIT

- substrate for synthesis of biologically active compounds

(prostaglandins, prostacyclins, thromboxanes, leukotriens – regulatory molecules)

... a very much discussed nutrient...

At present time dietary are a nutrient of great concern because of their

association with cardio-vascular diseases, that are main cause of death .

Fats

- triglycerides - main type of fat in food (glycerol + fatty acids)

-O-C-...=

OCH

2

CH2

CH

-O-C-...=

O

-O-C-...=

O

- fatty acids are a main building component of fats

- the fatty acid composition determines the effects of fat on the body

Composition of fats

Nutritionally important fatty acids (FA)

and their classification

1. Saturated - SFA (without double bonds)

- palmitic acid

- stearic acid

2. Unsaturated (contain double bonds in molecule)

a. Monounsaturated - MUFA(1 double bond)

- oleic acid

b. Polyunsaturated - PUFA (2 and more double bonds)

n-6: linoleic acid

arachidonic acid

n-3: linolenic acid

EPA – eicosapentaenoic (long chain n-3 FA)

DHA – docosahexaenoic (long chain n-3 FA)

Essential fatty acids

- linoleic and linolenic acid

- indispensable for the function of the body

- cannot be synthesized in the body (all the other FA can be)

- food is their only source

Saturated fatty acids - „bad, unhealthy“

- if consumed in excess - increase the risk of health disorders (currently very common)

• high blood cholesterol level

• atherosclerosis

• cardiovascular disease (myocardial infarction, stroke)

- main component of animal fats

Unsaturated fatty acids - „good“, protective effect

• decrease the risk of atherosclerosis, heart diseases

• positive effect (lowering) of blood cholesterol level

- main component of plant fats

Blood cholesterol- normal blood component if normal concentration

- excessive levels – higher risk atherosclerosis and of cardiovascular disease

Main blood cholesterol fractions

- LDL cholesterol – „bad “ – increases the risk of CVD

- HDL cholesterol – „ good“ – reverse transport of

cholesterol to liver for elimination

higher levels associated with a decreased risk of CVD

• animal

- butter, other types of animal fat

- fatty meat and meat products, fish, full milk and milk products

• plant

- plant oils and margarines (Rama, Flor, Becel),

- nuts, oily seeds (e.g. sunflower, pumpkin seed, sesame seed...)

• foods rich in n-3 FA

- fish (preferred source – rich in long chain (LC) PUFAs

- canola oil, linseed, walnuts (a-linolenic acid),

Recommended fat intake

•25- 30 % of total daily energy intake

of that

- saturated fatty acids max 10 %

- unsaturated fatty acids 20 %

- n-3 FA 1-2%

Energy value of fat: 38,9 kJ/ 1 g

Proteins Fats Carbohydrates

25- 30 %

10- 15 %

Dietary sources of fat

n-3 fatty acids

Modulate several biological pathways

Benefits:

- antiinflammatory effeect

- reduce oxidative stress

- lower risk of fatal cardiac events

- lower risk of arrythmias/atrial fibrillation

• the intake of n-3 FA is insufficient

• the ratio of n-6 : n-3 is imbalanced

(too much n-6, too little n-3)

• unsaturated acids – naturally occur in cis form (configuration)

(only small portion is naturally in trans form)

• trans forms (isomers) of fatty acids

• formed in technological fat processing (e.g. frying, production of margarines)

• adverse effects

- increase blood cholesterol level (even more than saturated fatty acids) –

- elevated risk of CVD,

- risk of diabetes mellitus, etc.

• food sources: processed fat containing foods, e.g.

ice cream, croissants, fries, crackers, fried foods

Trans fatty acids

Dietary cholesterol

Function

- component of cell membranes

- substrate for synthesis of bile acids

hormones, vitamin D

Sources

- can be either synthesized in the body or is provided by food

- contained exclusively animal foods

- mainly in offal (brain, liver, kidneys) and eggs

Dietary cholesterol and blood cholesterol

- high blood cholesterol = high risk of cardiovascular diseases

- old hypothesis:

- too much dietary cholesterol makes the blood cholesterol high

- it has been shown that mainly excess of saturated fatty acids makes the

blood cholesterol high

- the effect of dietary cholesterol on blood cholesterol level is only minor

Choose fats wisely for good health. prefer plant oils rich in unsaturated fat limit animal fats rich in saturated fat and

cholesterol increase the intake of n-3 FA avoid foods rich in trans FA

High fat intake

– increased risk of obesity, cardio-vascular disease,

cancer

Insufficient fat intake

– decrease in absorption of fat soluble vitamins,

disorders related to insufficient intake of essential

fatty acids

At present time

- the total fat intake is excessive

- saturated fatty acid intake is high

- n-3 fatty acid intake is lower than recommended

Carbohydrates

- function: energy source

Types and dietary sources of carbohydrates

1. Monosaccharides (1 carbohydrate unit in molecule)

• glucose, fructose, galactose (fruit, vegetables, honey)

2. Disaccharides (2 carbohydrate units in molecule)

• saccharose (sugar, sweets, soft drinks)

• lactose (milk, milk products)

3. Polysaccharides (10 and more carbohydrate units)

• starch – main carbohydrate in human diet

(cereals, legumes, potatoes, fruit, vegetables)

- Energy value of carbohydrates 17,1 kJ (4,1 kcal)/ 1g

Proteins Fats Carbohydrates

25- 30 %

10- 15 %

55 - 60 %

Recommended intake of

carbohydrates

• 55 – 60 % of daily energy intake

• of that mono and disaccharides:

maximum 10 % of energy

- foods rich in simple carbohydrates

= „empty calories“

- rich in calories

- usually poor in beneficial nutrients

(vitamins/minerals, dietary fibre)

Mono / disaccharides

- fast source of energy

- rapidly digested and absorbed in the gut

- rapid increase of glycaemia

- rapid increase in insulin secretion with adverse metabolic effects:

preferred fuel - glucose,

therefore fat deposition

faster onset of hunger –

blood glucose drops rapidly

down

CVD, DM risk

Polysaccharides

- „easily digested“ – similar metabolic effect as simple carbohydrates

(or just slightly lower)

- e.g. white bread !!!

Slowly digested poysaccharides

- slower and prolonged increase in glucose level

- glycaemia does not reach so high levels

- metabolically more

advantageous

- „longer term“ source of

energy - longer feeling of

satiety

- dietary fibre containing

carbohydrates

Dietary fibre

• group of chemical compounds (mostly polysaccharides)

collectively referred to as ditary fibre

a/ water soluble b/ water insoluble

• indigestible component of diet - GI secretions lack

enzymes for digestion of fibre

• fermented by microorganisms (mainly) living in the

GI system

Food sources

• plant foods (cereals, legumes, vegetables, fruits, nuts)

• recommended intake 20 - 30 g/day

• „protective nutrient“ - displays many positive effects

Water soluble fibre - in GIT absorbs water, creates a gel

reduces glucose absorption – prevents rapid increase in glycaemia

helps to reduce blood cholesterol level (enhances excretion of bile acids via

faeces and utilization od blood cholesterol for their de novo synthesis)

prebiotic – stimulates the growth of beneficiary bacteria in the colon

Effects of dietary fibre in the human body

https://image.slidesharecdn.com/funtionalfoodfinal-pdf-171130151226/95/funtional-food-

and-nutraceuticals-its-impact-on-human-health-50-638.jpg?cb=1512055198

Effects of dietary fibre in the human body

Water insoluble fibre

absorbs water in alimentary tract, increases the volume of the

GI content

enhances the feeling of satiety

stimulates intestinal motility

- lowers the passage time, thus the exposure of mucosa

to irritanting substances

- aids bowel movements – prevents constipation

prebiotic – stimulates the growth of beneficiary bacteria in the

colon

Dietary fibre - effective in prevention of obesity,

cardiovascular disease, cancer, constipation

Clinical case

• Patient Eugene– Newly diagnosed diabetes mellitus

Dietary recommendations

Nutrition is an important part of the treatment

Reduce simple carbohydrates

Prefer complex carbohydrates

Consume adequare amount of dietary fibre

......

• Why?

Carbohydrates

Vitamins

Classification

– fat soluble vitamins (A, D, E, K)

– water soluble vitamins (vitamin C and the B complex: B1, B2, B6, B12,

niacin, folate, biotin, pantothenic acid)

Function

• components of enzyme systems (co-factors)

• involved in the regulation of metabolism

• often associated with a specific function

– Vit A – vision

– Vit K – blood clotting

– Vit B12 – erythropoiesis

– Vitamin E – antioxidant

– Vitamin D – bone formation, etc.

Vitamins Function Sources

A cell division and differentiation, required

for function of the immune system,vision

milk, butter, dairy, dark green vegetables,

yellow-orange fruits and vegetables

B-1 carbohydrate metabolism grains, meat, eggs, legumes, green leafy

vegetables

B-2 energy metabolism milk, cheese, yoghurt, green leafy

vegetables, fish, liver, lean meats, yeast

B-3 energy metabolism yeast, whole grains, milk, meats, legumes

B-5 energy metabolism egg yolk, liver, fish, poultry

B-6 metabolism of proteins, fats and

carbohydrates

vegetables, whole-grain products, meat,

liver, fish, soybeans, wheat germ, fruits

B-7 energy metabolism egg yolks, yeast, liver, milk, legumes, nuts

B-9 cell division, formation of red blood cells,

prevents birth defects, protein metabolism

green leafy vegetables, citrus fruits,

legumes, yeast, orange juice

B-12 formation of red blood cells, metabolism all animal foods

C function of the immune system, synthesis

of collagen, iron absorption, antioxidant

fruits, vegetables, potatoes

D regulation of calcium and phosphorus

absorption

milk, cheese, egg yolk, margarines, butter,

liver, fish, exposure to sunlight

E antioxidant leafy green vegetables, nuts, legumes,

vegetable oils, whole grains, egg yolk

K synthesis of coagulation factors leafy green vegetables, egg yolk,

vegetable oils, dairy, meat

Sources of vitamins

• nutrition

– should be the only/main source of vitamins

(except vitamin D – sun exposure)

• some vitamins are produced in the human body

vitamin K, B12

– in small and insufficient amount

– produced by bacteria in large intestine – minimum absorption

vitamin D - sufficient amount produced in exposure to sunlight

vitamin A - sufficient amounts of provitamine (b-carotene) needed

• sources of vitamins – a variety of foods: vegetables, fruit, cereals, milk,.....

Vitamin pills

- contain „only“ vitamins

- do not fully replace healthy diet

- diet contains also other bioactive substances with biologically – strenghten the

effects of vitamins

- recommended in some conditions – disease, diet, the elderly, pregnant women...

Do I need vitamin pills?

Risks of insufficient vitamin intake

Avitaminosis

- absolute deficiency – currently very rare in developed countries

- results in disorders with typical symptoms

vit. A – night blindness, blindness (impairments of cornea)

vit. D – rhachitis

Hypovitaminosis

- results in mild forms of deficiencies – rather common

- no clinical symptoms, lower of levels in blood/tissues

- causes metabolic abnormalities and increased risk of non-communicable

diseases (cardio-vascular, osteoporosis, etc.)

Risks of excessive vitamin intakes

- Hypervitaminosis – acute or chronic toxicity

Properties

• essential nutrients

Sources

• various foods of animal and plant origin

• absorption from plant sources is less efficient then from animal sources !!

the most relevant minerals: Ca, Fe, Cu, Zn, Se, Na, K, Mg, I, P

Function

• metabolism – part of enzyme systems

• components of body fluids

• building components of tissues

(e.g. bones, erythrocytes)

Minerals

http://www.paslabs.co.uk/wp-content/uploads/2017/06/Screen-Shot-2017-06-13-at-09.56.38.jpg

Minerals Function Sources

Calcium bone and teeth formation, blood clotting,

muscle contraction, function of nerves

dairy, broccoli, green leafy vegetables,

whole grains, soy, legumes, sardines

Phosphorus bone and teeth formation, metabolism, buffer

system, phosphate bonds

dairy products, meat, fish, eggs,

wholegrain products, vegetables, fruit

Magnesium metabolism, bone formation whole grains, leafy green vegetables,

nuts, soybeans, legumes, poultry

Sodium transmembrane potential, osmotic pressure,

water volume, ion in the extracellular fluid

salt, salt containing foods

Potassium transmembrane potential, essential ion in the

intracellular fluid

vegetables, bananas, prunes, meat, milk,

whole grains

Chlorine essential ion in the extracellular fluid, fluid and

electrolyte balance, aids in digestion

salt, salt containing foods, seafood

Sulphur component of amino acids, involved in

antioxidant defence

meat, fish, eggs, legumes, dairy products,

onions, cabbage, garlic, wheat germ

Iron transport of oxygen red meat, eggs, leafy green vegetables,

legumes, whole grains

Selenium antioxidant eggs, fish, whole grain products, legumes

Zinc component of enzymes, antioxidant, immunity meat, oysters, liver, eggs, soy, cheese,

legumes, cocoa, cereals

Copper cellular respiration, energy metabolism,

antioxidant, red blood cell formation

eggs, meat, liver, nuts, whole grain

products, cocoa

Fluorine prevention of dental caries, bone formation fluorinated salt, tea, sea fish

Iodine synthesis of thyroid hormones iodized salt, fish, seafood

Simple recommendation to supply

sufficient amount of vitamins:

...eat a variety of foods...

Current problems in nutritionDeveloped countries (Western and Central Europe, USA)

- food is availabile in more than adequate amounts

- overeating - excessive energy intake

- imbalanced of nutrient intake

Typical nutrient intake:

Excessive intake of

- fat, especially

saturated FA (animal fat)

- sugar

- sodium chloride (salt)

- alcohol

Inadequate intake of

- dietary fibre

- majority of vitamins

- many minerals

Many cases can be prevented.

Healthy diet can decrease the risk of health disorders !!!

Health consequences

- imbalanced diet and bad lifestyle increase the risk of serious diseases

- at present time - most serious and most frequent disease

- major health problem

Eat healthy diet !What is a healthy diet?

A healthy diet must supply

• all nutrients required for normal function of the body

• in adequate quantity

– lack but also excess of nutrients has adverse effects on the body

Healthy diet

- contains all different kinds of foods:

cereals, fats, vegetables, fruit, milk,

meat, legumes, nuts, fish, etc.

- is based on consumption of a variety of

foods within the basic food groups (e.g.

different kinds of fruit, vegetables,

legumes)

- colourful diet

Dietary recommendations

• Eat all different kinds of foods: cereals, fats, vegetables, fruit, milk, meat, legumes, nuts, fish, etc.

• Consume a variety of foods within the basic food groups (e.g. different kinds of fruit, vegetables, legumes)

• Increase daily intake of

– fruits and vegetables

• Increase daily intake of – milk and milk products, prefer the low fat products

• Choose fats wisely for good health.

– prefer plant oils rich in unsaturated fat

– limit animal fats rich in saturated fat and cholesterol (butter, lard)

– cut back on foods high in fat

- help to make a healthy food choice

- help to achieve balanced nutrient intake

Dietary recommendations

• Choose carbohydrate rich foods wisely for good health

– limit white cereals

– consume mostly wholegrain cereals rich in dietary fibre

– limit mono and disaccharides

• Choose and prepare foods with little or no salt

• Control calorie intake to manage body weight.

• regularly 3 – 6 times per day

• Consume adequate volume of beverages

– cut back on beverages high in calories and low in nutrition, such as soft

drinks

• If you drink alcoholic beverages, do so in moderation.

The food pyramid – A way how to eat healthy

Recommended daily amounts

- tables with recommended

daily intake of nutrients

- consider

- gender (male, female),

- age

- physical activity

- other factors

Food composition tables

- list the content of nutrients in individual foods

- usually values pre 100 g of food (sometimes per 1 portion)