Nutrition 1 - Macro Nutrients Flashcards
Carbohydrates; groups
The preferred source of energy by the body. Includes starches (bread, pasta etc), cellulose (plant fibre), and sugars.
Three main categories:
1. Single sugars (monosaccharides)
2. Double sugars (disaccharides)
3. Complex carbohydrates (polysaccharides)
Carbohydrates:
1. Single sugars (monosaccharides)
Single sugars (monosaccharides):
* Glucose (key energy source)
* Fructose – fruit sugar
* Galactose – milk sugar
Carbohydrates:
2. Double sugars
(disaccharides
Double sugars (disaccharides)
Sucrose – sugarcane (glucose + fructose)
Lactose – milk sugar (glucose + galactose)
Maltose – brains (barley) (glucose + glucose)
Carbohydrates:
3. Complex carbohydrates (polysaccharides)
Complex carbohydrates (polysaccharides)
* Starches – found in foods such as bread, rice, pasta (grains), vegetables, legumes etc
* Cellulose – the structural material plants (found in plant walls) and provides dietary fibre
* Complex carbohydrates:
o Retain their rich nutrients
o Are digestive more slowly, promoting satiety and help to keep blood glucose in balance
Refined carbohydrates
Refined carbohydrates (e.g. sweets, white bread) are carbohydrate that have been processed & stripped of their important nutrients. These lead to:
* A lack of nourishment
* Tooth decay
* Lower energy levels/fatigue
* Blood sugar imbalances
* Insulin resistance and type II diabetes
* Weight gain, obesity
* A weakened immune system; they deplete cells of vitamins C
* Poor bowel health and constipation (due to lack of fibre)
Therefore you should focus on complex carbohydrates
Carbohydrates: unrefined carbohydrates list
Unrefined/wholegrain – complex carbohydrates:
* Wheat, rice, oats, barley, rye, millet, buckwheat, spelt, kamut, quinoa, teff
* Whole – bread, pasta, noodles
* Legumes, beans, lentils, peas, nuts, seeds
* Vegetables, fruit
* Honey (some) e.g. manuka, raw (unpasteurized) honey
Carbohydrates: refined carbohydrates list
Refined Carbohydrates stripped of most nutrients:
* White – cereals, flours, rice, barley
* White – b read, pasta, noodles
* Pastries, cakes, biscuits, sweets
* Chocolate, crisps, pizza
* Fizzy drinks, sugar, honey, jam
Fibre
Fibre is a complex carbohydrate that originates from plant cell walls that cannot be digestive by the human.
Benefits:
* Aids the movement of food through the digestive tract, increase stool bulk – prevents constipation
* Lowers the risk of diverticulitis and colon cancer
* Reduces absorption of dietary cholesterol and slows glucose absorption (preventing spikes in insulin)
* Reduces the risk of cardiovascular disease / type II diabetes
* Weight control–fibre increases satiety– Feel fuller for longer
* Feed the microflora, resulting in numerous health benefits (fermentation of some fibre in colon by healthy bacteria produce short chain fatty acids = fuel source for colon cells, reduces inflammation, effects throughout whole body such as blood glucose control, cholesterol moderation)
Soluble fibre
Soluble fibre dissolves in water. (also referred to as fermentable fibre – produce short chain fatty acids)
* Attracts water in the body to form a gel
* Slows digestions and regulate blood sugar (reduces absorption of dietary cholesterol)
* Has a filling (satiating) effect
Good sources includes: oats, legumes, apples, oranges, pears, strawberries, nuts, flaxseed, psyllium, cucumbers, celery, carrots
Insoluble fibre
Insoluble fibre does not dissolve in water
* Helps move waste through the intestines, encouraging regular bowel movements
Good sources include: whole grains, bran, seeds, nuts, carrots, cucumber, cabbage, onion, courgette, celery, dark leafy greens
Proteins: Function
Proteins are formed of amino acids, which act as the building blocks for proteins. Proteins function to:
* Provide body tissue structure e.g. in skin, bones, blood vessels, hair
* Provide movement (e.g. muscles)
* Carry substances (e.g. haem meoglobin – oxygen)
* Act as enzymes (e.g. digestive enzymes)
* Form hormones (e.g. insulin)
* Provided immune defense (e.g. antibodies)
* Provide alternative energy source (less efficient than carb/fats)
Protein in Greek = ‘or first importance’
Amino acids
Proteins are formed of amino acids, which act as the building blocks for proteins. The human body commonly uses 20 amino acids. Amino acids (AAs) are divided into:
1. Non-essential amino acids: produced by the body, not required in the diet
2. Essential amino acids (nine of them): not produced by the body, must be in the diet
3. Conditionally essential amino acids: some non-essential AAs become conditionally essential in certain circumstances, e.g. at certain ages or during diseases
The essential amino acids are: histadine, leucine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
Proteins: complete
Complete protein:
* Food that contains all nine essential amino acids (AAs)
Proteins: incomplete protein
Incomplete protein:
* Food low in one or more of the essential AAs
* Most plants foods have an incomplete protein profile – one or more essential AAs are missing (commonly either methiomine or lysine)
* A varied vegan diet delivers all necessary AAs. The quality/digestibility of protein from food is more important than the amount of protein eaten
Plant proteins (complete)
Plant proteins are affordable, delicious and easy to obtain from vegan food. They also have additional nutritional value such as fibre and phytonutrients.
* When properly prepared they are easily utilised by the body
* Associated with decreased risk of many chronic conditions
Examples of vegan foods containing all nine essential AAs:
* Quinoa – gluten-free and versatile
* Buckwheat – not actually wheat
* Pumpkin seeds
* Chia seeds
Plant proteins (incomplete
Many plants proteins are incomplete proteins. This can be easily remedied by complaining protein foods that compliment each other.
* Each food contains the essential AAs the other food is lacking, e.g. rice is low in lysine, that beans contain good amounts of lysine
Combine:
* Legumes with nuts/ seeds
* Whole grains with nuts/ seeds
* Whole grains with legumes
* Spirulina with grains, nuts, seeds
Plant proteins: soy
Soy:
* Many soy products are highly processed; unless organic may contain genetically-modified story
* Soy contains compounds such as agglutinin (lectins that can cause leaky gut/ inflammation – eliminated during heat/fermentation), trypsin (protein digestion) inhibitors and a-amylase (carbohydrate digestion) inhibiting factors that make it difficult to digest
Animal proteins
Includes the protein found in meat, poultry, eggs, dairy, fish
Positives:
* Contains all the essential amino acids
Negatives:
* The amino acids abundant in animal proteins (e.g. methionine) are sulphur-base, which can form sulphuric acid in the body. This can create an acidic, pro-inflammatory environment. Eat small amounts
* Meat can be difficult to digests and requires a lot of energy
* Unless organic, can contain chemical residues. Occurs either by direct oral or topical dosing of the animal (e.g. pesticides to control lice and fleas) or exposure to crop pesticides in feed
Lipids: fats and oils
Lipids:
* Lipids are insoluble in water and soluble in alcohol (consider what happens when oil mixes with water)
* They are an important component of cells (e.g. cell membranes)
* Lipids include fats, oils, waxes, steroids and fatty acids
* Eating too much fat, or the wrong type of fat, can lead to weight gain
However including lipids in the diet is essential to health
Lipos = greek for fat
Lipids: Functions
- Energy production and storage: the most concentrated form of energy
- Insulation and protection: protects and insulates organs, nerves and bones. Needed for cell membranes
- Digestion and absorption: carries fat soluble vitamins; A, D, E, K. Needed for bile production in the liver.
- Hormone production: cholesterol is a lipid needed to produce important hormones in the body (oestrogens, progesterone, androgens, cortisol etc)
Fatty acid
Fatty acids are the building blocks of fats in the body and the food we eat.
* During digestion, the body breaks down fats into fatty acids, which can then be absorbed into the blood.
* There are three types of fatty acids:
1. Saturated fatty acids: e.g. coconut oil and butter
2. Polyunsaturated fatty acids: Omega 3 and 6
3. Monounsaturated fatty acids: Omega 7 and 9
* Omega-3 and 6 essential fatty acids (EFAs) and cannot be made by the body. They are essential to health and must be obtained from diet
Monounsaturated = one double bond, Polyunsaturated = many double bonds (The more bonds, the less stable – more prone to oxidations).
Unsaturated –Liquid at room temperature
Fats
The degree of saturation refers to the number of hydrogen molecules within a fatty acid.
- Fatty acids fully loaded with hydrogen atoms are ‘saturated fatty acids’. Those that have hydrogen atoms is missing (and hence have doubled bonds in the fatty acid chain) are ‘unsaturated’.
- Saturated fatty acids (e.g. coconut oil) are solid at room temperature; unsaturated fatty acids (e.g. olive oil) are liquid.
- The presence of double bonds in a fatty acid makes it more susceptible to oxidation, so saturated fats are less likely to oxidise, and unsaturated fats more. Coconut oil is more stable to cook with at higher temperatures than e.g. in sesame oil
- Fat-soluble antioxidant e.g. vitamin E are important when including fats and the diet
Saturated fats
Saturated fats:
- Founded animal products such as milk, cheese, meat and in tropical oils such as coconut palm oil.
- Saturated fats are linked to increased LDL-cholesterol (risk of heart disease). However sugar plays a much greater role in contributing to heart disease
- Also linked with increased inflammation
- Be aware of excessive saturated fat intake
Saturated fats: coconut oil
Coconut oil is high in saturated fat, but the fats are medium-chain triglycerides (MCTs)
* MCTs are metabolised differently to most dietary fats, which long-chain triglycerides
MCTs in coconut oil are:
* Digested more easily
* Transported directly to the liver where they are readily converted to energy rather than stored as fat
* Converted to ketones– compounds that can be used for energy by cells neurons in the brain
* Antimicrobial/antifungal
Fats: good fats
Good fats are those high in omega-3, 6 and 9
Sources of omega-3 include:
* Cold water oily fish – SMASH = salmon, mackerel, anchovies, sardines, herring
* Flaxseed, chia seeds, hemp seeds, walnuts
Sources of omega-6 include:
* Safflower, sunflower, nuts (other than walnuts), meat, dairy, eggs, borage oil, evening primrose oil, vegetable oils
Sources of omega-9 include:
* Olive oil, avocados, almonds, Brazil nuts, pecans, macadamia
EFA deficiency (omega-3 and 6)
Signs of EFA deficiency
- Dry eyes, skin and hair
- Painful joints (inflammation)
- Hormonal problems
- Inflammation
- Slow cognition
- Recurrent infections
- Low metabolic rate and weight gain
Omega-3 and 6: balance
Omega-6 is more abundant in the modern diet.
- Many people consume much more omega-6 then omega-3 (average ratio = 16:1, ideal = 5:1 or less)
- Excessive omega-6 can inhibit conversion of omega-3 to the active components EPA and DHA
- Furthermore, it can increase production of arachidonic acid (AA)
- While AA has some important functions in the body, it also promotes inflammation. So an omega-6 abundant diet promotes inflammation body
Hydrogenation
Hydrogenation describes the chemical saturation of unsaturated fats
- It involves reacting the oil with hydrogen gas using a catalyst such as nickel
- The process creates trans-fats
- The purpose is to harden the fat, prevent rancidity in foods and increase the shelf-life
- Trans-fats can also be formed by heating to high temperatures, or heating oil repeatedly (this causes the fat to become more solid)
- Health professionals warn that trans-fats are dangerous. They should be banned – that is NO safe level!
Trans-fats
Effects on health:
* Increase risk of heart disease
* Increased risk of blood clots forming
* Trans-fats ‘stiffen’ cell membranes, making them prone to oxidative damage and making cell membranes leaky
Sources include:
* Refined vegetable oils, fried, processed, fast food; frozen dinners, margarines, peanut butter, ice cream, cakes, biscuits, pastries and crisps
Healthy fats: food sources
Fruit: avocado, olives
Seeds: chia, flax, sunflower, pumpkin, hemp, seed butters
Seed oils: flax, chia, hemp, sunflower, olive Oil –ensure oils are cold pressed
Nuts: almonds, Cashews, Brazil nuts, walnuts, nut butter
Other: organic raw dairy, coconut
Oily fish: salmon, mackerel, sardines, anchovies
Water: functions
Water is an essential nutrient that makes up 70% of the human body
Functions:
* Regulates body temperature
* Transports nutrients to cells via the bloodstream
* Removes wastes (e.g. sweat, urine)
* Supports joints/cartilage health and nourishment
* Needed for digestion (e.g. bile, saliva), absorption, circulation and excretion
Water: intake
Recommended fluid intake is 1.5 to 2 Litres per day
- In some situations more water is needed e.g. exercise, hotter climate, fever
- On average, food intake contributes 20% of daily water intake
- Avoid caffeinated, carbonated and sugary drinks. They deplete the body of nutrients and can disrupt blood glucose levels.
- Avoid drinking with meals as it dilutes digestive enzymes, impairing digestive function
Symptoms of dehydration
- Muscle and joint pain
- Fatigue
- Headaches
- Back pain
- Constipation
- Dry skin
- Yellow urine with a strong odour
- Lack of urination
- Weight gain – thirst is often mistaken for hunger!
