NUTR 102x water

1)Water is the universal solvent for life, regardless of whether we are dealing with a minuscule single cell organism such as a bacteria or an entire human being. The cells in our body are made up mostly of water, with the exception of unique cells such as fat cells and bone cells. Nearly all of the tens of thousands of proteins in cells are dissolved in water. The function of all these proteins would come to an immediate halt if the water content dropped below a certain level and cells would dry out.

2)Water is the main component in blood and as such is responsible for the transport of many nutrients but also other molecules throughout the body. Nutrients such as glucose and amino acids are highly water soluble and are distributed across the body via the blood circulation. Fat soluble nutrients such as dietary fat and vitamin A are not soluble in water and as a consequence need to be wrapped in special particles called lipoproteins.

3)Water participates in numerous biochemical reactions in every cell. Many chemical reactions represent hydrolysis, which describes the breaking of a bond in a molecule via the insertion of water. An example is the digestion of dietary protein in the GI tract (see Nutrx101). In chemical terms, the cleavage of dietary protein into individual amino acids is only possible by the insertion of a water molecule into the peptide bond, breaking open the linkage between the two amino acids. Another example of hydrolysis is the cleavage of glycogen into glucose.

4)Water has a high heat capacity, which describes the amount of heat added as a ratio to the resulting temperature change. Basically, it takes a lot of heat (=energy) to raise the temperature of water by 1°C as compared to other solids or liquids. This property makes water an excellent buffer against large fluctuations in body temperature.

5)Water has a very important role in maintaining electrolyte balance in our bodies. This aspect is further explained in the section on sodium and potassium.

Water balance

Water balance is a balance between intake and loss.

Water intake - is not only through water. Other liquids and foods also contain water and contribute to the water intake. Fruits and vegetables are 80% water.

Average daily water intake is 2 Liters. The needed intake varies depending on climate, eating habits, weight and activity level of individual...

Most of our daily water loss occurs through urine. Urine is produced in the kidneys and stored in the bladder. The kidneys can adjust urine production in order to maintain water balance. The system will lead to the excess production of urine when fluid ingestion is high and overall water intake exceeds loss of water through the stools, lungs and skin. Conversely, the system will curtail urine production when water losses exceed water intake.

Water loss - through urine, sweat, breathing and stools. Excessive water loss leads to dehydration if not compensated by higher water intake.

Chronic diarrhea carries a risk of severe dehydration which can be life-threatening for infants and children.

Dehydration through sweat can occur in hot climate. Individuals engaging in physical activity in hot environment should pay attention to their fluid intake.

NUTR 102x Vitamines B

Folate

Folate is a generic term for a group of water-soluble B vitamins including folic acid and naturally occurring folates. All folates have same backbone but differ by presence of attachements: a methyl group and glutamate groups. Folate from the foods mostly have more than one glutamate group, which are removed during the digestion. Only folates with 1 glutamate group can be absorbed. They are transported to the target cells where they can donate or accept their methyl and glutamate parts. It's required to different vital processes: conversion of amino acids, production of blood cells, regulation of the activity of genes, or synthesis of new DNA during cell division.

Folate is found naturally in a wide variety of foods, including vegetables (especially dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, eggs, seafood, and grains. Spinach, liver, yeast, asparagus, and Brussels sprouts are among the foods with the highest levels of folate.

B12

Produced by bacteria. It's also produced in our intestine, but in insufficient amounts. In foods B12 occurs in free form or bound to the protein. Bound B12 released in stomach and absorbed in small intestine. 60% of B12 is stored in the liver.

Vitamin B12 is necessary for the formation of blood cells, nerve sheaths and various proteins. Vitamin B12 is also involved in fat and carbohydrate metabolism and is essential for growth.

B12 is presented in all animal products, and not in plant sources. Strict vegetarian should take B12 supplements or fortified foods.

NUTR 102x water-soluble vitamins

Vitamines B(all) and C are water-soluble vitamines.

Their primary functions are: energy releasing or blood cells forming.

The vitamines B are needed for healthly nerve conduction; they help us convert amino acids that make up protein. The B vitamins enable the transfer of methyl groups from one amino acid to another. It's also important in maintenance of our DNA. Vitamin B helps us with metabolisme of fats and amino acids into glucose. They take part in synthesis of hemoglobin and cholesterol, steroid hormones,

Vitamin C

Animals are able to synthesize C themselves from the sugars glucose and galactose, and hence do not require dietary vitamin C. However, humans, other primates and guinea pigs all depend on external sources to cover their C requirements. The absorption of vitamin depends on amount of vitamin eaten (100mg = ~80%absorbed; 2gr = ~50%absorbed). Unlike te fat soluble vitamins, the C have low storage capacity (300mg-2gr in the whole body). C is usually excreted via urine.

Functions:

- powerful antioxidant: C can donate electrons to harmful free radicals, what neutralizes them. Importantly, after that C can be re-activated. C protects water-soluble molecule against free radicals in the same way as vitamin E does for fat-soluble molecules.

- coenzyme: which means as part of an enzyme complex, vitamin C is required for the synthesis of collagen, the intercellulair ‘cement’ substance that gives structure to connective tissue in muscles, blood vessels, bones, tendons and ligaments.

Nowadays vitamin C deficiency is rare, but still occurs in people with a limited variety of foods in their diet. Obvious deficiency symptoms occur only if vitamin C intake falls below approximately 10-15 mg per day for many weeks. However, for optimal physiological functioning much higher amounts are required.

Sources: fruit and vegetables. Amount of C in products can be reduced by long storage and cooking. Many common foods contain little to no vitamin C. Milk and dairy, beans and legumes, Whole grains and meat contain very small or none C. A helthly diet that contains moderate amounts of raw fruit and vegetables provides sufficient amounts of C, thus no supplements are needed. Vitamin C has little to none correlation with preventing cold, heart attacks and any other deceases. Taking excessive amounts of C won't have benefits.

Vitamin C was the first observed vitamin as a magical component that prevented scurvy. In 1753, a Scottish naval surgeon named James Lind published his famous report of experiments he had made on ships of the British Navy, proving that oranges and lemons prevented or cured the disease. His classic studies are generally considered the first well described controlled trials in medicine.

The experiment involved 12 sailors with scurvy. Lind allocated two men to each of six different daily treatments for a period of fourteen days. The first group drank 1 quart of cider a day; the second group gargled with sulfuric acid; the third group had two spoons of vinegar 3 times a day; the fourth group drank half a pint of seawater; and the fifth group drank barley water. The sixth group ate two oranges and one lemon a day. He wrote in his report: "the most sudden and visible good effects were perceived from the use of the oranges and lemons; one of those who had taken them, being at the end of six days fit for duty".

NUTR 102x Week1: fat soluble vitamins: A, D, E, K.

Vitamins are small organic molecules that needed in small quantities for good growth, metabolism and health.

Fat soluble vitamins: A D E K.

Water soluble vitamins: all B and C.

Fat soluble vitamins are in fats, and we absorb them with the fat molecules. The fat soluble vitamins cannot leave the body with the urine (like WS vitamins), and surplus is stored in liver and fat tissues. FSV can be eaten once in a while, because they tend to be stored in the body, whereas you need to take WSV every 1-3 days. OVERDOSE of FSV can be toxic, while extra WSV can simply leave the body.

Vitamin A

Vitamin A is the generic term for a family of fat-soluble compounds related to retinol. It's found in animal sources (as a pre-formed rethinol), or in plant sources in form of Beta-carotene (contains in yellow, orange or red veggie).

Rethinol stored mainly in the liver, in stellate cells (high in fat). The provitamin A carotenoids can be also digested and taken up as a Rethinol molecules, but not as effective as a rethinol from animal sources.

Functions:

• Promoting vision

• Participating in protein synthesis and cell differentiation (and thereby maintaining the health of epithelial tissues and skin)

• Supporting reproduction, growth and immune system functioning
Sources:

The richest food source of preformed vitamin A is liver. Considerable amounts are also found in fish oils, egg yolk, whole milk, butter and cheese. Provitamin A carotenoids are found in carrots, yellow and dark green leafy vegetables (e.g. spinach, broccoli), pumpkin, apricots and melon.

Vitamin D

Vitamin D can actually be synthesized in the human body, but may be necessary in the diets of people who don't get enough sun exposure to make their own vitamin D. Unlike many other vitamins, Vitamin D is present in only a limited number of foods.

The main dietary forms are vitamin D2 and D3, but to be biologically active they first have to be converted in the liver and then in the kidney. Vitamin D3 is synthesized in the skin by the action of ultraviolet light on 7-dehydrocholesterol, a cholesterol derivative.

Vitamin D is activated via two steps. Calcitriol is the active form of vitamin D that is responsible for the physiological effects of vitamin D. The formation of calcitriol is strictly controlled according to the body’s needs.

The classic role of vitamin D is to regulate calcium and phosphorus metabolism.

Vitamin E

The importance of vitamin E in humans was not accepted until fairly recently. More recent studies have shown that vitamin E also has roles in cell signaling, regulation of genes, inhibition of cell proliferation, and platelet aggregation. Vitamin E is an antioxidant. depletion of vitamin E tissue stores takes a very long time.

Main source of vitamin E is vegetable oils, nuts and wheat germ.

Vitamin K

Compared to other fat-soluble vitamins, the total body pool of vitamin K is small and turnover of vitamin K is rapid. The body recycles vitamin K in a process called the vitamin K cycle, allowing the vitamin to be re-used many times.

Vitamin K is essential for the formation of biologically active forms of a range of proteins. These proteins regulate blood clotting and are essential for bone health.

Vitamin K deficiency is uncommon in healthy adults but occurs in individuals with gastrointestinal disorders, fat malabsorption, liver disease...

The most common sources of vitamin K are spinach, broccoli, iceberg lettuce, and fats and oils, particularly soybean and canola oils.

Week 7: energy balance

energy balance = energy in and energy out. Can be positive (gaining weight) and negative (losing weight).

Food can be high satiating(vegetables) and low satiating(soda). People in general have pretty good sence of energy balance. However, eating non-satiating food can lead to weight gain. The factors that lead to overeating:

-Social environment (like family gatherings)

-sensory factor (appealing and tasty food with high calorie)

-stress (some lose appetite, some gain)

There are two kinds of psychological self-regulation: short-term(GI tract sends signals to the brain if satiated and full), long term(coming from adipose tissue). fat tissue sends hormone Leptin. Concentration of leptine in blood is dependent on bodyfat %. Based on the leptine lvl the brain makes long-term adjustment of hunger to maintain certain lvl of bodyfat. The same system have all animals, it’s a survival technique. However, in many humans their BF% gets higher with aging. Unhealthly habits are stronger than instincts, and throw off the BF% what leads to deceases.

Our expenditure are made up from 3 parts: maintenance, physicl activity and growth(only children and pregnant women).

BMR is the energy needed for maintenance. We spend about 10% of our food intake for digestion and absorption and it’s also calculated in BMR (solely to digest 1000cal meal you need 100cal). BMR highly depends on dody lean mass, thus your height, weight and muscularity.

PAL(phys. activity lvl) represents amount of energy spent to perform activities. It varies a lot, from 200cal a day in sedentary individuals to 2000cal in competetive athletes. Most people with moderate activity have PAL 1.6-1.7. (it means during the day they spend their BMR*1.6).

PAR (phys. activity ratio) represents energy cost of activity expressed as a multiple of BMR. For lying, sitting, watching a TV it’s around 1.0-1.4. PAR for walking is 4 (1h of walking burns 4 times more calories than 1h of lying). For some excercises PAR can exceed 10.

Weight gain and loss: these processes are not linear!

For example: person A decides to eat at a 300cal surplus. They will experience rapid weight gain that will gradually slow down and stop. Why’s that? Because when person A gain weight their energy expenditure also increases, because he is more heavy and need more energy to live. The same goes for weight-loss. If you are leaner, you’ll need to cut more and more calories to lose weight.

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Это была моя последняя лекция с первого курса, надеюсь вас это заинтересовало, хотя сейчас, просматривая свои лекции, я понимаю что для человека который не слушал курс они малоинформативны :)

Сегодня начал свой второй курс из трёх, пока ничего не сделал. Я достаточно рад этим курсам, для тех, кто интересуется более глубоким и непредвзятым взглядом на диетологию я горячо рекомендую этот курс.

Завершил свой первый курс из трёх.

Скорее всего я откажусь от курса health and wellness, они только что выпустили первую неделю. Просто ужасно.

Между тем, я чрезвычайно доволен основной серией из 3х курсов от другого университета. До конца этой недели перепрочитаю свои конспекты и сдам финальный экзамен. После этого я вознагражу себя десертами и алкоголем за полученые знания в области здорового питания, допройду все бонусные элементы, и перейду на второй курс.

Week 6: Proteins

20 different amino acids distinguished into 9 essential (have to be in our diet) and 11 non-essential.

Amina acids are linked together in protein chain or poly-peptides.

Excellent protein sources are meat, fish, eggs, and dairy products.

Digestion: starts into the stomach where high acidity unfolds protein chain giving easy access to it to enzymes. Enzymes break protein chains into individual amino acids that can be absorbed. Once absorbed these amno acids used by our body for making body proteins that are needed for functioning.

Functions of protein:

1.Building material. the most important is COLLAGEN.

2.Enzymes are proteins, and are used everywhere in the body as catalysts of chemical processes.

3.Transporters

4.Hormones are messengers between organs that travels through the blood. I.e. insulin released by pancreas and travels to muscle and fat tissue to promote glucose uptake.

5.Antibodies, or immunoglobulins

6.regulation of fluid balance.

PROTEIN TURNOVER and nitrogen balance

= continuous process of synthesis and degradation of protein in the body.

In 1 year all the protein (entire body) got replaced.

Protein comes into the body from the food. Protein leaves the body by breaking into nitrogen (urea) and carbon (used as fuel).

Limiting amino acids: for proper protein synthesis all essential amino acids should be presented in adequate quantities. The limiting amino acid is the most abundant in a diet, hinders all process of synthesis.

The quality of protein depends on: digestibility and amino acids composition. Animal foods have better protein quality than vegetable sources. Combining beans and grains gives you good protein composition.

Week4: digestion and metabolism of lipides

triglycerid -> breaking down to 2 fatty acids and 1 fatty acids attached to the molecule of glyceride. Made mostly by enzime PANCREATIC LIPAZE and remainder by GASTRIC LIPAZE.

Important in dig. are BILE ACIDS, they emulsify (break down in small pieces fats) so it’s easier to digest them. It’s produced by the liver from cholesterol and stored in gallblader. When fat enters system, it causes the secretion of hormone cholecystokinin (CCK). This hormone triigers the gallblader to contract and send bile acids into the duodenum. Later bile acids forms from single fatty acids special structure called micelles, which is easy to absorb.

Absorbed fatty acids are converted back into tryglicerides by the enterocyte, the intestinal cell. This process called re-esterification. These tryglicerides are packed into particle called CHYLOMICRONS, in which it travels through the body in the bloodstream. (Fat is wrapped into protein, what enables it to travelo into the blood.

Metaboloism!

After a meal: our body produces large numbers of chylomicrons that are released into bloodstream. Then they got caught by enzyme LIPOPROTEIN LIPAZE on the wall of cappilar and get absorbed. Two tissues can absobb fat: muscles (for energy) and adipose tissue (for store excess).

Cholesterol can’t be absorbed by tissues and ends up in liver.

In fasted state the fat got released into blood from storages.

Cholesterol: needed to make bile acids that are used to digest fats, to produce male and female sex hormones, and it’s part of cell membranes. Our body produces its own cholesterol, and only 1/3 of cholesterol is coming from diet. So you can completely devoid cholesterols from diet.

Week5: lipids and cardioviscular health

The most commom form of heart disease is coronary (ischemic) heart disease: the blood vessels going to the heart become narrow and rigid, restricting blood flow to the heart. Stroke: arteries to the brain are blocked.

Cardioviscular diceases are linked to the ATHEROSCLEROSIS: build a plaque on arteria wall, narrowing it.

Cholesterol: LDL (bad): transport chol. to the tissues that need it, HDL (good): carry exceed chol. back to the liver from blood and tissues.

Week 5: Dietary lipids

Cholesterol: different people have different abilities to absorb dietary chol. (30-80% of intake). So the response varies as well.

Saturated and unsaturated fats: reducing part of saturated fats and elevating part on unsaturated fats leads to lower blood LDL and reduces CHD risk.

Trans fatty acids: lead to cancer, diabetes (doubtful) and CHD (proven).

Omega3: more precisely n-3 PUFA (fish oils) reduce blood trygliceride level.

General guidelines:

-limit fat intake to 30-35% of total energy intake

-limit saturated fat intake to 10% of total energy intake

-replace solid oils with liquid ones

-reduce trans fat consuming as much as possible

-eat fewer than 300 mg of cholesterol per day

-eat fish at least once a week

Week4: chemistry of lipides

Three types:

-triglycerides (about 95% of all fats in diet)

-phospholipids

-sterols

triglyderides = three fatty acids connected by a glicerol molecule.

three main properties of fatty acids:

-chain length (usually 16-18 carbon atoms)

-how unsaturated it is (more double bonds -> more unsaturated fat is)

-point of saturation (where double bonds are)

c18:2N6 ->fatty acid with 18 carbon molecules, 2 double bonds and 1^st double bond is 6^th from the methyl

Two main fatty acids consumed (66% of all):

-Oleic

-Palmitic

The firmness of the fat is determined by the type of fatty acids: Shorter-chain and more unsaturated fat is -> lower melting point.

Vegetable oils contain mostly unsaturated FA -> liquid at room t

Butter contains mostly saturated FA -> solid at room t

saturated FA is less prone to oxidation, and it’s bad.

HYDROGENATION – turning unsatur. FA into saturated. Producers do this procedure to make oils more stable. Along the way it produces the trans FA which are bad for health. (you can’t produce trans FA during regular cooking).

Phospholipids = component of all cell membranes and thus presented in small quantities in all foods. Used as an emulsifier in food industry.

Sterols = plant sterols and cholesterol (which presented ONLY in animal foods). Plant sterols leave the body with the stools and can be taken with cholesterol to reduce cholesterol absorbtion (by taking you can achieve maximal reducing of blood chol. lvl is -10%, not more).

cooking oils = 100% fat

butter and mayo = 80% fat

bacon and some sausages = 40% fat

Cholesterol only in animals food, most in butter, cream, cheese, egg yolks.