Dietary guidelines : Protein

Protein is a basic building block of humans. Amino acids are the basic building block of protein.

Protein can also serve as a fuel source.

Protein is second to water as most common element of human body.

Proteins are molecules consisting of one or more long chains of amino acid called polypepetides. Proteins differ from one another in their sequence of amino acids.

Proteins are important in the structure (building and maintaining) and the functioning of all cells.

Protein is a major component of all cells especially muscle, hair and skin.

Protein is needed for all biochemical reactions in the human body.

Once formed, proteins only exist for a certain period of time and are then degraded and recycled by the cell's machinery through the process of protein turnover. A protein's lifespan is measured in terms of its half-life and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells.

There are 20 amino acids in the human body.

Nine are essential amino acids (They cannot be synthesized by the body). phenylalanine, valine, threonine, trytophan, methionine, leucine, isoleucine, lysine and histidine.                                                                                                        

There are five amino acids which humans are able to synthesize in the body. alanine, aspartate, asparagine, glutamine and serine

There are six conditionally essential amino acids which the body is able to synthesis under certain conditions.

arginine, cysteine, glycine, glutamine, proline and tyrosine.

Sources of protein.

Meat, dairy products, eggs, fish, legumes (peas, beans and lentils) are sources of complete protein.

Whole grains and cereals.  Have limited of lysine or threonine. Whole grains and cereals with a concentration greater than 7.0% of amino acids, are buckwheat, oats, rye, millet, maize, rice, wheat, sorghum, amaranth, and quinoa.

Foods with protein concentrations greater than 7.0% percent are nuts, pumpkin seeds, hemp seeds, sesame seeds, and sunflower seeds.

Vegetables are poor sources of protein. The protein content of yams,  cassava and sweet potato is between 0 and 2 percent.

Fruits are a poor source of amino acids.

Legumes, cereals, nuts and seeds, and animal protein contain different proportions of all amino acids especially lysine, threonine and tryptophane.

No food is complete protein. Most foods containing protein also contain carbohydrates, oil, fibre, vitamins and minerals.

No food is the complete protein. The best source of protein is often a combination of various foods, because different foods are rich in different amino acids.

Digestion

Digestion involves breaking down peptides containing multiple amino acids into peptides containing 1, 2, 3 or 4 amino acids.  Digestion involves hydrochloric acid and enzymes present in the gastro-intestinal tract.

Absorption rates depend on type of protein.

Dietary requirement of protein depends on:

Body weight

Rate of growth and development (during childhood increased need of protein)

Physical activity

Carbohydrate intake

Pregnancy or breastfeeding

Presence of illness or injury

Recovering from malnutrition, trauma or an operation

Adult women need 46gm/day

Adult men need 56gm/day

Based on weight of 57 kg female and 70 kg male and 0.8 gm/kg and a sedentary lifestyle.

Active people need 1.6gm/kg-1.8gm/kg

Dietary guidelines : Carbohydrates

What are the different types of carbohydrate?

Simple carbohydrates

Monosaccharides: Glucose and fructose (fruit and vegetables), galactose (milk), xylose (found in wood and cellulose of some plants)

Disaccharides: sucrose (table sugar), lactose (milk), maltose (from starch), trehalose (often added to ice-cream)

Sucrose (disaccharide) consists of glucose and fructose.

Lactose (disaccharide) consists of glucose and galactose

Simple carbohydrates are sugars. They consist of just one or two molecules. They provide a rapid source of energy, but you soon feel hungry again.

Foods containing lots of simple carbohydrates are white bread, lollies, and cakes.

Complex carbohydrates

Oligosaccharides: maltodextrins (produced from starch and used as a food additive).

Polysaccharides: starch present in potato, maize, rice other cereals, cellulose,

Starch is the storage form of glucose found in plants.

Complex carbohydrates consist of long chains of sugar molecules.

Complex carbs are wholegrains and foods that still have their fiber. They tend to fill you up for longer, and they are considered more healthful, as they contain more vitamins, minerals, and fiber.

Starches consist of those glucose molecules, joined together in large clusters. Still-larger arrays of glucose molecules make up indigestible dietary fiber, molecules of cellulose or hemicellulose. The atomic bonds in cellulose molecules are so strong that your stomach can't break them down. Starches are less stubborn and can be digested to some degree but not always completely.

There is another way of classifying carbohydrates:

Bad carbs

Bad carbs are sucrose (table sugar) and refined wheat.

Healthy carbs  

Fruits, vegetables, legumes, dairy milk, cheese and yogurt, nuts and seeds.

Whole grain such as wheat, rye, barley, rice, quinoa, amaranth, buckwheat, millet, maize, sorghum and oats. 

Most of these foods also contain protein, oil, fibre, vitamins and minerals, , phytonutrients.

How many carbohydrates are needed each day?

Women need 1,600-2,400 calories per day.

Men need 2,000-3,000 calories per day.

Experts have said adults should consume 45-65% of calorie intake as carbohydrates. With only 10% from sugars.

The brain needs carbohydrates, specifically glucose, because neurons cannot burn fat

Athletes need more carbs to replace glycogen used during exercise. Up to 70%

Calculate 45-65% of your daily calorie intake and then divide by four to get grams of carbs.

For example:

2,000 calorie diet

900-1300 calories from carbs

225-325 grams of carbs

Does cooking or processing alter the carb?

When eating starch (polysaccharides) alpha-amylase break down the starch to glucose which is then absorbed. Starch varies. There are different types. The amount of glucose absorbed varies.  If it is cooked more is absorbed. If it contains fiber less is absorbed. If the fruit is riper more is absorbed. If the grain is turned into flour more is absorbed.

When cooked starch molecules undergo gelation. They absorb steam from their own moisture or the cooking liquid, swell and then burst. They are then more digestible.

Raw starches are not as easily absorbed. They travel further down the colon where they encounter anaerobic bacteria.  These bacteria breakdown some of the carbs and cause flatulence. Some bacteria will pass undigested through the intestine.  Some of the carbs are absorbed further down the intestine.

Resistant starch isn’t absorbed on its passage through your colon. It feeds some bacteria in your intestine which is a good thing. It provides all of fiber’s benefits.

Processing starch

Whole grains are often milled into flour. If the flour is sifted then fibre, protein, oil, vitamins, minerals and phytonutrients are often discarded decreasing its nutritional value.

The advantage of processing whole grain wheat to make plain white flour is the bread or cakes made will be lighter and fluffier. The disadvantage is they will not be as healthy.

Whole grain flakes are readily available.

How can carbohydrates lead to diabetes?

Eat carbohydrate.

The digestive system breaks down the complex carbs to glucose.

Glucose is absorbed enters the blood stream. (Blood sugar increases).

Beta cells in pancreas release insulin.

Insulin lowers the blood sugar level by making cells absorb glucose for energy.

When blood sugar drops to a low level alpha cells in pancreas release glucagon.

Glucagon makes liver release glycogen releasing glucose needed by the brain.

If you eat too much carbohydrate.

Blood glucose increases rapidly.

Cells need more insulin to react. This is insulin resistance.

Pancreas has to produce more insulin. Eventually it wears out and can cease altogether.

The glycemic index

Carbohydrates enter the bloodstream as glucose at different rates.

Carbohydrates that raise blood sugar quickly are said to be high on the glycemic index.

High-GI carbs enter the bloodstream quickly as glucose.

Carbohydrates that have a gentle effect on blood sugar levels have a lower GI score.

Low-GI carbs take longer to digest and break down and enter the blood stream.

Low GI foods: whole grains, fruit, vegetables, legumes

The Bottom Line

I will attempt to eat natural, unprocessed, unrefined carbs such as wholegrains, legumes, vegetables and fruit.  

I will attempt to avoid refined carbs such as table sugar and white flour. 

No fruit juice. If I want orange juice I will eat an orange.

I will cook plants to make the food more palatable. Cooking is not a big negative or positive.

Dietary guidelines : The perfect diet

I want to find the perfect diet.  That’s impossible

Okay, well maybe but I want a few dietary guidelines?

I will break down diet into different areas.  

Carbohydrates

What are the different types of carbohydrate?

How many carbohydrates are needed each day? Does it vary in different people?

I look at carbohydrates in grains, fruit or vegetables.  Carbohydrates are high in processed foods.

The grains are wheat, rye, barley, rice, quinoa, amaranth, buckwheat, maize and oats.

How much does the processing alter the grain? What is a refined carbohydrate?

Cooking: which foods need cooking?

When we eat a carbohydrate what else are we eating? Fibre, vitamins and minerals, protein, oil

Protein

What are the different types of protein?

How much protein do we need each day? Does it vary in different people?

Animal protein: meat, fish, eggs

Dairy protein: yoghurt, cheese, milk

Legumes: beans, peas, lentils

When we eat a protein what else are we eating? Carbohydrates, oil, vitamins and minerals

Dietary rules: vegan, vegetarian what effect do they have?

Oils and Fats

What are the different types of fats and oils?

How much oil do we need each day? Does it vary in different people?

What is the difference between fat and oil?

Animal fat

Fish oil

Plant oils: olive oil, canola oil, avocado, nuts, seeds

Saturated fats:

Unsaturated fats: polyunsaturated fats, monounsaturated fats, omega-3, omega-6

Healthy fats, unhealthy fats

Liquids

How much liquid do you need each day?

How do drinks vary?

Tea

Coffee

Alcohol

Kombucha  and other fermented drinks

Vitamins and minerals

What are the supplements?

What supplements are needed every day?

Are different supplements needed by different people?

Salt:  How important is it?

Fibre

What are the different types of fibre?

What does fibre do in the body?

What foods contain fibre?

Omega-3 : Many thanks to the ABC who printed the original

Omega-3: What are the health benefits and how should you eat it?

Omega-3. You've seen the word (and number) splashed across cereal boxes, tins of tuna and one of Australia's most popular supplements: fish oil.

These famous fatty acids are thought to have a vast range of health benefits.

So how can you make the most of them?

Omega-3 is short for omega-3 polyunsaturated fatty acids. They're a family of "essential fats" that play an important role in the way our cell membranes work.

Fats tend to get a bad rap, but polyunsaturated fats are the good guys. They help keep cholesterol balance in your body, decreasing the bad cholesterol and increasing the good cholesterol.

When it comes to the health benefits of omega-3, here's what you need to know.

The strongest evidence for the benefits of omega-3 fats comes from studies of heart disease.

Research shows people who regularly consume fish (the best source of omega-3) tend to have lower rates of heart disease and stroke — and that may well be down to omega-3.

These fats are known to help lower your heart rate, reduce the risk of clotting, lower triglycerides, decrease blood pressure, improve blood vessel function and delay the build-up of plaque in coronary arteries.

"Omega-3 fatty acids cut down the blood fat — blood cholesterol and blood triglycerides — and they also cut down inflammation in the body. These are the two underlying causes of cardiovascular disease," Professor Garg says.

Those anti-inflammatory properties of omega-3 have been used to help people with rheumatoid arthritis and diabetes.

High-fish diet recommended

While omega-3 fats can be found in plants, seafood, and to a lesser extent, eggs and meat, the best way to boost your intake of fatty acids is to increase the amount of oily fish you consume.

The Heart Foundation recommends including two to three serves of fish (with the skin on) in your diet each week (150 grams per serve), as well as one gram of plant-sourced omega-3 fats each day.

"When eating or preparing fish, choose cooking methods such as steaming, grilling, light pan-frying, baking, barbequing or even raw fish such as sushi or sashimi," the Heart Foundation says.

"You can add fish to stir-fries, casseroles, pasta and soups, or simply have it in a sandwich or in a salad."

Good sources of marine omega-3s include salmon, blue-eye trevalla, blue mackerel, herring, canned sardines, canned salmon and some varieties of canned tuna.

When it comes to plant sources, walnuts, linseed, chia seeds, pumpkin seeds, tofu, leafy greens and vegetable oils such as canola and soybean are all good options.

Vegetarian alternatives on the horizon

If you don't eat fish, it's important to maximise your intake of plant-based sources of omega-3.

However, the type of omega-3 fatty acid found in plants (alpha-linolenic acid) is nowhere near as effective as the types found in marine sources (docosahexaenoic acid and eicosapentaenoic acid).

"From the plant sources, we do not get the fatty acids which are present in our body — we only get the precursors of those omega-3 fatty acids," Professor Garg says.

"So, they're not readymade … our body has to work hard, and the conversion of plant omega-3 fatty acids into docosahexaenoic acid is extremely slow.

"The conversion rate is almost less than 1 per cent."

Look for tuna canned in springwater or extra virgin olive oil. And try not to drain the oil out — it helps to retain omega-3.

Given the modest conversion rate, the Heart Foundation says it's important vegetarians and vegans still include marine-sourced omega-3 fats in their diet.

Little evidence for supplements

While some research shows fish oil supplements may help to reduce triglycerides in your blood, it's unclear whether they reduce your risk of cardiovascular disease.

Recent studies suggest the supplements may not be as helpful as previously thought in reducing the risk of heart attack or stroke.

Easy ways to eat healthy fats

Include 2–3 serves of fish a week (100–150g per serve).

Use nuts and seeds in your breakfast. Sprinkle ground linseed on cereal or try a handful of almonds sprinkled over yoghurt.

A handful of unsalted nuts make a healthy snack any time of the day.

Use oils and margarine spreads made from olive, sunflower, canola and safflower oils in cooking and on sandwiches and toast instead of butter.

Choose wholegrain bread with linseeds.