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Protein is essential for growth. We use it to build, maintain and repair muscle tissue; to produce hormones, enzymes, and antibodies, to transport nutrients and oxygen throughout the body, and to regulate the balance of body fluids. If insufficient carbohydrate is available, protein can also be used for energy. However, carbohydrates cannot perform some of the functions that protein does. Unlike carbohydrate and fat, the body cannot store protein, therefore we need to regularly eat small amounts of protein rich foods.
Protein in the dietProtein includes fish / meat / legumes / dairy and soy products / eggs
Foods come with more than one key nutrient (for example protein), but will have additional components (for example carbohydrate and fats). Protein quality refers to the amount of protein plus the other nutrients, for example –
- A steak with fat has protein plus saturated fat – 40 grams of steak (about the size of the palm of your hand) has approximately 12 grams of saturated fat
- 250 grams of cooked dry beans, for example a half a cup of kidney beans to make a Mexican style taco, includes 0 fats and 758 milligrams of sodium.
Protein food choices - variety is key
- Eat a variety of foods from the Protein Foods Group each week.
- Choose fish twice a week instead of meat or poultry. Include fish such as sardines, salmon, tuna and herring.
- Eat plant protein foods often. Try beans and peas (kidney beans, black beans, white beans, split peas, chickpeas/garbanzo beans e.g. in hummus), soy products (tofu, tempeh, veggie burgers), nuts and seeds. Choose unsalted nuts or seeds.
- Make meat and poultry lean or low fat. Choose lean or low-fat cuts of meat.
- Trim or drain fat from meat and remove poultry skin.
- For lunch make that sandwich with roast beef, chicken or tuna instead of salami or luncheon sausage, which are high in fat and sodium.
- One egg a day, on average, does not increase the risk for heart disease.
Foods that provide protein are divided into two groups; complete and incomplete proteins.
Complete and incomplete proteins
Complete proteins are those foods that provide all of the essential amino acids our body needs in sufficient quantity to support growth and maintenance of body tissues. Since essential amino acids cannot be made by the body, they must be acquired by food. Foods that contain complete proteins are said to provide ‘higher quality’ of protein.
Incomplete proteins lack one or more of the essential amino acids in sufficient quantity to support growth and maintenance of body tissues. Foods that contain incomplete amino acids are said to provide ‘lower quality’ of protein.
|COMPLETE PROTEINS||INCOMPLETE PROTEINS|
Making complete proteinsWhile most people choose to include some animal products in their diets, it is possible to get enough nutrients by eating a variety of plant foods each day. Making incomplete proteins complete is as simple as ‘baked beans on toast’ - combining baked beans and whole grain bread.
Incomplete proteins don’t have to be combined at the same meal to get the benefits, they just need to be consumed throughout the course of a day.Cultures throughout the world combine foods to make complete proteins.
Some examples –
- Rice and beans: Mexico
- Tofu and rice: Asia
- Pasta and beans: Italy
- Hummus and pita bread: Middle East
|Tofu (soy bean)||Rice||Tofu with rice|
|Peanuts||Whole wheat||Peanut butter on wholegrain bread sandwich|
|Chilli beans||Cornmeal||Bean taco|
How much protein do we need?About 46 grams for most women and 56 grams for most men.
The amount of food from the Protein Foods Group you need to eat depends on age, sex and level of physical activity. Most people eat enough food from this group, but need to make leaner and more varied selections of these foods.
There are some important exceptions.
Recent research suggests that older adults need to consume more protein in order to maintain and build muscle mass and compensate for a decreased ability to absorb protein: approximately 1 to 1.2 grams for people over 60 per kilogram of body weight per day — and spread throughout the day, rather than predominantly at dinner. Very active people and athletes in training, especially if engaged in strength training, probably need more protein than general recommendations.
Have plenty of variety and types including fish, meat and legumes.
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The amount of meat consumed in different countries varies enormously affected by availability and cultural differences. Meat is held in high esteem in most communities and is often regarded as the central food round which meals are planned. Various types of meat are sometimes made the basis of festive and celebratory occasions, and from the popular as well as the scientific point of view, it is regarded as a food of high nutritive value.
Where a typical diet is heavily dependent on one type of cereal or root crop, meat, even in small amounts, complements the staple food. It provides a relatively rich source of well absorbed iron and also improves the absorption of iron from other foods, its amino acid composition complements that of many plant foods, and it is a concentrated source of B vitamins, including vitamin B12 which is absent from plant foods. United Nations / Food & Agricultural Organisation FAO
Red meat in the dietThere is a lot of seemingly conflicting research about eating meat, just about everyone advises to do it sparingly.
Choose lean cuts of red meat and cut off any visible fat before eating. Avoid heavily marbled meats (streaks of fat through the meat). Purchase premium mince with less fat if you can, and with all mince, drain off the fat after cooking and before eating. Remove the skin from chicken before eating. Allow casseroles, stews and curries to cool and skim the fat that settles on top.
Plant based substitutes are recommend at least 3 times a week. Just remember, if you are substituting meat with plant-based protein, these will contain carbohydrates. As a protein, meat has less effect on blood glucose.
Steam, bake, broil or grill for healthy cooking and try to reduce fried foods.
Heart and Cancer researchResearch conducted at Harvard School of Public Health has found that eating even small amounts of red meat, especially processed red meat, on a regular basis is linked to an increased risk of heart disease and stroke, and the risk of dying from cardiovascular disease or any other cause. Conversely, replacing red and processed red meat with healthy protein sources such as poultry, fish or beans seems to reduce these risks. Harvard TH Chan School of Public Health
People with less healthy diets are more likely to develop cancer. Many studies have been conducted looking at the association between diet and cancer, and experts agree the food we eat can affect our risk of cancer. A recent study suggested around one in 20 cancers in the UK may be linked to people eating fewer than five portions a day of fruit and vegetables.
Eating lots of red or processed meat increases the risk of bowel cancer. Red meat includes all fresh, minced and frozen beef, pork and lamb. Processed meat includes ham, bacon, salami and sausages.
Around a quarter of bowel cancer cases in men, and around a sixth in women, are linked to eating red or processed meat. Bowel cancer risk increases by more than a quarter (28%) for every 120g of red meat eaten per day, and by almost a tenth (9%) for every 30g of processed meat eaten per day. Processed meat is more strongly linked to cancer risk than red meat. World Cancer Research Fund / American Institute for Cancer Research
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Image credit Ramon Freasquez
Fish is a food of excellent nutritional value, providing high quality protein and a wide variety of vitamins and minerals, including vitamins A and D, phosphorus, magnesium, selenium and iodine in marine fish.
Experts agree that, even in small quantities, fish can have a significant positive impact in improving the quality of dietary protein by complementing the essential amino acids that are often present in low quantities in vegetable-based diets.
But recent research shows that fish is much more than just an alternative source of animal protein. Fish oils in fatty fish are the richest source of a type of fat that is vital to normal brain development in unborn babies and infants. Without adequate amounts of these fatty acids, normal brain development does not take place.
The main constituent of fish flesh is water, which usually accounts for about 80 per cent of the weight of a fresh white fish fillet but can vary from 30 to 90%.
The amount of protein in fish filet is usually somewhere between 15 and 20 per cent, but values lower than 15 per cent or as high as 28 per cent are occasionally met with in some species.
All proteins, including those from fish, are chains of chemical units linked together to make one long molecule. These units, of which there are about twenty types, are called amino acids, and a certain number of them are essential in the human diet for the maintenance of good health.
The fat content of fish can vary very much more widely than the water, protein or mineral content and can vary according to the seasons and availability of food for the fish. The term fat is used for simplicity, although the less familiar term lipid is more correct, since it includes fats, oils and waxes as well as more complex, naturally-occurring compounds of fatty acids.
The amount of carbohydrate in white fish muscle is generally too small to be of any significance in the diet; hence no values are given in the tables. In white fish the amount is usually less than 1 per cent, but in the dark muscle of some fatty species it may occasionally be up to 2 per cent. Some molluscs, however, contain up to 5 per cent of the carbohydrate glycogen. UN Food and Agricultural Organisation FAO
Mercury and fishMercury occurs naturally in the environment and accumulates in fish in the form of methyl-mercury. Our most common exposure to mercury is through fish and other seafood. Most people are not exposed to levels high enough to harm the nervous system as the body excretes it over time so accumulation is usually not a problem. However, unborn babies are potentially more sensitive to the harmful effects and their exposure to mercury should be limited. It is also recommended that if you eat a lot of fish, you restrict consumption of certain species high in mercury.
Caution: It is particularly important that women who are pregnant, or planning to be, monitor their fish intake as there are unresolved issues around levels of mercury in some fish and its potential impact on the growing foetus. Please consult your healthcare professional / dietitian. Ministry of Primary Industry: Food Smart
Fish in healthy eating patternsChoose un-battered fillets of fish, either fresh or frozen. Choose some ‘oily’ fish species such as tuna, salmon, kingfish, snapper, trout, herring, eel or seafood such as mussels. An inexpensive way to include fish, such as sardines, is canned in spring water, not brine or oil. Eating one to two servings of oily fish a week can benefit heart health.
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PROTEIN: LEGUMES / PULSES
Legumes include all types of beans and lentils.
The term "legume" refers to the plants whose fruit is enclosed in a pod. Legumes represent a vast family of plants including more than 600 genera and more than 13,000 species.
Legumes are nutrient rich, containing dietary fibre, protein, carbohydrates as well as phytonutrients and vitamins and minerals.
Legumes come in a variety of shapes, sizes and colours and can be consumed in many forms including split, ground into flours or dried, canned, cooked or frozen whole legumes.
Dried peas, edible beans, lentils and chickpeas are the most common varieties of pulses.
Soybeans and peanuts differ because they have a much higher fat content, whereas pulses contain virtually no fat.
Green beans, peas, snow peas, runner beans, snap peas
Pulses do not include fresh beans or fresh peas, although they are related to pulses because they are also edible seeds of podded plants. While rich in vitamins, minerals and fibre, vegetable beans are not a rich source of protein compared to their dried counterparts.
A big advantage that pulses (beans) have over meat in terms of protein is their fat content – there is very little fat in most beans compared to meat, which is one of the biggest contributors to our saturated fat intake.
Beans boast a low glycaemic index and contain complex carbohydrates, which are digested slowly. These facts make beans a good choice for people needing to keep their blood glucose in the normal range.
Well known dried legumes include chickpeas, butter beans, haricot (navy) beans, cannellini beans, red kidney beans, adzuki beans, black-eyed beans and soybeans, dried yellow and green peas, lentils.
|Adzuki beans||Adzuki beans are small, red beans that are grown throughout East Asia. These legumes are also called aduki or azuki beans. The nutty flavour of adzukis is found in savoury dishes and a sweet adzuki bean paste that is used as a filling in many popular Asian desserts, including ice cream.|
|Haricot / Navy beans
|Navy beans are the beans we find in a can of Baked Beans.
Baked Beans can be high in salt – light versions can have a third less salt than standard versions.
Sugar is also added to baked beans – standard versions can contain between 4% and 8% while light versions are about 5% sugar.
Check the labels when comparing products.
|Kidney beans||Kidney beans are a good source of cholesterol-lowering fibre, as are most other beans. In addition to lowering cholesterol, kidney beans' high fibre content prevents blood glucose levels from rising too rapidly after a meal.|
|Chickpeas (garbanzos)||Garbanzo beans, commonly known as chickpeas, are among the most widely used legumes. Chickpeas are a vegetable that have been cultivated throughout the Middle East and India for thousands of years. They are a Middle Eastern favourite and the foundation of hummus, a popular dip made by puréeing garbanzos with olive oil, tahini (sesame seed butter), lemon juice and garlic. When hummus is eaten with bread it serves as a complete protein, similar to other combinations of grains and legumes.|
|Lentils (dal)||Lentils (dal) are low in fat and high in protein and fibre, and they have the added advantage of cooking quickly. They come in a variety of colours and feature in many types of cooking.|
|Soy beans||Soy milk, tofu, tempeh or green soybeans (edamame) or roasted soy nuts.|
To reduce the salt content in canned beans, thoroughly rinse the beans in cold water before cooking
Using the Healthy Eating Plate as a guide at dinner or lunch
¼ plate baked beans, ¼ plate slice of whole grain bread, ½ leafy green salad
¼ plate kidney beans, ¼ plate rice (preferably brown), ½ broccoli and cauliflower or carrots
¼ plate (several chunks) tofu, ¼ plate rice, ½ plate stir fried mixed vegetables
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Image credit Archenzo Varesse
Milk, yoghurt and cheese are sources of high-quality proteins. Individual milk proteins have a wide range of potential health benefits and functional properties. In milk approximately 80% of the protein is casein and 20% is whey and contains all of the essential amino acids for a healthy body along with calcium and vitamins.
Milk and yoghurt contain carbohydrates as a sugar called lactose and should be considered within a daily carbohydrate intake. Milk is approximately 4.9% carbohydrate in the form of lactose. Before the body can use it, the bond must be broken by the enzyme lactase in the small intestine. People that have decreased activity of lactase in the small intestine may have problems digesting lactose and this is referred to as lactose intolerance.
Milk is approximately 87% water. Water does not provide a nutritional benefit in the same manner as proteins or vitamins, for example. However, water is extremely important in human metabolism.
Milk is approximately 3.4% fat, depending on the source and type of milk – low fat etc. The fatty acids in milk fat in regular milk are approximately 65% saturated, 29% monounsaturated, and 6% polyunsaturated.
Cheese can form part of a healthy diet, but it’s a good idea to keep track of how much you eat and how often. Most cheeses – including brie, stilton, cheddar – contain between 20g and 40g of fat per 100g. Foods that contain more than 17.5g of fat per 100g are considered high in fat. Some cheeses can also be high in salt. An option is to choose reduced-fat hard cheeses, which usually contain between 10g and 16g of fat per 100g. A few cheeses are even lower in fat (3g of fat per 100g or less), including reduced-fat cottage cheese and quark.
As a liquid extract of soybeans, it does not contain any lactose, soymilk is often used as a substitute for people with lactose intolerance and because it’s derived from a plant source, it’s also a popular cow’s milk substitute. Soymilk contains the most protein of all the non-dairy alternatives. Foods from soy are the only plant-based complete protein source.
Rice milk, made from boiled rice, brown rice syrup, and brown rice starch. Compared with dairy milk, the rice variety has considerably less protein and, unless added during processing, a very small amount of calcium. It can also be high in sodium and carbohydrates.
Almond milk is made from ground almonds, water and usually a sweetener. It contains very little protein, and is devoid of most B vitamins, lacks many essential trace elements, including zinc and copper, and contains little, if any, of the essential fatty acids.
It’s a good source of calcium and protein.
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