Nutrition
Fats
Did you know?
Nearly one quarter of Kiwis have total cholesterol levels higher than 6.5mmol/L (doctors say below 5 is best).
News in a hurry
The bottom line is, we eat too much fat, especially the harmful fats.
- Too much fat can make us fat, especially if combined with a low level of physical activity.
- Eating too much of certain types of fat, especially saturated fat and trans fats, can also increase our risk of heart disease and a number of other diseases.
- Remember, we all need some fat in our diets – so it’s best to choose the healthy ones!
- A typical New Zealander’s diet contains around 35% of total energy as fat, whereas the 2005 goal was 30-33%, and more recently that’s been adjusted to 20-25%. Our saturated (bad) fat intake is 15% of total energy, instead of 12%.
Tips to reduce your fat intake
- Replace the ‘need’ for fatty foods by eating more: breads and cereals, vegetables and fruits, low-fat dairy products, lean meat, seafood, chicken, eggs and legumes (peas, beans, lentils).
- Make vegetables the major part of your evening meal.
- Pick unsaturated fat over saturated or trans fat, ie, fish over beef, olive oil over butter, nuts over chips etc.
- Choose lean meats and replace with fish when you can. The National Heart Foundation recommends we eat fish (not fried) twice a week.
- Buy chicken with skin on (it’s cheaper that way) then remove it prior to, or after cooking, and give it to the cat – she’ll be your mate for life!
- Grill, boil, steam or microwave food.
- Use less spread on breads and muffins. Try sandwiches with just filling and no spread at all.
- Use fewer sauces and dressings,or use low fat options.
- Make the switch to low fat milk, cheese, yoghurt and ice-cream - find low fat versions you love.
- Make takeaways an occasional treat. If you really love deep fried foods, make them a rare treat.
What are fats and why are they important?
Fats are a group of compounds that make an important contribution to nutrition, despite their bad press. Fats are major sources of energy, and the only form in which the body can store energy for a long period of time. Fats also:
- help control body temperature
- give some protection to internal organs
- supply essential fatty acids (those that can’t be made by the body)
- make up the structure and function of cell membranes
- ensure absorption of the fat-soluble vitamins
- fill us up
- make some foods taste better.
However, eating too much fat, particularly saturated fat, contributes to the development of serious diseases such as obesity, type 2 diabetes, coronary artery disease and certain cancers, eg, colorectal cancer.
Getting the right balance of how much and what type of fat to eat is important. Evidence suggests a minimum requirement is low; in fact there is no minimum fat requirement set for adults. Nutritionists say we need only small amounts of fat, which is easily achieved by following the New Zealand eating guidelines.
Harmful fats
Saturated fat
Considered the bad fats because of their link to heart disease, saturated fats should be eaten in small amounts. They come predominantly from animal products, especially fatty meats, and dairy products, like butter, full-fat milk and cheese, but also from coconut and palm oil.
Fast foods are also major contributors. Eating saturated fat increases both good (HDL) and bad (LDL) cholesterol levels. Controlling your LDL cholesterol level is the best known way of lessening your risk of coronary heart disease, so eating fewer of the foods that contain large amounts of saturated fat is an important way to do this.
Trans fat
We don’t need these fats in our diet at all. Although they are unsaturated, when food manufacturers 'hygrogenate' them to make them firm, they become more like saturated fats in their effects on blood cholesterol; not only do they increase our levels of bad (LDL) cholesterol, but they also decrease our levels of good (HDL) cholesterol.
Trans fats do not occur naturally – except in small amounts from cows and sheep. Mostly they come from manufactured foods, like some margarines and peanut butters, biscuits, crackers, cakes and potato chips. However, most spreads now available in New Zealand and Australia only contain a small proportion of trans fats.
Check food labels to see if what you are buying contains trans fats.
Dietary cholesterol
Cholesterol is the fatty substance made by the liver from the fats you eat. It is used for building cell membranes, hormones and bile salts. We also get cholesterol directly from our diet from: meat, poultry, seafood, eggs, dairy products, lard and butter.
Too much cholesterol circulating in our blood, gets stuck in blood vessel walls, making them narrow and harder. This increases the risk of heart disease. A high blood cholesterol level is usually due to a diet too high in saturated fat, but in some people it’s because they have a genetic (inherited) susceptibility to high blood cholesterol.
What are lipids or lipoproteins?
Cholesterol is carried around the body on different types of lipids or lipoproteins: very low-density lipoproteins (VLDL); low-density lipoproteins (LDL) high-density lipoproteins (HDL) and triglycerides.
VLDLs are made in the liver and they carry fats to different parts of the body. Once they drop off some of their fat load, they become LDLs, which carry the remaining cholesterol around the body.
LDL has been dubbed the ‘bad’ cholesterol, and it's important to have low levels of this.
HDL is termed the ‘good’ cholesterol, as it carries bad cholesterol back to the liver for processing.
Tip: to remember which is good and which is bad think: L for lethal, H for healthy!
Triglycerides are the body's storage form for fat, and high levels are associated with heart disease.
The National Heart Foundation maintains if you have high levels of both triglycerides and blood cholesterol, you run a greater risk of cardiovascular disease. This is particularly high if you also have a high level of LDL cholesterol and a low level of HDL cholesterol.
Blood lipid levels to aim for through diet and exercise, or from medication if indicated by your doctor:
Total cholesterol LESS THAN 4 mmol/L
LDL cholesterol LESS THAN 2 mmol/L
HDL cholesterol EQUAL TO/GREATER THAN 1 mmol/L
Total cholesterol/HDL ratio LESS THAN 4 mmol/L
Triglycerides LESS THAN 1.7 mmol/L
New Zealand guidelines states that a reduction of 1mmol/l in LDL-cholesterol reduces your risk of coronary heart disease and stroke by a third.
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Healthy fats
When choosing what fat to eat, the best way to go is to replace saturated fats with unsaturated fats - monounsaturated and polyunsaturated - as they can lower your risk of heart disease by reducing cholesterol levels in your blood.
Monounsaturated fatty acids
These fats come from fish and animals, and many plants: rapeseed, peanuts, macadamia nuts, pistachios, hazelnuts, almonds and oils from avocado, olive and canola. Mono-unsaturated fats decrease total and LDL cholesterol, with little effect on HDL cholesterol, thought to protect against coronary heart disease. In other words, they either lower blood cholesterol or have little effect on it.
Polyunsaturated fatty acids
The so-called good fats, polyunsaturated fatty acids (PUFAs) are mainly obtained from eating fish and plant oils (safflower, sunflower) and some animal tissues. This group of fats is often referred to as omega-3 and omega-6 fatty acids – the heart-friendly fats.
Omega-6 fats are found in sunflower seeds, soy bean and corn oils. They can lower total and LDL cholesterol.
Omega-3 fats are obtained from oily fish and plants such as soy bean, mustard, walnut, canola and linseed (flax) oils. They are thought to: reduce blood pressure, reduce the incidence of blood clots, a cause of strokes and heart attacks; reduce the chance of developing ulcerative colitis (inflammation of the colon) and Crohn’s disease (inflammation in the small intestine); be protective against childhood asthma; and help with mood swings in people who experience bipolar disorder and depression.
While omega 3 is abundant in salmon, sardines, mackerel, herrings, kahawai and trevally, it’s important to remember fish battered and deep fried is not a good choice due to its extremely high fat content.
And remember, excess intake of fat of any kind contributes to increased body weight, so watching your intake is important - even of the good stuff.
How much fat do Kiwis eat?
New Zealand’s National Nutritional Survey 1997 showed the fat intakes of New Zealand adults are above the upper limit of recommended levels. We eat too much saturated fat and not enough mono- or polyunsaturated fats. The typical New Zealand diet contains around 35% of total energy as lipid (15% saturated fat, 12% monounsaturated fat and 5% as polyunsaturated fat). This is compared with some African and Asian countries where total dietary fat can provide as little at 10% total energy!
How much should we eat?
The National Plan of Action for Nutrition proposed a decrease in the intake of total fat by 20%, from 37-38% to 30-33% by the year 2005, and to decrease the intake of saturated and trans fatty acids to provide no more than 12% of total energy, by the year 2005. We wont know the outcome until the results of the next national nutirtional survey are released.
Reduce your fat intake
Sometimes it’s hard to eat less fat – reasons may be fatty food tastes better, it’s easier to eat takeaways, or I just ‘cant’ do it!
Tips to make eating less fat easier
- Every day eat at least 6 servings of breads and cereals, at least 5 of vegetables and fruits, at least 2 of low-fat milk, yoghurt, ice cream or cheese, and at least 1 of lean meat, seafood, chicken, eggs or legumes (peas, beans, lentils).
- Choose healthier snacks, like fruit, low fat crackers and vegetables, and avoid potato crisps, biscuits and pastries.
- Trim fat from meat and remove chicken skin.
- Grill, boil, steam or microwave instead of frying and roasting.
- Don't cook food in animal fat, instead choose a vegetable oil or mono-unsaturated oil (olive, canola or avocado), or a poly-unsaturated or mono-unsaturated margarine, instead of butter.
- Use less spread on breads and muffins.
- Choose low-fat milks, yoghurts and cheeses, eg, cottage cheese, edam and mozzarella.
- Use fewer sauces and dressings, but when you do use them choose low-fat varieties.
- Limit your intake of high fat and processed meats, like sausages and luncheon meat.
- Make takeaways, like deep fried fish, or chicken, and chips, an occasional treat.
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