You probably already know too much fat is bad for you - but did you know too little of the good kind can leave you nutrient deficient, with high cholesterol and lacking in energy? Nutritionist Jo Lewin explains...
A certain amount of fat is required for health. It is needed to absorb certain fat soluble nutrients, manufacture cell walls and produce hormones. Fat is a valuable source of energy, and provides essential fatty acids that the body cannot make itself. However, not all fats are equal in terms of their effects on the body. Eating the right kinds of fat can help to protect you from heart and circulatory problems, but too much of other types can be detrimental to health. There are three main types of fat - saturated, monounsaturated and polyunsaturated - and they all have different roles in the body.
Saturated fat is frequently vilified as it has been associated with cardiovascular disease and high cholesterol. Red meat, butter, cheese, burgers and sausages, are high in saturated fat, as are ghee, coconut and palm oils. A diet high in saturated fat can increase blood fats including triglycerides as well as increase your risk of obesity, heart disease, type 2 diabetes and stroke. However, recent studies are now suggesting that dairy products such as cheese, do not appear to be as harmful as once thought. This may be because other nutrients in dairy, like calcium, may modify the effects on blood fats such as triglycerides.
Monosaturated fat found in olive, groundnut and rapeseed oils and nuts (almonds, cashews, hazelnuts, peanuts and pistachios), olives and avocados are particularly good for heart health. These fats can help lower the harmful LDL cholesterol.
Polyunsaturated fats are found in corn oil, sunflower oil, nuts and seeds (walnuts, pine nuts, sesame seeds and sunflower seeds). There are two main types of polyunsaturated fats: omega 3 and omega 6. These are termed essential fats as they cannot be made in the body and need to be obtained through the foods we eat. Polyunsaturated fats help to prevent your arteries becoming blocked and may lower blood pressure.
We obtain a high proportion of omega-6 fats in our western diet and low levels of omega-3. It is important that we eat adequate amounts of omega-3 - key foods are the oily variety of fish like salmon, herring and sardines as well as nuts like walnuts and seeds, such as chia and flaxseed. If the balance of these fats in the diet is in favour of the omega-6 fatty acids then it is likely to promote inflammatory conditions.
|Omega 3:||Omega 6:|
Salmon, mackerel, trout,
Corn, safflower, soya bean
1 portion of oily fish = approx 140g (cooked weight).
It is recommended that we eat two servings of fish per week, at least one of which should be the oily variety. If you don't like oily fish, you can get omega-3 fats from vegetable sources such as flaxseed, nuts and seeds, however it remains uncertain if the omega-3 in these foods brings the same heart healthy benefits as those in oily fish. If you are considering an omega-3 supplement, make sure you discuss with your doctor to ensure there are no contraindications with other drugs you might be taking.
A note on trans fat...
Trans fat is also known as hydrogenated fat. These are commonly used in manufactured food products such as shop-bought pies, pastries and cakes, favoured for their palatability and long shelf life. Trans fats are linked to high cholesterol levels and increased risk of heart disease and cancer. Read labels on any foods you haven't cooked fresh and try to avoid those containing hydrogenated oils. For more information on trans fats visit the NHS website.
Those who are trying to lose weight, lower cholesterol or have concerns about the amount of fat in their diets may want to reduce the total amount of fat they consume.
The recommended daily amount (RI) of total fat is 70g for men and women.
Within this amount, too many people eat too much saturated fat. Within the total amount of fat, the average we should eat is no more than 20g of saturated fat per day.
When shopping, compare nutrition labels so you can pick foods lower in fat. Use the per 100g column to compare.
Some packaging also uses the traffic light colour coding to reflect saturated fat levels. 'Red' reflects high saturated fat, 'green' indicates low saturated fat. Aim to eat red foods occasionally and green foods more frequently. Visit the NHS Choices pages for more information on food labelling.
So what counts as high fat and low fat?
- High: more than 17.5g of fat per 100g (packaging may be colour-coded red).
- Low: 3g of fat or less per 100g (packaging may be colour-coded green).
Look out for 'saturates' or 'sat fat' on the label: this tells you how much saturated fat is in the food.
High: more than 5g saturates per 100g (packaging may be colour-coded red).
Low: 1.5g saturates or less per 100g (packaging may be colour-coded green).
If the amount of fat or saturated far per 100g is inbetween these figures, that's a medium level, and packaging may be colour-coded amber.
- Where possible, choose the healthier mono and polyunsaturated fats instead of saturated fats to help protect your heart. Enjoy small amounts of butter and coconut oils while focusing on olive or rapeseed oils. Minimise your intake of lard, ghee and palm oils.
- Choose lean cuts of meat and make sure you trim any excess fat and remove the skin from chicken or turkey.
- Use a spray oil or measure out with a teaspoon instead of pouring oil straight from the bottle.
- Read food labels to help you make choices that are lower in total fat and saturated fat.
- Use alternative cooking methods such as baking, boiling, grilling, poaching, microwaving or steaming instead of frying or roasting so you do not need to add extra fat.
- Cut down on foods such as crisps, biscuits and avoid fried foods like samosas, bhajis, chips and doughnuts. Replace with healthier fruits and vegetables.
- Make your own salad dressings using ingredients such as balsamic vinegar, low fat yogurt, lemon juice and herbs.
- Choose lower fat dairy products such as semi-skimmed/skimmed milk, low-fat yogurt and crème fraiche.
- Try leaving out or using less butter and spreads on bread when making sandwiches - use nourishing foods like avocado, which is rich in monounsaturated fats.
- Cottage cheese, ricotta and light soft cheese are low-fat options. Keep your portions of cheese small or opt for less of the strong-flavoured varieties such as Parmesan - a little goes a long way.
*always check labels
Very low intakes of fat limit the amount of fat-soluble vitamins A, D, E and K and essential fats in our diet. This group of fat-soluble vitamins play essential roles in vision, skin, the immune system, hormone synthesis, bone health and the nervous and reproductive systems. A lack of fat in the diet will lead to reduced absorption of these essential vitamins.
However, all fats are high in calories, giving us nine calories for every gram eaten. So it is important for our weight and health not to eat too much. By reducing the unhealthy saturated and trans fats in our diet and replacing some of these fats with the healthier unsaturated fats we will be getting a better balance for our heart and overall health.
Just because a food packet contains the words 'low-fat' or 'reduced-fat', doesn't necessarily mean it's a healthy choice. The lower-fat claim simply means that the food is 30% lower in fat than the standard equivalent. So if the type of food in question is high in fat in the first place, the lower-fat version may also still be high in fat. For example, a lower-fat mayonnaise is 30% lower in fat than the standard version, but is still high in fat.
Also, foods that are marked 'low-fat' or 'reduced-fat' aren't necessarily low in calories. Often the fat is replaced with sugar, and the food may end up with the same, or an even higher, calorie content. To be sure of the fat content and the calorie content, remember to check the nutrition label on the packet.
Following restrictive, low-fat eating plans/diets may help you lose weight in the short term, but once you go back to old eating habits, your body will be more prone to storing fat and the weight will go straight back on again. If you want to lose weight, concentrate on eating a balanced diet, drinking sensibly and step up the amount of exercise you do. Be cautious of 'faddy' calorie counting and crash diets.
Most recipes can be made low-fat by replacing ingredients or reducing the quantity of fat used:
Tasty, healthy salads with low-fat dressings:
Chargrilled turkey with quinoa tabbouleh & tahini dressing
Barbecued fennel with black olive dressing
Winter slaw with warm celery seed dressing
Jo Lewin works as a Community Nutritionist and private consultant. She is a Registered Nutritionist (Public Health) registered with the UKVRN. Visit her website at www.nutrijo.co.uk or follow her on Twitter @nutri_jo.
This article was last reviewed on 11 May 2016 by nutritional therapist Kerry Torrens.
A registered Nutritional Therapist, Kerry Torrens is a contributing author to a number of nutritional and cookery publications including BBC Good Food magazine. Kerry is a member of the The Royal Society of Medicine, Complementary and Natural Healthcare Council (CNHC), British Association for Applied Nutrition and Nutritional Therapy (BANT).
All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.