Are dietary fats a dirty word?
What do you think of when you hear the word dietary fats? Most people think of obesity and heart disease but although fats do indeed contribute to the risk of heart disease, they certainly are not the only culprit as far as obesity is concerned. Not all fats are bad.
https://my.clevelandclinic.org/health/articles/11208-fat-what-you-need-to-know
Do we need dietary fats?
Yes! Indeed your body needs fatty acids to survive, and cannot produce them from other foods. Fat are necessary for:
- Regulating hormone production.
- Keeping your skin and hair healthy.
- Absorbing vitamins A, D, E and K (fat-soluble vitamins).
- Insulating your body and keeping it warm.
How did fats get such a bad name?
In 1957 the American Heart Association mounted a campaign at reducing fat consumption as they believed that saturated fat caused heart disease. Over the next few decades Americans cut their consumption of fats by 20%.
However, instead of eating healthy fruit and vegetables they ate more processed foods promoted by the food industry as ‘low fat’ or ‘fat free.’ Manufacturers stuffed their products with processed vegetable oils such as margarine. Dairy fat consumption went down; sugary carbs went up and the obese population increased along with diabetes type 2!
Additionally, compared to 30 years ago we eat around 180 calories a day more in snacks. Junk food is packed with sugar and salt.
Question: “what unhealthy snacks could you get rid of and replace?”
How much fat should we eat a day?
The dietary reference intake (DRI) for fat in adults is 20% to 35% of total calories. That is about 44 grams to 77 grams of fat per day if you are eating around 2,000 .
Fats are calorie dense: 9 calories per gram.
A tablespoon of olive oil has more calories than a banana!
The bad dietary fats – Saturated Fats
Saturated fats are generally animal products such as cheese, butter, whole milk, ice cream, fatty meats and are solid at room temperature. Coconut and palm oils are also saturated fats. They they raise your’e LDL cholesterol levels and are the number 1 contributor to heart disease and high blood pressure.
Saturated fats therefore should comprise less than 10% of your diet.
Tips:
- Choose lean protein
- Choose low fat dairy products
- Cut back on butter and fried foods
The Good dietary fats – Unsaturated Fats
Unsaturated fats come in two forms: mono and poly. Monounsaturated fats : olive and canola oil.
Polyunsaturated fats: sunflower, rapeseed oil.
Advice: rather than saturated fat, eat more unsaturated fat.
The Ugly Fats – Why are Trans-fats bad?
Trans-fats are artificial fats made by infusing vegetable oil with hydrogen – a process called hydrogenation. They are cheap and are used to keep foods fresh and can also be used for frying repeatedly. They are often found in fast food, cakes and biscuits.
There are no health benefits or safe levels of consumption levels – so, avoid these!
Basically, anything that has a long shelf life possibly contains partially hydrogenated oil or trans-fats.
https://www.healthline.com/nutrition/why-trans-fats-are-bad
https://www.diabetes.co.uk/food/trans-fats.html
Where have they been banned?
As an indicator of their deleterious qualities: they have been banned in Denmark and all New York restaurants. The governor of California Arnold Schwarzenegger recently passed legislation banning all trans-fats.
What are the risks of trans-fats?
So what are the risks? They increase the risk of prostrate tumours by 100% and breast cancer by 75%. When consumed early on in life they increase the risk of Type 2 Diabetes.
They increase bad LDL cholesterol and decrease healthy HDL cholesterol. In addition, if that’s not bad enough, they help to cause depression, heart disease, Alzheimer’s and many more harmful diseases!
Advice: avoid margarine and frying fats. It’s much better to fry in olive oil.
Fats – Omega 3 and 6
Omega 3 and 6 are essential polyunsaturated fats and are good for the heart and body and are used for energy. A Mediterranean diet is full of these as it has lots of fruits vegetables, olive oil, nuts and fish.
Omega 3 fats
They are found in oily fish such as salmon, herring, mackerel and sardines. Vegetable sources such as flaxseeds and walnuts. They help protect the rhythm of the heart, ease inflammation and inhibit the formation of clots in the blood stream. In addition they lower the level of of triglycerides which carry fat around the blood stream.
The fish source is better than the vegetable source as plant forms poorly convert to EPA and DHA which is more beneficial.
Eicosapentaenoic acid (EPA): This 20-carbon fatty acid’s main function is to produce chemicals called eicosanoids, which help reduce inflammation. EPA also helps reduce symptoms of depression
Docosahexaenoic acid (DHA): A 22-carbon fatty acid, DHA makes up about 8% of brain weight and is extremely important for normal brain development and function
- Salmon: 4.0 grams EPA and DHA
- Mackerel: 3.0 grams EPA and DHA
- Sardines: 2.2 grams EPA and DHA
- Anchovies: 1.0 grams EPA and DHA
- Chia seeds: 4.9 grams ALA
- Walnuts: 2.5 grams ALA
- Flaxseeds: 2.3 grams ALA
Omega 6 fats
They are mainly obtained from vegetable oils and are also beneficial: they lower LDL and boost HDL and help improve the body’s sensitivity to insulin. The most common omega-6 fat is linoleic acid, which can be converted into longer omega-6 fats such as arachidonic acid (ARA).
https://www.health.harvard.edu/newsletter_article/no-need-to-avoid-healthy-omega-6-fats
Alpha-linolenic acid (ALA): This 18-carbon fatty acid can be converted into EPA and DHA, although the process is not very efficient. ALA is mainly used by the body for energy
Omega 6 fats are found in sunflower oil, walnuts, sunflower seeds.
Here are the amounts of omega-6s in 100 grams (3.5 oz) of the following foods:
- Soybean oil: 50 grams
- Corn oil: 49 grams
- Mayonnaise: 39 grams
- Walnuts: 37 grams
- Sunflower seeds: 34 grams
- Almonds: 12 grams
- Cashew nuts: 8 grams
The Institute of Medicine recommends getting 5 – 10% of daily calories from Omega 6 fats. That’s 11-22 grams for someone on a normal 2000 calorie diet. In practical terms, an ounce of walnuts weighs 11 grams!
However, in the typical Western diet we are eating far to much Omega 6 compared to Omega 3 by about 15-1. An excess of Omega 6 can lead to inflammation. The advice is of an ideal balance of 4-1 by most experts.
Summary
Your diet should contain 20-35% fats.
Fats contain 9 calories per gram.
Choose unsaturated fats rather than saturated.
Saturated fats should make up no more than 10% of your diet.
Cut out trans-fats completely.
Consume omega 3 and 6 fats but give priority to omega 3
https://www.healthline.com/nutrition/omega-3-6-9-overview
