Lesson 9: Fats

Role of dietary fat

Fat is the third macronutrient that your body needs in large quantities. It is responsible for the transport of nutrients to maintain the health of your cells, hormones, and nervous system.

The fat in your diet has several major functions:

• Helps production and balance of hormones (particularly testosterone and estrogen)

• Forms cell membranes

• The human brain is 60% fat

• Helps transport important vitamins around the body

• Provides your body with Omega 3 and 6 (which it can’t make on it’s own)

• Provides your body with energy. At 9 Kcal per gram, it is the most energy dense macronutrient (more than double of protein or carbohydrate)

Note: Even though it is so dense with energy, it is a complicated and lengthy process to use as fuel for your body (your body prefers carbohydrates as its main source of energy). 

Energy surplus and deficit

If you are in an energy surplus from your food intake, any additional dietary fat will be converted and stored as body fat. You need some of this to protect your organs and to keep you warm, but body fat in excess is known to contribute to lower health and quality of life.

If you are in an energy deficit, your body will use your glycogen (stored glucose). Once this depletes, your body will turn to fat for fuel. This process takes a lot of oxygen which your body needs for exercise.

Types of dietary fat

Fats are molecules that are made up of carbon and hydrogen. The different types of fats are characterised by this ratio:

• Saturated fats have more hydrogen in them which ‘saturate’ the carbon.

• Unsaturated fats have less hydrogen in them than saturated fats.

• Trans fats have hydrogen added to them, usually through a manufacturing process called ‘hydrogenation’

Both saturated and unsaturated have a role to play in maintaining health, whereas trans fats do not and can be found in heavily processed foods. This places most commercially produced items like cookies and pastries in the ‘eat (far) less’ zone of the food continuum.

Saturated fats

These types of fats are usually solid or semi-solid at room temperature and can be found in foods that include:

• Butter

• Coconut oil or coconut milk/cream

• Cream

• Fatty areas of meat

• Palm oil

• Whole fat milk, cheese, and yoghurt

Unsaturated fats

There are two types of unsaturated fats; monounsaturated fats and polyunsaturated fats. Both of these types of fats tend to be liquid at room temperature.

Foods high in monounsaturated fat include:

• Canola oil

• Sunflower oil

• Egg yolk

• Olives

• Peanuts

• Almonds

• Avocados

• Chicken fat

Foods high in polyunsaturated fats include:

• Sesame seeds (and oil)

• Mayonnaise

• Chia seeds

• Flaxseeds 

• Fish

• Pine nuts 

• Walnuts 

Unsaturated fats are where your body gets omega-3 and omega-6 from (both of which are polyunsaturated). Your body cannot make this on it’s own so it is important to get it from your food sources. These are responsible for keeping the brain cell membranes healthy.

Having a healthy cell membrane will mean that neurotransmitters like serotonin can be received in the brain more easily. It also helps with brain development and to slow degenerative brain disease.

Trans fats

Trans fats don’t occur naturally most of the time. These are fats that are created through industrial processing. This happens by binding hydrogen to an unsaturated fat to make it saturated, usually to turn a liquid fat into a solid fat. Trans fats are commonly used for commercially baked products like cookies, pies, donuts, etc.

This artificial process isn’t received well by your body. Unlike normally occurring saturated fats, trans fats don’t get recycled in the body. They create a build up of LDL (low density lipoproteins, often called the ‘bad’ cholesterol) in your arteries. Over time, this build up is known to increase your risk of heart disease.

In 2015 the FDA announced that they are not recognised as safe and will need to be phased out of production.

Trans fats are commonly found in heavily processed foods.

How much fat should you have?

In a balanced diet, you should aim to have 3 servings of fat per day across 3 meals in general. As with the other macronutrients (carbohydrate and protein), having variety of whole foods in your diet is important in order to get a good balance of unsaturated and saturated fats.

A single serving of fat is equal to the size your thumb.

Tips:

• Choose whole food options.

• Read labels carefully (although not all processed foods name trans fats on the label or ingredients list, so minimising processed foods is a good general guide).

• Substitute snack options for nuts, seeds, or a little bit of dark chocolate.

• Nuts and seeds in salads will add variety in nutrients, but also provide added taste and texture to your meal.

• Use a variety of cooking oils: extra virgin olive oil, coconut oil, avocado oil are great options that add flavour to your dishes.

Task: Healthy Fats

You will find the task for this lesson attached in the same email that you received this one.