Your body’s primary source of energy for aerobic activities is fat. Although fat is slow to burn, it provides more energy with every gram burned, than the quick release limited glycogen stores that your body will predominantly use for higher intensity activities. For endurance athletes, or those wishing to lose weight through training, extended (1-2 hour) aerobic zone workouts are recommended to best utilise this endurance fuel source.
Fat is often misunderstood by people. When you eat fat, this doesn't mean your body will store that food as fat. If you've been mislead by this notion - get over it right now! The human body can manufacture most of the fats its needs, including cholesterol and some fatty acids but there are two essential fats (or fatty acids) which cannot be manufactured in the body and which must be obtained from food. They are linoleic acid and
alpha-linolenic and you might know of them as the Omega-3 and Omega-6 fatty acids.
Most of us know that fats come in two types - saturated and un-saturated.
Good Fats - Unsaturated
The good fats are the un-saturated type. These un-saturated fats are predominantly found in plant foods. There are two categories of un-saturated fats; mono-unsaturated and poly-unsaturated.
Monounsaturated Fats
Some examples of foods with monounsaturated fat content are: olive oil, avocado, hazelnuts, cashews and almonds, and some seeds. These should remain in your diet. One important reason for this is that unsaturated fats tend to lower blood cholesterol when they replace saturated fats in the diet.
Polyunsaturated Fats
Some examples of foods with polyunsaturated fats are fish (tuna, mackerel, hearing, trout, salmon), soyabean, most vegetable oils and margarine, and some nuts (walnuts, brazil nuts) and sunflower seeds.
Polyunsaturated fats are also grouped as either Omega-3 fats or Omega-6 fats. Omega-3 fats are found in both plant and marine foods. Omega-3 deficiences have been identified as a common link with people suffering depression, decreased memory and a long list of undesirable, but common symptoms. The primary source of omega-6 fatty acid in the diet is linoleic acid from the oils of seeds and grains. However, it is the ratio of Omega-3 to Omega-6 that has been reported to be the main cause of
breakdown of human health resulting from our modern diet.
In today's western diet, it is estimated that the ratio of Omega-6 to Omega-3 is approximately 7:1, however the diet of our ancestors (hunters & gatherers) would have consisted of approximately equal parts Omega-3 to Omega-6. The increase of Omega-6 in our diets (through high intakes of margarine, safflower & sunflower oils) at the expense of Omega-3 has occurred since the beginning of agriculture and has accelerated with cattle & sheep being fed increasingly on grains rather than grass. The research clearly shows that it is this imbalance between the ratio of Omega-3 to Omega-6 fatty acids that has contributed to diabetes, cancer, heart disease, and allergies.
Bad Fats - Saturated
The bad fats are saturated fats and are found mostly in many takeaway "fast" foods, and commercial products such as biscuits, cakes and pastries (also contain trans-fats). Whilst naturally occuring trans fats are found in small amounts in milk, cheese, beef and lamb, it is the synthetic version of trans fats resulting from hydrogenation that should be avoided. All saturated fats increase blood cholesterol levels which contributes to the risk of heart disease, hence whilst meat remains a recommended food for a healthy diet, you'll note you'll always be advised to eat only "lean" cuts of meat to minimise your uptake of saturated fat.
How much fat is good?
A healthy fat diet that includes mono and polyunsaturated fats is essential during training and competition. It is recommended that an acceptable range for total fat intake is 20 - 35% of your daily calorie intake, with saturated fats providing no more than 10% of the total energy consumption.
Get to understand the foods you consume for better health but don't tackle weight loss by simply cutting out all fats!