Fat is a tricky one. Out of the three macro-nutrients, it is probably the most difficult to get our heads around. How much should we eat?…What’s the difference between omega-3, polyunsaturated fats, trans-fats and saturated fats?…Do we even need fat?…Wait, there’s omega-6 fats too?…and, what the hell are fatty acids?… We know protein is good for muscle growth and a myriad other health benefits, and hopefully even the most pro-caveman dieters among us know that carbohydrates are necessary for giving us very accessible energy.
Fat, however, has an immediate negative connotation to it. I mean, we are what we eat, right? Doesn’t that mean eating fat will make us…fat? Not if we eat well. And the bottom line is – we need it.
Fat as an Energy Source
Calories: it’s like a swear word these days. If a food item is 200 calories, and 50 of those calories is from fat, people automatically think they are going to put weight on in the form of 50 mystery units of fat. Actually, a calorie is a unit of energy.
Fat is a source of that energy, and guess what else: it’s more than twice as concentrated a form of energy than protein and carbohydrates. For every gram of fat, we get 9 calories. The same weight in protein gives us 4 calories, as do carbohydrates. Fat, therefore, is a denser energy source than carbs and protein combined, which in turn means that fat goes further.
It is important to remember that carbs are still more efficient than fat even though we need to eat more volume of carbs to get the same energy potential.
The myth of avoiding carbs is actually disproved by this fact alone. You could eat more than twice the amount of carbohydrate to fat to get the same energy potential and it would be more available and efficient to use when we exercise.
Now, we use fat better when we are at about 60-65% of our maximum effort, which for most of us falls within the category of aerobic exercise. Because we need oxygen to use fat as the main source of our fuel, when we switch to more intense, anaerobic exercise, carbohydrates become the main source of energy. Even then, we use quite a lot of fat.
At lower intensity levels, a greater proportion of fat compared to carbohydrates is utilized but that doesn’t mean more fat is burned. At higher exercise intensity, the volume of fat utilized increases but at a lower proportion to carbohydrates.
Due to the greater energy expenditure, higher intensity exercise still burns a greater volume of fat than lower intensity exercise over an equal time frame.
This is important to note if weight loss is the athlete’s goal. A lot of people exercise at very low intensity thinking they are losing more fat. Their ratio of fat to carb usage is indeed higher but the volume is much lower. The fact is, they should be going for at least 65% of their maximum output for the same period of time to see better results.
Essential Fatty Acids
As with the essential amino acids (see protein section), our bodies cannot synthesize essential fatty acids yet they are required for metabolic function. Omega-6 (Linoleic fatty acid) and Omega-3 (Linolenic fatty acid) must therefore be sourced from our food or supplements.
Omega-6 fatty acids are polyunsaturated, which means their carbon chain has more than one double-bond included (those with none are called saturated fats, and those with just one double-bond are monounsaturated). The “6” part means this particular polyunsaturated fatty acid has its last double bond six carbons away from the end of the chain. Omega-3 fatty acids – you guessed it – have their final double-bond just three carbons from the end of the chain.
Omega-6 fatty acids are essential for healthy skin and we need about 16 grams a day. Omega-3s are necessary for neural function and growth and 2 grams per day will probably be enough.
Both can be sourced from vegetable oils like canola oil or fish oils in the form of capsules that can be taken like a pill. Recently, Omega-3 fatty acids have been elevated to sports supplement status given their potential ergogenic benefits to athletes in addition to the list of general health positives. These benefits include:
- better partitioning of nutrients and oxygen to muscles
- anti-inflammatory behaviour (speeding post-workout recovery)
- enhanced aerobic metabolism
- increase in a growth hormone associated with anabolic effects (muscle growth and recovery)
- decreased chance of blood clot formation (reducing risk of heart attack)
Eating more fat is not the message here. Simply altering the type consumed will help. For athletes, for example, cold water fish such as salmon should be on the menu to increase their proportion of omega-3s. The ratio of omega-6 to omega-3 in our diet should be 3:1. In western culture, the majority of people are not adhering to this and are risking their health as a result. Here are some more sources of the essential fatty acids:
Sources of Omega-6 Fatty Acids
- Sunflower oil
- Soybean oil
- Sesame oil
- Hemp oil
Sources of Omega-3 Fatty Acids
- Eicosapentaenoic acid (EPA), from fish
- Docosahexaenoic acid (DHA), from fish
- Alpha-linolenic acid (ALA), from:
- seeds and nuts (inc. walnuts and brazil nuts);
- flaxseed (and its oil);
- soybeans (and its oil)
In conclusion To wrap this business of fats up, all we can really do is try and be better with our diets. It sounds weak, but it’s true. If an athlete wants to be at their best, or even just someone trying to live a healthier lifestyle, they will benefit from changing their diet from that all too habitual western routine saturated in, well, saturated fats.
A more sustainable and, yes, life-preserving option exists. With a reduction in total fat consumption and a switch to the essential variants like omega-3 and omega-6, the benefits will far outweigh the loss of fries and sandwich meats.
Those athletes I mentioned can afford to source more of their energy from carbohydrates instead and keep themselves healthy from the inside out.