Dietary fat is a topic close to my heart (and probably every woman’s too). For years, I avoided it like the plague….low fat yogurt, zero fat milk, low fat cheese, lean meats etc….and followed the age old advice that fat will make you fat. Well I was incredibly wrong and it was only when I started to study how the body works and how hormones work. I hope to impart some of that knowledge to you in this article but if you only read this paragraph just know that fat won’t make you fat, nor will it mess up your aesthetic goals.
The job of the body is to store fat and it is really good at adapting in order to make this happen. Your body is build to help you survive and wants to have a constant source of energy ‘just-in-case’ – it couldn’t care less if you want to be 8% body fat or fit into those size zero jeans. Whatever work/exercise you choose to do, your body will try to complete this with as little amount of calories as possible. It goes back to primal instinct where from an evolutionary point of view, our bodies are set up to go for long periods of time without food so you needed energy reserves to survive without it until someone hunted down the next meal.
Despite big changes in our priorities and lifestyles (food is now plentiful, we no longer live in tribes, we have abundant supplies of natural resources at our peril etc) our primal instincts remain so you have to be smart if you want to change your body (By the way, from an exercise point of view, the smart tactic is to choose constantly varied, functional movement and challenge your body daily)
From a diet POV, eat dietary fat. The body is constantly adapting based on the food we eat and the exercise we do. If you eat carbs all the time, your body will become efficient at burning carbs efficiently AND also storing the excess just as efficiently (for a rainy day….which in our case never comes because we don’t have to worry about our next meal).
Eat lots of (good) dietary fat and? Well I discuss this below but the short hand answer is that you become more efficient at burning fat and your body is also fully equipped to balance your hormones (most of which are made from fats). If this is enough for you – scroll to the bottom for some good sources of fat because the type of fat that you eat is more important than the amount of fat.
Fat is not bad for you.
This whole craze actually began in the 1970s based on flawed research and since then we have only continued to get sicker and fatter. So basically when it comes to low-fat diets, we totally missed the boat. Let’s start by breaking it all down a bit (skip this if science is not your thing). Fat is the most dense source of energy of the three macronutrients with 9 Kcal/gram. This makes it more satisfying. When we talk about fat, we in fact mean fatty acids, which are chains of carbon and hydrogen atoms (Every fat, plant or animal, is made up of the same raw materials).
Dietary fats are classified in two ways:
- Chain length:
- Short chain (2-6 carbon atoms)
- Medium Chain (8-12)
- Long chain (14-22)
- Saturated: A fatty acid is saturated when all available carbon bonds are occupied by a hydrogen atom. What? Basically this means that every link in the chain is secured. This is why saturated fatty acids are more chemically stable (unreactive) and do not spoil (go rancid) when exposed to air, light and heat. Fats which are high in SFAs (butter, lard, palm and coconut, etc) are solid at room temperature. As well as being found in animal fat and tropical oils, your body makes saturated fat from carbs.
- Monounsaturated: These dietary fats have one double bond in the form of two-carbon atoms double bonded to each other and, therefore, lack one hydrogen atom. What.? They are more reactive than saturated fats and liquid at room temperature. Your body can make monounsaturated fat from saturated fats and use them in a number of ways. They too don’t go rancid easily e.g. olive oil as well as oils from almonds, pecans, cashews and avocados.
- Polyunsaturated: These dietary fats have two or more pairs of double bonds and, therefore, lack four or more hydrogen atoms. This basically means they are very unstable and susceptible to damage by light, heat and air. The two most common types of polyunsaturated fat found in our diet are omega-3 and omega-6 fatty acids. We cannot make these fatty acids and hence they are called essential. Other sources include plant oils, seeds and nuts.
All dietary fats and oils, whether of animal or vegetable origin, are some combination of saturated, monounsaturated and polyunsaturated fatty acids.
Main Functions of Dietary Fats:
- Storage as triglycerides in adipose tissue – i.e. fat storage around the body
- Structural Molecules: Lipids play a major part in all membranes, both surrounding and within cells. Nerve cells are especially high in fats with up to 60% of brain tissue being composed of fat.
- Fat is used to make lipoproteins, eicosanoids (compounds involved in synthesis of hormones), steroid hormones (oestrogen, testosterone for e.g.), bile salts.
- Fats and oils transport fat-soluble vitamins and antioxidants around the body to their required destination
- Fat provides heat insulations under the skin, protects tissues and organs from physical damage.
Dispelling Some Myths:
 Eating Fat will Make You Fat
Well Nope – In a massive study that included tens of thousands of people, women who follow such a diet for 7.5 years end up weighing only 0.4kg (1 lb) less than women eating the standard western diet. There is also no effect on heart disease (1, 2.)
Sugar is the true culprit, and not fat.
As Dr.Hyman writes here (2.)
“This makes perfect sense — because insulin does two things: It stimulates hunger It is a fat storage hormone, which makes you store belly fat After you eat a high-carbohydrate meal, your insulin spikes and your blood sugar plummets — making you very hungry. That is why you crave more carbs, more sugar and eat more the whole day.”
 Eating Fat will Give you High Cholesterol
Cholesterol is a waxy, charming lipid that the body produces on its own and is found in every cell’s membrane and our blood plasma. It has multiple jobs including insulating neurons, building and maintaining cellular membranes, metabolizing fat soluble vitamins, producing bile, and kick-starting the body’s synthesis of many hormones, including the sex hormones. First off, the simple fact is that without cholesterol, you would die. Cholesterol is so important that your body (i.e. the liver) will make a certain amount every day. In addition to this, the liver has feedback mechanism to regulate this production process relative to the amount of cholesterol you actually eat daily. Second, cholesterol in food does not necessarily equate to cholesterol in the blood. Why eat cholesterol rich foods when the body will make them anyway? – Simples – You make the job easier. In addition, cholesterol rich foods like eggs, seafood, butter all come packed with other nutrients like vitamins A, D, E, K and other hormone building substances. As Liz writes in her book Eat the Yolks (3) –
“I don’t think Mother Nature would intentionally package the good stuff with the bad stuff.”
Again Dr.Hyman’s article here (6) sums it up brilliantly:
“We know what causes the damaging small cholesterol particles. And it isn’t fat in the diet. It is sugar. Sugar in any form or refined carbohydrates (white food) drives the good cholesterol down, cause triglycerides to go up, creates small damaging cholesterol particles, and causes metabolic syndrome or pre-diabetes. That is the true cause of most heart attacks, NOT LDL cholesterol.”
The type of dietary fat that you eat is more important than the amount of fat – Transfats and hydrogenated fats promote abnormal cholesterol whereas omega 3 and fats and monounsaturated fat actually help improve the type and quantity of cholesterol. Without getting too much into it as this ‘myth’ deserves a blog post of its own, I must point out that your total cholesterol levels are not a clear indicator of what is actually going on. You need to consider other markers:
- Your levels of HDL “good” cholesterol vs. LDL “bad” cholesterol
- Your triglyceride levels
- Your ratio of triglycerides to HDL
- Your ratio of total cholesterol to HDL
Your blood cholesterol is managed by your body in response to what is going on inside and out – i.e your cholesterol may rise for many reasons such as in response to systemic stress, poor diet, poor lifestyle choices, thyroid issues, other health problems, healing from surgery or dental procedure, rebalancing which takes place after weight loss (page 59, Eat the Yolks – reference no.3 @bottom). Cholesterol also rises with age as our bodies begin to require more support for healing and fortification. Heart disease is not only about cholesterol and you will find a tonne of information about tests to look at here (6).
 Eating too much Saturated Fat is Bad for You.
This notion is really deeply ingrained in our brains – that artery clogging fat, the evil fat, the fat that kills….jeez saturated fat has had a rough time with all the name calling! The demonization of dietary fat began in the 1950s with Dr Ancel Keys and his 7 Countries Study. Keys published a paper comparing fat intake and the cause of heart disease mortality and this paper resulted in the following assumption being made:
If saturated fat raises cholesterol (A causes B) and cholesterol causes heart disease (B causes C), then this must mean that saturated fat causes heart disease (A causes C).
However, despite this correlation appearing between Seven Countries, Keys actually had looked at Twenty-Two Countries and just omitted the data that didn’t match (and in fact demolished this whole idea in the first place). You can review the graph here (7), but what I will say is that the correlation is almost non existent as far as I can see – in fact it barely appears on the graph.! Key’s hypothesis (called the “diet-heart hypothesis”) was based on assumptions, observational data and animal studies. And furthermore, as we learn in school: Correlation does not mean causation.
Well anyway long story short, Keys became an icon, made the front pages and his diet-heart hypothesis then turned into public policy in 1977. I wont dwell anymore but if this interests you, I would seriously suggest checking out THIS POST. (Denise’s blog is invaluable when it comes to breaking down statistics…….in fact her series on ‘The China Study’ is also AMAZING in my opinion (you may need to give up the social life for a bit to get through all the information!!!!) ).
Ok where was I!! Oh yes saturated fat….As explained above, SFAs are shelf-stable, resistant to heat damage, and essential to many bodily functions. In fact, roughly half of our cell membrane structure is composed of saturated fat. When and if you are an efficient fat-burner, saturated fat is actually a brilliant source of energy. Again I wont dwell on all of this yet (individual blog posts on each of these myths will come in due course) but just to re-iterate the phrase already mentioned above: The type of fat that you eat is more important than the amount of fat. And as a final stab, Mark also highlights (7):
“The justification for the anti-saturated fat campaign that has raged on for half a century is largely baseless. Even if saturated fat does increase (large, fluffy) LDL, it increases protective HDL right along with it, and cardiovascular mortality has never been explicitly demonstrated to increase with saturated fat intake. Several studies have been attempted and – though their results were inconclusive – supporters repeatedly cite them as evidence for the connection.”
Why do all these trains of thought continue to penetrate and saturate the media stream you say? Well I think this article (4) puts it nicely by saying the sad reason is that corporations pay millions each year for this so that people continue to buy their products. Hard to believe but it’s true – unfortunately our health comes second best to the $$$ signs. Even the food pyramid (12) was not created for the sake of public health alone – the base went to the biggest bidder (the grain industry) followed by the dairy industry….unfortunately money rules and for this topic let me direct you to this book.
Hold your horse right there pall and put down the bacon, I’m not finished quite yet. There are some fats which deserve a warning.
Basic advice: Yes transfats exist in nature, it’s the artificial ones we should be worried about! Ok so think hydrogenated fats i.e. margarine, shortening….Producers faced the problem of needing to turn a liquid oil into a solid so the solution was to change the molecular structure of the fatty acids in the oil or in more technical terms – the double carbon bonds were broken by inserting hydrogen atoms which results in a structure similar to that of saturated fats. And remember that these fats are solid at room temperature. Sounds simple enough. However, there is an added challenge that if this process was applied to every double carbon bond in this oil, the result would be a very solid structure – i.e. very hard and very stable.
So, producers have to stop the process before it is ‘complete’ and the resulting product is the transfats we know and see in the shops. What’s the problem with these fats.? Well they do exist naturally in meat and dairy products (also referred to as CLA) but the problem is that the processed type of transfat are the wrong shape, and so cannot be safely or effectively incorporated into normal metabolic processes and structures of the body. They place a strain on the liver and are known to be a significant risk factor or as Mark puts it (9):
“The trans fats go on to incite havoc in cell metabolism. Research indicates trans fats cause comparatively more weight gain than the same diet with monounsaturated fats and a redistribution of body fat tissue to the abdominal area, the riskiest place to carry extra padding. Additionally, they’re associated with inflammation and atherosclerosis”
What food may contain this dietary fat? Biscuits, crackers, cakes, muffins, pie crusts, pizza dough, breads such as hamburger buns, cheaper margarines, vegetable shortening, cooking chocolate, pre-mixed cake and pancake mixes, chocolate drink mixes, fried foods, including doughnuts, chips, chicken nuggets, taco shells, frozen dinners, snack foods, including crisps, sweets, packaged or microwave popcorn.
2. Polyunsaturated Fats and Cooking
These fats are explained up above so scroll back up for definition. In Short: there’s good and bad news here – Eat oily fish, seaweed, flaxseeds.
Avoid vegetable and nut/seed oils, especially for cooking.
Some of these fats are essential (i.e. our body cannot make them and we must eat them) such as the well-known Omega-3. The problem is when these fats become damaged…or rather oxidised. Then it’s a whole different story. Oxidation or damage happens when these oils are exposed to light, heat and air (especially heat). Once damaged, these oils produce the ‘bad guys’ called free radicals which wreak havoc in our bodies – They affect our cell membranes, DNA/RNA and put a strain on our organs all of which may eventually cause skin disease, liver damage, suppressed immune system.
As Diane so well explains (10):
“Oxidized or rancid oils in the body enter and cannot be biochemically understood as food. They enter and are more like a PLASTIC in the body, or a toxin. Our body does not metabolize toxins but rather STORES them – in our fat cells. This leads to inflammation. Inflammation is a key player in many chronic diseases, weight gain, weight loss resistance, general feeling of fatigue, pain and lethargy, joint pain, etc.”
Practical advice: Avoid vegetable and seed oils when it comes to cooking. These are difficult to extract from the plant/seed and/or usually undergo heavy processing to create the finished product. Instead look to coconut oil or other saturated fats to cook with because as I mentioned earlier, these are stable and do not chemically change composition when heated.
For e.g. Canola oil (10):
Rapeseeds + high heat processing with hexane (a chemical solvent) = a grey, awful smelling, non-smooth oil. This grey, awful smelling, non-smooth oil is then chemically bleached and de-gummed bleached and de-gummed, awful smelling oil is then chemically deodorized bleached, de-gummed, chemically deodorized oil is then dyed yellow and bottled in plastic
For the full process, check out the ‘How it’s made video’ industry link.
Look for organic, extra virgin or cold pressed oils when it comes to olive oil, sesame oil, nut oils, avocado oil and nuts & seeds in general. Also buy oils in dark bottles where they are more protected from natural light.
Everything you could ever hope to know about fat is HERE (11).
3. Omega 3:6
Finally, a note on the two famous polyunsaturated fats; Omega-3 and Omega-6.
Omega-3 is known for its anti-inflammatory properties and fat burning benefits whereas Omega-6 has earned a bit of a bad reputation as it is also often known as a pro-inflammatory fat. Well the truth is, this is not a bad thing. In fact, we need to consume both as they are essential i.e. our body cannot make them so we must obtain then in our diet.
The problem arises when it comes to both quantity and quality.
We are supposed to consume an even 1:1 ratio of Omega 6:3 but people today are often more in the category of 20:1 (that’s 20 omega-6 to every 1 omega 3) – I think it is quite obvious that this means there is too much inflammatory vs anti-inflammatory dietary fat being put in the body. Not good.
You might refer back above where I spoke about polyunsaturated fat and how easily damaged they are. Well Omega 6 is also a polyunsaturated fat and is found in non-other than the heavily processed nut, seed and vegetable oils we so liberally use in our cooking (as well as found in most fast food and restaurants).
So again you see the problem – consuming not only too many inflammatory fats, but also consuming them when they are already damaged and so of more harm than good.
Practical advice: The above should explain why we are often told to eat more oily fish and why fish oil is so popular – i.e. people are eating too much omega 6 and the two solutions are: Increase Omega 3 Reduce Omega 6 intake (point 2 has all the advice you need)
Some sources of Omega 3:
- Animal Sources: Fish & Seaweed (herring, sardines, mackerel, trout, salmon, anchovy, tuna, shrimp –
- Vegetarian Sources: Seaweed, hemp, chia seeds, flaxseeds)
Phew…right I think that’s enough – let’s look at some sources of dietary fat in general….
- Nuts—walnuts, almonds, pecans, macadamia nuts (**Peanuts are not technically a nut, they are a legume)
- Seeds—pumpkin, sesame, chia, hemp
- Fatty fish, including sardines, anchovy, trout, mackerel, herring, and wild salmon that are rich in omega-3 fats
- Extra virgin olive oil
- Animal Fat – look for grass-fed, organic where possible.
- You can even eat saturated fat like extra virgin coconut butter, which is a great plant-based source of saturated fat that has many benefits.
So make yourself a coffee, a 3 egg omelette with all the yolks and a side of avocado. Your body will thank you.