Is Fat Making Us Fat?
Over the past couple of weeks we have been looking into common diets like the Nordic and Ketogenic diet. Just last week we highlighted the fact that our society is addicted to sugar, all because the food industry blamed fats as a cause for cardiovascular disease. Because of this cover up we all lived by the simple dogma that fat makes you fat. Many products in the grocery store were modified to be low fat or completely non-fat. Our cheese of choice was light, and our mothers only served us skim milk, and yet, obesity has been on the rise since we were fed this big fat lie.
So what is happening here? Were we completely fed a handful of lies, or is there some truth to the last 40 years of food choices? This week we will be digging deeper into the idea that fat is making us fat.
What is fat?
Fat as a fuel source, or macronutrient, is the most calorie dense of the macronutrients. 1g of fat provides 9kcals (Cals), in comparison to carbohydrates and proteins, which provide 4kcals per 1g. This means that you only have to eat half as much fats in order to yield the same energy as carbs or proteins.
Fats are also crucial for the absorption of vitamins A, D, E and K. The fact that we were advised to limit our fats in the past is crazy knowing that we need fats in order to absorb such vital vitamins.
There are 3 main types of fats that we see in most food items. Saturated fats, unsaturated fats, and trans fats. They are given these names based on their molecular structure. Saturated fats are made up of a chain of carbons of which each is bonded to a hydrogen or carbon atom by a single bond. Unsaturated fats have double bonds between 1 or more carbon atoms. Trans fats are an altered form of the unsaturated fats, and their molecular structure is achieved by synthetically hydrogenating the chain. Each configuration of these fatty acid chains gets broken down, or metabolized, by the body differently.
All of this mumbo-jumbo chemistry talk can be seen in the following image:
Does fat makes us fat?
As was previously stated, each of these fats is broken down differently by the body. Without going into detail and boring you with more chemistry mumbo-jumbo, just know that the bonds between the carbons and the shape of the molecule, and how they molecules stack up against each other effect how they are broken down by the body.
It is at this point that we need to change the question because what makes us fat is simply a surplus of calorie intake in comparison to our calorie expenditure. With that said, proteins and fats serve many other purposes besides energy production so when we consume these macronutrients they get put straight to work and are less likely to be stored as fat. Carbohydrates, on the other hand, provide us with energy. So if we do not need the energy, we simply store it in our body’s fat cells for another time.
I digress – back to the real question.
So if they aren’t making us fat, why are they so bad?
Specific types of fats have the potential to be detrimental to our health, if consumed in large quantities and in combination with a sedentary lifestyle, smoking, drinking, and stress. Trans fatty acids, or simply trans fats, have been shown to increase our bad cholesterol, LDL, and lower our good cholesterol, HDL.
Yes, that’s right, good cholestrol. That is a topic for another blog.
So what about saturated and unsaturated fatty acids? Well it was long believed that the consumption of these would lead to an increase risk of cardiovascular disease and stroke. More recent research has shown that this is not the case.
Saturated fatty acids have actually shown no direct effect on increasing your risk for cardiovascular disease (CVD) and stroke, and combining saturated fatty acids with unsaturated fatty acids actually showed a 17% decrease in the risk for cardiovascular disease. With that said, saturated fats do affect the levels of LDL, or bad cholesterol, in our blood. So while researchers are not finding a direct increase in CVD risk, LDL is linked to risk factors associated with cardiovascular disease, and therefore saturated fats on their own should be limited in your diet.Health Canada recommends that you keep saturated and trans fats as low as possible, while maintaining healthy levels of mono- and polyunsaturated fats. A few examples of these are nuts and seeds, fatty fish, avocados, vegetable oils.
So Fat Doesn’t Make me Fat, but Trans Fats and Saturated Fats Just Makes Me Sick?
Research has shown that fats when consumed in combination with carbohydrates leads to unfavourable body composition. So fats alone are not contributing to weight gain, it is more about what you are eating your fats with. Other factors such as genetics and insulin sensitivity will also determine the effect of this combination of macronutrients.
If there was one clear culprit for what has caused the increase in obesity and cardiovascular disease in the last 30 to 40 years, it would be easy to deal with that issue. Unfortunately there are many other factors that lead to weight gain and cardiovascular disease, so trans fats, saturated fats, and carbohydrates cannot take all the blame.
While we all digest this reality, why not check out a few great resources on fats!