Fortunately, this particular myth has been addressed enough that many of our clients know that the type of fat or oil they consume is more important than the quantity. The low-fat diet myth perhaps originated from good outcomes when people cut out the most unhealthy and, at the time, most ubiquitous fats.
We won’t get into what is healthy fat and what isn’t because such information is readily available online and reliable. The AHA has good information on the topic of healthy vs unhealthy fats.
What we want to address here is that fat is quite important and rarely the cause of atherosclerosis or obesity, even though these two conditions are often associated with fat intake.
It plays an important role in satiety and vitamin absorption. Without healthy fats, the body will have a harder time absorbing and holding on to nutrients.
There is a difference between low-fat and non-fat diets or what some might call a very fat-restrictive diet. The low-fat diet myth claims that with lower fat intake, you have a lower risk of heart disease and lose weight. In fact, the opposite is true.
A dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women and achieved only modest effects on CVD risk factors.WHI Study
However, there are instances when a low-fat diet makes sense. And, of course, for anyone who benefits from a better calorie balance, it might make sense to cut out the most calorie-rich foods, such as oils and fats.
Our colleagues over at Mastering Diabetes are major proponents of a low-fat diet, and it makes perfect sense in their program. This isn’t to say that everyone with normal A1Cs should consume a low-fat diet.
The Source of Fat
Fats and oils end up being used interchangeably in our common vernacular. Arguments over whether seed oils, olive oil, or butter are good or bad are common. They often end in stalemates, and opinions tend to trump science.
At Heart Health Coach, we don’t believe there is any fat that is necessary for good health. Meaning you don’t need olive oil to be healthy or that coconut oil is a must for anyone who wants to prevent dementia.
However, if our clients are going to consume butter, we want them to obtain it from a good source. The same is true for any oil or fat.
Within species (like cows), the diet of the animal can impact the nutritional profile of the butter. Grass-fed cow’s butter, for example, often has a higher omega-3 fatty acid and vitamin K2 content than grain-fed cow’s butter.
When cattle are finished on pasture, the resultant meat and dairy products are higher in omega-3 fatty acids and have an improved omega-6:omega-3 ratio. Grass-based diets have also been shown to enhance total conjugated linoleic acid (CLA) isomers, trans vaccenic acid (a precursor to CLA), and antioxidants in beef.BMC Nutrition Journal
Low-Fat Diet Myth
The low-fat diet myth has led to egg white omelets, non-fat milk, and fat-free cookies. These dietary modifications are not only ultra-processed, but they also provide the person with a dietary intake profile that skews nutrient absorption.
When we meet with clients, we spend quite a lot of time on gathering a proper nutrient profile. We develop a diet risk score to help us make further dietary suggestions.
The PURE trial found that contrary to prevailing dietary guidelines, higher fat intake was linked to a reduced risk of mortality, while high carbohydrate intake was linked to an increased risk.
This isn’t to say that this trial is the end-all-be-all on this topic. It has plenty of limitations, but it’s safe to say that historically people have done well eating a well-balanced, nutrient-dense diet that included fats. It’s the quality of fat that might be in question in the low-fat diet myth.