No Fat Diet? Are All Fats Healthy Now? We Break it Down Below
Dakota Howe, B.S. in Food and Nutrition
You have probably heard many times before that eating low fat or fat free foods contributes towards good health. For decades, doctors and dietitians have advised people to pursue a diet low in fat in order to reduce their risk for heart disease and weight gain – this is how the “fat free” and “low fat” fads began. American consumers have been under the impression that consuming foods high in fat leads to negative health effects such as heart disease and weight gain. However, fat is not a substance that should be feared and more importantly, eating fat will not make you fat. The three macronutrients - protein, carbohydrates and fat - each play an essential role in the functions of the human body1. Often times, fat gets a bad reputation because people are under the impression that if they eat fat then it will get stored as body fat - this is not the case. The only way that eating fat will cause an increase in weight gain is if it is consumed in excess. This holds true for both protein and carbohydrates as well. For example, if you consume too many carbohydrates, your body will metabolize what it needs and then the rest will be stored as body fat. Additionally, the only way that eating fat will have any negative health effects is if you eat an excess amount of unhealthy fats.
Consuming fat is a necessary component in our diets and it serves several functions within the human body. In addition to contributing to biological functions in the body, healthy fats also offer a number of unique biological functions and health benefits:
- Provides the body with energy by breaking down into glucose when glycogen stores run out
- Allows the body to properly absorb fat soluble vitamins A, D, E and K
- Protects the major organs, nerves, tissues and bones by providing us with insulation and helping us to maintain proper body temperature
- Plays a key role in hormone regulation as well as brain health, structure and function
- Helps to maintain healthy hair, skin and nails2
- Decreases the risk of heart disease and stroke and improves blood cholesterol levels by increasing HDL levels (good cholesterol) as well as decreasing LDL levels (bad cholesterol)
- Acts as an anti-inflammatory, reducing inflammation in the body and helping to treat and prevent rheumatoid arthritis and some cancers
- Helps to maintain blood glucose levels and prevents insulin spikes
- Improves brain health and may help reduce the risk and prevent the onset of Parkinson’s and Alzheimer’s Disease
- Aids in weight loss and weight maintenance by providing feelings of fullness2,5,6,7
It is important to remember that not all fats are created equal and that certain types of fats are better for us than others. The different types of fats are saturated, unsaturated and trans fats; when consumed, each of these fats reacts differently in the human body. The difference between these fats has to do with the length of the fatty acid chain and the number of double bonds in each fatty acid chain. Unsaturated fats such as olive oil are typically found in plant based products and are liquid at room temperature and saturated fats such as butter are found in animal products (aside from coconut oil) and are solid at room temperature.
The two kinds of unsaturated fats are monounsaturated fat, which has one double bond between the carbon and hydrogen atoms on the fatty acid chain and polyunsaturated fat, which has more than one double bond between the carbon and hydrogen atoms on the fatty acid chain. Unsaturated fats are plant based fats that can be found in a number of foods. Some examples of monounsaturated fatty acids are olive oil, olives, peanut oil, peanuts, canola oil, avocados, seeds, nuts and nut butters; on the other hand, salmon, mackerel, sardines, flaxseeds and chia seeds are examples of polyunsaturated fatty acids. Consuming monounsaturated fatty acids provides the body with a number of benefits such as lowering levels of bad LDL cholesterol, reducing the risk of heart disease and stroke, promoting healthy weight loss and helping to alleviate the pain of rheumatoid arthritis7.
One of the most common types of polyunsaturated fats are Omega-3 fatty acids. Examples of foods that contain Omega-3 fatty acids are salmon, chia seeds, walnuts and avocados are rich in omega-3 fatty acids. These fats support brain health and cognitive function and may help reduce the risk of dementia. Additionally, omega-3 fatty acids have been shown to raise HDL levels (the good cholesterol) and decrease LDL levels (the bad cholesterol) while at the same time reducing inflammation in the body which is a major root cause of several harmful diseases and conditions such as arthritis8.
Trans fat, on the other hand, is a manmade fat that is created by transforming healthy unsaturated vegetable oils into solids through a process called hydrogenation. Hydrogenation, simply put, is when vegetable oil is heated with hydrogen and a metal catalyst, which causes more hydrogen atoms to add onto the carbon chain. This process is done to prevent foods from going rancid and greatly prolongs their shelf life5. However, trans fat is an unhealthy fat and should be avoided. The consumption of trans fat causes a decrease in HDL (the good cholesterol) and an increase in LDL (the bad cholesterol) along with increasing inflammation in the body and the risk of heart disease and cancer5,6. You can avoid trans fat by reading the ingredient listing on food labels and staying away from foods containing the ingredients “hydrogenated” or “partially hydrogenated” oil.
The recent recommendations for the consumption of saturated fat and its effects on the human body have been controversial. Saturated fats are fatty acid chains that are saturated with hydrogen atoms, meaning that each carbon atom in the fatty acid chain is attached to a hydrogen atom. The reason that saturated fats differ from unsaturated fatty acids is because those are broken up with one or more double bonds between the hydrogen atoms. According to the USDAs 2015-2020 Dietary Guidelines for Americans we should:
- Avoid trans fat
- Limit saturated fat to less than 10 percent of calories a day
- Replace saturated fat with healthier monounsaturated and polyunsaturated fats
However, recent studies have found that there is no concrete evidence showing that consumption of saturated fat has a direct correlation with increased risks of cardiovascular disease and coronary heart disease3, 9. Research suggests that unprocessed saturated fat coming from organic and pasture raised cows can contribute towards a healthy diet. In fact, replacing highly processed foods that are high in refined sugar with healthy sources of fat has been shown to have a positive impact on blood glucose and cholesterol levels4. Sources of healthy saturated fats include foods such as butter, milk, cheese and yogurt that come from high quality grass fed cows.
Moreover, when cooking with high heat it is better to use saturated fats such as ghee, lard and coconut oil instead of unsaturated fats coming from vegetable oils. This is because saturated fats have a higher smoke point, making them more resistant to oxidative damage which can have harmful effects on the body4.
It is beyond doubt that the consumption of fat plays a key role in a healthy diet. Not only do we need fat for our bodies to execute their biological functions but it also offers a number of additional health benefits as stated above, and not to mention…fats tastes good! Try these simple ways to incorporate healthy fats into your everyday diet: add nuts or nut butters into oatmeal, use slivered almonds in place of croutons, bulk up your salad with avocado and hard boiled eggs, mix almond butter into yogurt made from grass fed cows or add a tablespoon of chia seeds into smoothies. Most importantly, remember that just because something is fat free or low fat, does not mean that it is healthy. Aim to purchase products that contain high quality, clean sourced healthy fats5.
- 6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551118/