Fabulous Fats

Fat is an essential part of a well-balanced diet.  Remember variety is key and fats are no different.  Make sure to consume a variety of fats with the majority being from nuts, fish, fruits, and vegetables.  It can seem daunting to obtain 50-60% of your calories from fat but remember there are more than double the number of calories in a gram of fat than in carbohydrate or protein, with each gram of fat containing 9 calories.  The chart below shows common foods and their fat contents.  Important factors to consider when choosing healthy fats are the Omega 3 to 6 ratio, if they are unsaturated or saturated, their smoke point and processing methods used to extract oils.   Whole food forms of fats are typically the most stable and less likely to produce free radicals due to oxidation.  

Below you will find a sample combination of foods to obtain 50% of calories from fat (110 grams) for an average 2000 calorie meal plan:
 
1 whole avocado:  30 grams
1 tbsp of almond butter:   8 grams
1/3 cup of hummus:  8 grams
1/3 cup almonds:  23 grams
1 tbsp of olive oil: 15 grams
2 ounces of dark chocolate:  20 grams
Total:  104 grams of fat
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Omega 3 to 6 Ratio

Fats (or lipids) are composed of fatty acids.  Our bodies are able to synthesize many of the fatty acids it needs, but there are some that we must obtain from our diet, such as Omega 3 fatty acids.  Most diets are high in omega 6 fatty acids and low in omega 3 fatty acids.  An optimal ratio of omega 6 to 3 fatty acids (around to 2:1) is believed to reduce inflammation, which is a driving force of chronic diseases.  

Below you will find serving sizes of fats and a chart showing the ratio of fatty acids in different fats.  As you can see corn, soy, cottonseed, and sunflower oil are all very high in omega 6 fatty acids while coconut oil, butter fat and olive oil are low.  

Saturated and Unsaturated Fatty Acids

​​Saturated fats are solid at room temperature and unsaturated fats are liquid at room temperature.  The number of double bonds a fat contains determines whether it is saturated or unsaturated.  If a fat has multiple double bonds it is a polyunsaturated fat, if it contains only one double bond it is a monounsaturated fat and if it contains no double bonds it is a saturated fat. 
 
Why is this important?  The more double bonds a fat contains the more unstable it is.  This is due to the fact that free radicals (aka reactive oxygen species) can bond to the double bonds causing oxidative stress.  An unsaturated fat contained in a food is more stable, and therefore healthier, than an unsaturated fat that has been highly processed using heat and/or chemicals such as hexane. 
 
A good example of this would be flaxseed oil.  The oil in the flaxseed is more stable and a healthier option, especially since it contains an optimal ratio of omega 3 to 6 fatty acids.  However, if removed from seed, heated and treated, and placed on a shelf it becomes oxidized and contains higher amounts of free radicals which promote inflammation.  Often fat will have an off odor when this occurs, which is commonly referred to as rancid. 
 
Fish oils are another example of polyunsaturated fatty acids that can cause oxidative stress if not handled properly.  Consuming omega 3 fatty acids in their whole food form from fish such as salmon and trout is optimal.  However, many individuals choose to take a supplement instead.  Caution is needed when choosing a fish oil supplement because if the product has not been processed or handled properly it can cause more harm than benefit.  Make sure to purchase from a reputable company that conducts third party rancidity testing and purity testing.
 
Storing oils in a cool, dark location will help slow the oxidation process.  Freezing or refrigerating an oil will keep if fresher longer. 
 
The chart on the following page shows the amount of saturated, monounsaturated, and polyunsaturated fatty acids in various types of fats. Choosing a fat with minimal polyunsaturated fatty acids is optimal.  Remember to also consider the ratio of omega 3 to omega 6 fatty acids.  

Smoke Point of Fats

​The smoke point, or burning point, of a fat is the temperature at which the oil will begin to burn and produce a visible smoke.  Not only does the cause an off taste and smell, it also destroys nutrients and produces free radicals. 
 
By learning common smoke points of fats, you will be able to determine their best culinary application.  If you are cooking at higher temperatures, i.e. frying or roasting, you would want to use an oil with a high smoke point.  Whereas for a salad dressing or a food that is slightly heated you could use olive oil or butter.  See chart below for average temperatures of various cooking methods.   

​The following page list common fats and their smoke point.  If you mix oils, you would use the oil with the lowest smoke point as a guide for appropriate cooking methods.  Refined oils generally have a higher smoke point than unrefined oils, however, they are also generally lower in nutritional value.  Also pay close attention to the processing methods, cold pressed oils that do not use high heat and chemicals, such as hexamine, for fat extraction are recommended.