Cooking Tips · Techniques

Fats in a Healthy Diet

In this final installment of my series of Cooking Tips on healthy cooking/eating, I want to discuss fats and oils and the place they play in healthy cooking.

Ever since the 1970s, fat has been proclaimed as the worst offender in our diets. However, we are finally beginning to realize that not all fats are bad and that sugar plays at least as big, if not larger, role in unhealthy diets. As I mentioned in a prior Tip, the fats that you want to limit and/or avoid are saturated fats and, especially trans fats. (I must mention that the recommendation to avoid all saturated fats is not totally without disagreement. For a scholarly review of this subject, see this article published in a 2018 issue of Nutrients.) Even with sugar, it is not all sugar you need to limit but what is called “added sugar” – the sugar that is not natural in the food.

You may have heard the terms “good fats” and “bad fats”. Bad fats are usually thought of as saturated (see above article reference) and trans fats. As I mentioned in a prior tip, trans fats are normally found in packaged and processed foods. Sources of saturated fats are:

  • Dairy products – butter, whole milk, yogurt, cheese
  • Meat products – lard, bacon, red meat, poultry skin

Good fats are:

  • Monounsaturated fats – found in olive oil, canola oil, peanut oil, avocados, olives & nuts.
  • Polyunsaturated fats
    • Omega-3 fatty acids – found in fatty fish, walnuts, chia seeds & flaxseeds.
    • Omega-6 fatty acids – found in vegetable oils (safflower, sunflower, oil and soybean) as well as sunflower seeds, pumpkin seeds and walnuts.

In the literature, there is some caution about omega-6 fatty acids based on the fact that the body can convert the most common omega-6 fatty acid, linolenic acid, into another fatty acid, arachidonic acid. The latter is a building block for molecules that can promote inflammation, blood clotting and blood vessel constriction. However, the body can also convert arachidonic acid into other molecules that calm inflammation and fight blood clots.

Most Americans eat more omega-6 fats than omega-3 fats, about 10 X more. Some will look at the ratio of omega-3 fatty acids to omega-6 fatty acids and advise us to cut back on omega-6 fats to improve this ratio. However, the problem is felt not so much to be an excess of omega-6 fats but a deficiency of omega-3 fats. So, you want to improve the intake of omega-3 fats but not decrease your intake of omega-6 fats. Here is a chart from Nutrition Action that breaks down oils in terms of saturated, polyunsaturated and monounsaturated content.

Apart from health, there are other considerations for choosing which oil you should choose for cooking. There is really no one all-purpose oil for culinary purposes. It depends on how you are going to use the oil and something called the “smoke point”. This is the temperature at which the oil starts smoking and breaking down. Therefore, some oils are better suited to higher temperature cooking. See this chart from Serious Eats on smoke points. Here are some recommendations for oils to have in your kitchen.

  1. A high-heat neutral-tasting oil – this is the type of oil you should reach for when you are doing high-heat cooking or in dishes where you do not want to taste the flavor of the oil. Examples include canola, safflower, sunflower, corn, grapeseed & peanut oil.

  2. Olive oil – there is a difference between light or refined olive oil and extra-virgin olive oil. The latter has a lower smoke point and is generally more expensive. Most of us recommend saving this extra-virgin olive oil for making salad dressings or for dishes such as dips where you want the flavor to come through. For other uses, use a less expensive and more refined olive oil. (Stay tuned for a Tip specifically on extra-virgin olive oils.)

  3. Specialty oils – if you cook Asian food, sesame oil is indispensable. Also, a nut oil such as walnut oil lends a wonderful flavor to nutty vinaigrettes. These are considered seasoning oils rather than cooking oils.

Oil does not last indefinitely and must be stored properly. Since heat and light can damage oil, store it in a cool, dark place. In that case, most oils can last up to a year. There are specific oils, though, that require refrigeration. Check the label but examples are grapeseed and nut oils. Some culinary experts recommend storing all your oils in the refrigerator. If you do that, some may thicken and you will need to let them sit out on your counter a few minutes to come to room temperature.

With this Tip, I bring my series on healthy cooking/eating to a close. I hope you found it helpful and it will be an impetus to improve your diet. Allow me to end with some advice with which I started this series. Get in your kitchen and cook more from scratch. Try to get away from processed and packaged foods. Just that one change will be a giant step in the right direction!