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Shifting the Fatty Acid Ratio


Submitted By Amy Sercel MS RD CD

Edited By Marcia Bristow MS RDN CSSD CD

From boxes of cereal to frozen dinners, the food we eat today is definitely not the same as the food our ancestors ate.  One of the most striking differences is in the types of unsaturated fat we eat.  While our ancestors used to eat about an equal amount of omega-3 fatty acids and omega-6 fatty acids, today we eat between 10-20 times more omega-6 fatty acids than omega-3’s.  Today’s foods contain more omega-6 fatty acids than they used to because food processing methods have changed.  Omega-6 fatty acids are found in corn, cottonseed, and soybean oils, which are common ingredients in packaged foods.  At the same time, livestock is raised on a diet of grains, corn, and soy, which results in meat and dairy products higher in omega-6 fatty acids. This dietary shift may be an underlying cause of weight gain, heart disease, and diabetes.1–3

Omega-3 and omega-6 fatty acids are both unsaturated fats that are essential for health.  Your body can’t make them, so you need to get them from food.  You’re probably familiar with omega-3’s because of their reputation for reducing the risk of heart disease.  They’re found in olive oil, canola oil, flaxseeds, walnuts, chia, and cold-water fish like salmon.2 When there are more omega-6’s than omega-3’s in your diet, omega-6 fatty acids will replace omega-3’s in your cells.2 Unfortunately, omega-6’s are more likely to become damaged than omega-3’s, which can lead to inflammation, increased blood pressure, and heart disease.1 Omega-6’s also promote the storage of fat throughout the body and in the liver, potentially resulting in weight gain and decreased liver function.1,3

The anti-inflammatory properties of omega-3 fatty acids appear to counteract the negative health effects of omega-6’s.  In one study, women with more omega-3 fatty acids in their cells were less likely to gain weight after ten years.2 Additionally, people who took daily 3-gram supplements of omega-3 fatty acids had a smaller waist circumference and lower blood pressure than those who did not at the end of a 20-week study.4

If you’re interested in shifting the ratio of unsaturated fatty acids in your diet, start by replacing some sources of omega-6 fatty acids with omega-3’s.  It’s important not to eat more calories than you need, especially if you are trying to lose weight; eating more calories from foods high in omega-3 fatty acids will still result in weight gain unless you reduce calories from another type of food.  Try snacking on some fruit and walnuts instead of a processed food.  You could also look for grass-fed beef instead of beef raised on grains, and eat cold-water fish once or twice per week.1 Combining these changes with daily physical activity is a great step towards weight loss and a healthier lifestyle.


  1.  Balancing Act. http://www.todaysdietitian.com/newarchives/040113p38.shtml. Accessed November 15, 2016.
  2.  Simopoulos AP, DiNicolantonio JJ. The importance of a balanced ω-6 to ω-3 ratio in the prevention and management of obesity. Open Heart. 2016;3(2):e000385. doi:10.1136/openhrt-2015-000385.
  3.  Simopoulos AP. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity. Nutrients. 2016;8(3):128. doi:10.3390/nu8030128.
  4.  de Camargo Talon L, de Oliveira EP, Moreto F, Portero-McLellan KC, Burini RC. Omega-3 fatty acids supplementation decreases metabolic syndrome prevalence after lifestyle modification program. J Funct Foods. 2015;19:922-928.

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