Fish Oil for Fat Loss – What Studies Show

The health benefits of fish oil for weight loss, fat loss, and managing inflammation are profound. Fats play a vital role in controlling inflammation as some fats are inflammatory and other fats, such as the essential omega-three fats found in fish oil, are anti-inflammatory. 

Inflammation and weight gain are indirectly connected as inflammation can contribute to insulin resistance which is an underlying cause of weight gain, prediabetes, and type 2 diabetes.

Disclaimer: This site contains affiliate links. As an Amazon associate, I earn from qualifying purchases.

One of fish oil’s benefits for weight loss is due to the ability of the body to reduce inflammation with the anti-inflammatory omega-three fats found in fish oil. While many studies show the positive effects of fish oil on overall health, including brain function, joint pain, and many other health conditions, it is still unclear whether there is a direct relationship between fish oil and weight loss. 

A meta-analysis of 21 studies found that while fish oil supplementation did not reduce body weight, but the intake of fish oil capsules was found to reduce abdominal fat and waist circumference. The increased abdominal fats put people at risk for fatty liver, insulin resistance, and diabetes. 

Another study in 40 obese or overweight individuals found that those who received omega-3 fats containing 1020 mg of EPA and DHA combined for 12 weeks while following a weight loss diet saw an increased reduction in abdominal fat mass.

Studies in mice showing the benefits of fish oil for weight loss

A study done in mice used a high-fat diet to promote fat accumulation resulting in raised inflammatory markers and causing insulin resistance and glucose intolerance.

The administration of fish oil to the very same mice reduced the harmful effects of the high-fat diet. The mice given fish oil had reduced body fat, improved insulin sensitivity, and reduced inflammation.

The adipose tissue stores excess fuel as fat plays a central role in the control of metabolism. Excess fatty tissue is associated with obesity (weight gain), type 2 diabetes, and metabolic syndrome.

Inflammation and fat accumulation are the primary causes of weight gain and insulin resistance.

Another study showed that the chronic overfeeding of a high-fat diet in mice caused increased body weight and fat accumulation.

Along with these mice developing more adipose tissue (body fat), they also developed an intolerance to glucose and insulin. They had higher blood glucose levels which are the symptoms of prediabetes. But they were able to prevent these exact conditions from developing by co-treatment with fish oil supplementation!

This study demonstrates the powerful benefits of taking fish oil for weight loss and preventing the development of insulin resistance.

Fat accumulation in adipose tissue leads to insulin resistance and inflammation due to overfeeding on a high-fat diet. With this information, it becomes easy to understand how to lose weight and reverse insulin resistance by using the power of an anti-inflammatory diet high in omega-three fats.

You may be wondering what makes fish oil and omega-three fats beneficial for weight loss when it was a high-fat diet used to induce obesity in mice.

The answer lies in understanding the various types of fat and their role in managing inflammation in the body because not all fats are equal, as you will soon find out.

Saturated fats in coconut oil, coconut cream, butter, cheese, and animal fats can be converted into a pro-inflammatory compound in the body called arachidonic acid. Saturated fats cause insulin resistance and increased insulin levels. High levels of insulin lead to weight gain.

Fish oil for fat loss

A meta-analysis of 21 studies found that while fish oil supplementation did not reduce body weight, the intake of fish oil capsules was found to reduce abdominal fat and waist circumference. The increased abdominal fat, in particular, puts people at risk for fatty liver, insulin resistance, and diabetes. 

Another study in 40 obese or overweight individuals found that those who received omega-3 fats containing 1020 mg of EPA and DHA combined for 12 weeks while following a weight loss diet saw an increased reduction in abdominal fat mass.

In a study of 44 men and women, the effects of fish oil supplementation versus safflower oil on body composition were analyzed after six weeks of either taking 4 grams of safflower oil or 4 grams of fish oil. The group that received fish oil significantly increased lean mass and decreased fat mass. They also saw a reduction in salivary cortisol following fish oil supplementation. 

While there was no significant difference in body mass or weight loss, what is important to note is that the fish oil group saw increased lean mass and decreased fat mass. Muscle weighs more than fat, so even though fish oil did not affect weight loss, fish oil did cause fat loss, which is huge!

When there is inflammation in the body, cortisol is produced to counter the effects of inflammation as cortisol is anti-inflammatory; thus, a reduction in cortisol could mean a reduction in inflammation due to taking fish oil. High cortisol levels can also counter the effects of insulin, thus causing increased insulin resistance. 

Fish oil for insulin resistance

A meta-analysis of 17 studies was reviewed to observe fish oil supplementation’s effects on insulin sensitivities. In the pooled analysis, omega-3 fish oil did not affect insulin sensitivity. But what was discovered in a subgroup of people with at least one symptom of metabolic disorders is that fish oil supplementation increased insulin sensitivity. 

These results show that fish oil benefits obese people with insulin resistance and additional symptoms of metabolic disorders such as high triglyceride levels and high blood pressure. While healthy people may not have the same increase in insulin sensitivity, fish oil still may have the potential benefit of preventing insulin resistance from developing, as was shown in the mice studies. 

Fish oil for weight loss is dependent on the APOE genotype

A fascinating study in mice found that the effects of fish oil on weight loss and insulin sensitivity were dependent on the APOE genotype. APOE3 and APOE 4 mice were fed a high-fat diet or a high-fat diet supplemented with 3% omega-3 fats from fish oil for 8 weeks. 

The high-fat diet induced more weight gain, higher blood lipids, higher insulin levels, and impaired glucose tolerance in APOE3 mice compared to APOE4 mice. Supplementing APOE3 mice but not APOE4 mice with fish oil resulted in decreased body weight, blood lipids, insulin levels, and improved glucose tolerance. 

This study in mice shows that the effect of dietary fish oil on weight loss and insulin sensitivity is dependent on the APOE genotype. Just another reason why I love genetic testing and personalized nutrition. 

Foods vs fish oil for weight loss

The omega-three fats found in fish oil are converted into anti-inflammatory prostaglandins that help to modulate and reduce inflammation in the body. Reducing inflammation is crucial for losing weight and reversing insulin resistance.

The omega-three fats also need to be in balance with the omega-six fats, which can be converted into pro-inflammatory arachidonic acid as well.

These days, omega-six fats are found everywhere, such as in fried foods, baked goods, and store-bought salad dressings. As a result, many people’s diet is very high in omega-six fats and low in essential omega-three fats.

Consumption of saturated fats and omega-six fats is prevalent in so many foods, and the ratio of omega-six to omega-three fats has been thrown way out of balance.

The best omega-3 supplements to help reduce inflammation and weight loss are the anti-inflammatory omega-three fats found in fish oil which contains eicosapentaenoic acid and docosahexaenoic acid, also known as EPA and DHA.

The foods highest in EPA and DHA include wild-caught fish such as sardines, salmon, mackerel, and herring.

The essential alpha-linolenic acid (Omega 3 fats) are healthy fats found in plant foods such as flax seeds, chia seeds, walnuts, and pecans and are converted into EPA and DHA in the body. Other vegetables high in omega-three fats include spirulina, dried seaweed, red peppers, leeks, and spinach.

The only problem with plant-based omega three fats for reducing inflammation and weight loss is that only some people convert plant-based ALA into EPA and DHA very well.

Genetic testing can determine if someone has SNPs in the enzymes involved with these conversions and whether you are likely to be a good converter or poor converter of ALA into EPA and DHA.

In the past, I have struggled with insulin resistance, inflammation, and weight gain. Thus it was interesting to note on my strategene report that I was a poor converter of ALA into EPA and DHA while also having SNP’s that upregulated the production of inflammatory arachidonic acid. 

While not all studies correlate a direct relationship between fish oil and weight loss in humans, there is strong evidence that there are many beneficial effects of fish oil, including abdominal fat loss, decreased weight circumference, and improved insulin sensitivity among individuals with symptoms of metabolic syndrome. 

Even if fish oil does not directly aid in weight loss for all people, fish oil may prevent further weight gain and can be helpful as a supplement to help maintain weight loss. 

Omega 3 fatty acids found in fish oil may help to improve body composition by modulating fat metabolism and reducing inflammation in fat tissues. Fish oil can also help promote abdominal fat loss and lean body mass. 

The omega-3 polyunsaturated fatty acids are vital in managing and reducing inflammation. Excess inflammation causes many health problems and makes losing weight more challenging. Plus, inflammation is a risk factor for developing diabetes. 

Fish Oil Supplements

It is best to use a fish oil supplement to ensure you are getting the omega-3 benefits for weight loss, insulin resistance, and fat loss. Unfortunately, not all fish oil supplements on the market are equal. 

Optimal Fish Oil by Seeking Health is certified for impeccable purity, cleanliness, and stability standards. Unique filtration methods are utilized to ensure purity and the removal of heavy metals, PCBs, and other contaminants. Their fish oil has over 70 5-star reviews for good reason. One soft gel provides a total of 964 mg of omega-3 fatty acids. 

You can also increase your fish consumption of wild-caught fish high in EPA and DHA.

Wild-caught fish are some of the best foods that help reduce inflammation by providing the body with anti-inflammatory fats. Omega-3 fats are an essential component of a healthy diet, and most people need more omega-3 fats in their diet.

Combining a low-saturated fat diet with a diet high in omega-three fats found in fish oil for weight loss is one of the best ways to lose weight. Eating an anti-inflammatory diet full of fruits and vegetables that are low in calories yet high in antioxidants and nutrients will reduce inflammation, reverse insulin resistance, and promote weight loss.