Does Fish Oil Help You Lose Weight 2023? Impressive Benefits to Know


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Medically reviewed by Kathy Shattler, MS, RDN

does fish oil help you lose weight

Obesity and weight gain have fast become a global problem. With this, health authorities and nutrition experts are doing their part to advise the global population on possible solutions. One such solution is omega-3 fish oil, which is known to effectively help with weight loss.

Current recommendations for counteracting obesity and improving weight loss now advocate for healthy diets, the consumption of fish oil supplements, the inclusion of fruits and vegetables, the avoidance of processed foods, and participation in regular physical activity.

Weight loss helps you achieve many health benefits, including a reduction in abdominal fat, a reduction in blood pressure, and a reduced risk for heart disease overall. Pregnant women are advised to increase their consumption of omega-3 fatty acids to foster the proper development of the fetus’s neurological system. This is beneficial information for those pregnant women who must limit their weight gain for health reasons.

Omega-3 fatty acids must be obtained through the diet. They are essential fatty acids and the only way the body can make them is out of a substance called alpha-lipoic acid (ALA). The fish oil group contains preformed omega-3 fatty acids, so no conversion is necessary.

Does Fish Oil Help You Lose Weight?

In short, yes. As a solution to weight loss, fish oil[1] is one of U.S. adults and children’s most commonly used nutrients. Data from the 2012 National Health Interview Survey indicate that 7.8% of U.S. adults and 1.1% of U.S. children use supplements containing fish oil, omega-3s, and DHA (docosahexaenoic acid) or EPA  (eicosapentaenoic acid).

Supporting this is The Centers For Disease Control And Prevention[2], which states that the most widely used supplement is fish oil, with nearly 8% of adults and 1% of children taking these supplements. Another popular oil is olive oil, which contains both omega-3 and omega-6 oils and a monounsaturated fatty acid.

It’s no wonder fish oil has gained such popularity in recent times with its treatment role in medical conditions, the alleviating of physical symptoms, its promotion of physical health, and its use as a nutritional supplement to help with weight loss.

Benefits Of Fish Oil For Weight Loss

The true power of fish oil is in its long-chain polyunsaturated fatty acids EPA  and DHA, also called omega-3s. The human body cannot produce these compounds, so dietary inclusion is essential if weight loss and cardiovascular health are desired.

Greater Triglyceride Reduction 

When it comes to fish oil, supplements, and natural sources of omega-3, fish oil is associated with a bodyweight/fat reduction[3]. A weight-loss diet including oily fish results in greater triacylglycerol (TG) reduction. Individuals receiving a cod diet, salmon diet, or fish oil

experienced a greater reduction in TG concentration. Triglycerides are the main constituent of body fat. To reduce percent body fat, you want to reduce your stored triglycerides.

Improved Waist-Hip Ratio 

According to online research[4], fish oil and associated supplements from the fish oil group are also known to assist in improving the waist-hip ratio (WHR). This is the circumference of the waist to that of the hips and is one of several measurements doctors use to see if excess weight is putting an individual’s health at risk. 

Improved Resting Metabolic Rate 

Along with reduced WHR, fish oil helps in improving Resting Metabolic Rate (RMR), which helps in weight reduction. A research article[5] on the effects of supplemental fish oil on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults showed positive results. There was a significant increase in fat-free mass following treatment with supplemental fish oil, a significant reduction in fat mass, and a tendency for a decrease in body fat percentage.

Decreased Appetite

In the research article, there was also a tendency for salivary cortisol to decrease, and there was a significant correlation between change in cortisol and change in fat-free mass and fat mass. All this adds to significant weight loss. Cortisol is bad for weight loss because it increases your cravings for sweet and salty foods, thus leading to potential overindulgence[6] in processed, high-calorie snacks. These snacks are not just bad for your weight; they have few health benefits and may increase your blood pressure.

Improved Metabolism

Furthermore, fish oils have positively affected general metabolism in all age groups. With a higher metabolism, higher amounts of weight loss are experienced.

Weight Loss For Women And Youth

A recent online study[7] revealed that when healthy older women took three grams of fish oil per day for 12 weeks, their metabolic rates increased by around 14%, which is the equivalent of burning an extra 187 calories per day. A good rule of thumb is, that for every 100 calories per day that you save, you lose ten pounds per year.

Furthermore, another online study[8] reported that when healthy young adults took six grams of fish oil per day for 12 weeks, their metabolic rates increased by around 3.8%. This contributed to their weight loss and the burning of their fat storage.

Improved Fuel For Exercise

Apart from metabolism, weight loss also occurs due to exercise. With this, it is important to note that taking fish oil without exercise does not have much impact on an individual’s weight, so it’s important to consume fish oil along with exercise. 

Reduced Body Fat And Improved Body Composition

Fortunately, fish oils, fish consumption, and healthy fats are believed to switch carbohydrates to fat as a source of fuel during exercise, giving the individual more energy to perform long periods of exercise. With heightened fuel during exercise, individuals are able to exercise for longer, which positively affects weight loss. It is also known that fish oil supplements in combination with exercise have been shown to reduce body fat more effectively than exercise alone.

Improved Immune System

When it comes to the optimal immune system[9] functioning in support of weight loss, omega-3 can significantly reduce immune system functioning because it lowers the body’s inflammatory responses. With regards to muscle functioning – an important component in weight loss, fish oils promote muscle functioning. This helps to burn fat faster into muscle. 

A recent literature review revealed that omega-3s and healthy fats might also reduce the risk of cardiovascular disease, metabolic syndrome, and diabetes, which play a negative role in weight loss. Omega-3s, too, may provide an additional benefit by preventing weight regain following a calorie-restricted diet.

Improved Muscle Growth

Along with improved immune systems, fish oil and fatty acids stimulate protein synthesis, which helps build muscle mass and slow down muscle protein breakdown. The stimulation of the mTOR signaling pathway boosts the control system for muscle protein anabolism and muscle cell growth.  All in all, more muscle means less fat and a more significant weight loss journey.

Curbing Hunger

Online sources[10] report that fish oil capsules and fatty acids help to curb hunger and reduce bouts of overeating. Overeating at irregular times of the day causes severe weight gain, and with this, fish oil supplements can now reduce hunger and regulate an individual’s appetite. This is possible through the production of the leptin hormone, which is naturally produced by the body’s fat cells. The leptin hormone suppresses hunger and decreases hunger-promoting neurons’ activity.

Boosted Insulin Sensitivity

Fish consumption contains fatty acids that reduce insulin resistance which improves the metabolism of fats, proteins, carbohydrates, and other nutrients. Improved insulin sensitivity helps the body avoid the storing of excess amounts of glucose, which then avoids storing fat in the body cells.  All this has a possible effect on weight loss and overall body health.

Reduced Stress Hormones And Inflammation

Lastly, when it comes to being able to lose weight and the assistance of this, fish oil contributes to lowered stress hormones and inflammation. This, along with brain health, helps to keep the body at optimal weight.

Using Supplements For Losing Weight

While many fish oil supplements are readily available and adding them to an individual’s diet is relatively safe, the exact amount of fish oil per individual is yet to be clarified, with different authorities recommending doses anywhere from 300 mg to 3,000 mg/ day. Others like the U.S. Food and Drug Administration (FDA) believe that the intake of omega-3s is considered safe if the daily dose does not exceed 3,000 mg per day. However, the European Food Safety Authority[11] (EFSA), the European equivalent of the FDA, considers daily intakes of up to 5,000 mg to be safe. 

Other health and nutrition authorities like the Dietary Guidelines for Americans[12] recommend consuming two servings of fatty fish per week for optimal health, skin health, and brain health. Be careful of cod liver oil which contains high levels of fat-soluble vitamins A and D. Vitamin A may be toxic to your liver if consumed regularly in the form of cod liver oil. Healthy fats are still recommended as fatty acids aid in body functioning.


For individuals who take blood thinners or for those who are pregnant, it is recommended to check with a healthcare professional before adding fish oil content to the diet. This applies to children as well. Those with fish allergies seeking to lessen body weight are advised to avoid fish oil altogether. Individuals with pre-existing health conditions, and those taking weight loss medications and supplements, are advised to speak to their physician first before opting for fish oil.

When Should I Take Fish Oil For Weight Loss?

When it comes to the timing of fish oil consumption, it is advised to take fish oil over the long term and with food (mainly a good source of fat) as food helps in the absorption of the fish oil. Taking fish oil with food helps to reduce certain side effects, including acid reflux, diarrhea, belching, and nausea.

For those more serious about weight loss, consuming fish oil 30 minutes before or after a meal is advised. With this, as stated, exercise must be done. After all, consuming fatty acids along with a workout routine will boost fat-burning effects.

While some health experts believe that taking the fish oil at night is better than in the morning, it’s rather about finding a time that works best for the individual and consistently regulating this time for optimal effectiveness. All in all, establishing a routine and being consistent in taking fish oil supplements will maximize its potential health benefits.

Overall, if an individual is looking for a safe and effective approach to weight loss, a comprehensive program that includes a healthy diet, which includes fish oil, fatty acids, and healthy lifestyle counseling, offers the opportunity for long-term weight loss success. With in-depth nutritional coaching beyond calorie counting, it can be easier to make positive dietary choices that facilitate significant change and integrate fish oil into an individual’s eating plan. 

Final Thoughts: Can Fish Oil Reduce Body Fat?  

So, can omega 3 fish oil capsules help you burn those extra pounds? The answer is yes, especially when consuming fish oil daily! While weight loss results may vary from individual to individual, some individuals may experience amazing results, and others may, but not to such an extent. To get the maximum benefits, become a healthy adult, and lose fat, fish oil should be combined with regular exercise, necessary dietary changes, a healthy diet, and the elimination of processed foods, fatty foods, salty foods, refined foods, and sugary foods.

+ 12 sources

Health Canal avoids using tertiary references. We have strict sourcing guidelines and rely on peer-reviewed studies, academic researches from medical associations and institutions. To ensure the accuracy of articles in Health Canal, you can read more about the editorial process here

  1. (2015). Office of Dietary Supplements – Omega-3 Fatty Acids. [online] Available at:
  2. Clarke, T.C., Lindsey H I Black and Stussman, B.J. (2015). Trends in the Use of Complementary Health Approaches Among Adults: United States, 2002–2012. [online] Available at:
  3. Du, S., Jin, J., Fang, W. and Su, Q. (2015). Does Fish Oil Have an Anti-Obesity Effect in Overweight/Obese Adults? A Meta-Analysis of Randomized Controlled Trials. PLOS ONE, [online] 10(11), p.e0142652. Available at:
  4. Du, S., Jin, J., Fang, W. and Su, Q. (2015). Does Fish Oil Have an Anti-Obesity Effect in Overweight/Obese Adults? A Meta-Analysis of Randomized Controlled Trials. PLOS ONE, [online] 10(11), p.e0142652. Available at:
  5. Noreen, E.E., Sass, M.J., Crowe, M.L., Pabon, V.A., Brandauer, J. and Averill, L.K. (2010). Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults. Journal of the International Society of Sports Nutrition, [online] 7(1). Available at:
  6. Hewagalamulage, S.D., Lee, T.K., Clarke, I.J. and Henry, B.A. (2016). Stress, cortisol, and obesity: a role for cortisol responsiveness in identifying individuals prone to obesity. Domestic Animal Endocrinology, [online] 56, pp.S112–S120. Available at:
  7. Logan, S.L. and Spriet, L.L. (2015). Omega-3 Fatty Acid Supplementation for 12 Weeks Increases Resting and Exercise Metabolic Rate in Healthy Community-Dwelling Older Females. PLOS ONE, [online] 10(12), p.e0144828. Available at:
  8. Couet, C., Delarue, J., Ritz, P., Antoine, J-M. and Lamisse, F. (1997). Effect of dietary fish oil on body fat mass and basal fat oxidation in healthy adults. International Journal of Obesity, [online] 21(8), pp.637–643. Available at: [Accessed 10 Feb. 2022].
  9. News. (2017). Tracing the relationship between metabolism and immune response. [online] Available at:
  10. Vitagene. (2018). 3 Impressive Fish Oil for Weight Loss Benefits | Vitagene. [online] Available at:’s%20advised%20to%20take%20fish,the%20supplement%20with%20your%20food.&text=Don’t%20forget%20to%20exercise,can%20boost%20fat%2Dburning%20effects.
  11. European Food Safety Authority. (2012). Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). [online] Available at:
  12. Health Gov. (2015). Dietary Guidelines For Americans 2015-2022. [online] Available at:‌

Medically reviewed by:

Kathy Shattler

Stacey Rowan Woensdregt has more than 15 years of experience in print media, online media, copywriting, and digital marketing. She has written for many bespoke magazines and media houses and has worked within top digital marketing agencies around the world. Her niche markets include architecture, property, health and wellness, holistic medicine, art and lifestyle, and business.

Medically reviewed by:

Kathy Shattler

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