5 Ways Omega 3 Fatty Acids Benefit In Obesity

Dietary supplements are usually a concentrated version of certain bioactives found in natural foods.

You generally don’t need to opt for them if you already consume those foods in good proportion.

Now that is not always the case.

Like there is one supplement which is a must for me- omega 3 fatty acids.

We consume very little seafood and it is always not possible to include omega 3 rich foods in the diet which is why I opt for this supplement.

What are Omega 3 Fatty Acids?

Omega 3 fatty acids are a group of healthy fats.

They are polyunsaturated fats- they have multiple double bonds and are not saturated with hydrogen.

They are essential fatty acids- they cannot be produced in the body but are responsible for their healthy functioning.

They get the name omega due to the structure of the molecule (first double bond at 3 carbon atoms away from omega).

The three main omega 3 fatty acids are: alpha linoleic acid (AHA), docosahexaenoic acid (DHA) and eicosapentaenoic acid(EPA).

The parent fatty acid for omega 3s is alpha linoleic acid which is converted to EPA and in turn converted to DHA.

DHA is an important component of the cell membranes of the brain and retina and hence is required for healthy neural and visual functioning.

That is the reason why we find these supplements good for health.

Omega 6 is the other group of essential fatty acids and it is the dietary omega 6 and omega 3 ratio that is being hampered.

The modern diet has too much of omega 6 and little of omega 3 and this can increase the risk of developing diseases like heart problems, type 2 diabetes.

That is why the focus is shifting on increasing omega 3 intakes either through diet or as supplements.

Omega 3 Fatty Acids for Weight Loss

Despite the old notion ‘Fat makes you fat’, omega 3 fatty acids are the healthy fats and they are essential for optimum body functioning.

A number of studies have been conducted which reveal how omega 3 fatty acids can help in treating obesity.

Few of the mechanisms involved are:

  • Promoting expression of genes that suppress fat accumulation
  • Increase in fat regulating hormones like adiponectin and leptin
  • Appetite suppressing effects
  • Promoting burning of cellular fat
  • Reduction in size and number of fat cells
  • Prevention of accumulation of body fat and development of fat cells
  • Modulation of gene targets like PPAR which regulate cellular and fat metabolism

The effect of omega 3 fatty acids on obesity and related metabolic disorders has been greatly researched upon.

1. They prevent weight gain

A number of animal studies show that omega 3 fatty acid supplementation prevents accumulation of body fat in response to high-fat diet.

In one animal study genetically lean and obese mice were given a diet supplemented with either evening primrose oil or cod liver oil for 16 weeks.

It was observed that the genetically obese mice who consumed cod liver oil had lower body weight than the ones who consumed evening primrose oil.

Other studies show that omega 3 fatty acids attenuate the development of fat depots and visceral fat (harmful fat that surrounds organs).

These findings point out that omega 3 fatty acid supplements can reduce abdominal and subcutaneous fat accumulation.

A study was designed to investigate whether omega 3 fatty acid supplements alone could cause weight loss.

Initially, participants were given 6g of fish oil supplements per day for 4 weeks.

This was then continued for another 4 weeks where the participants were also given a very low energy diet.

It was observed that those who took fish oil supplements prior to the intervention lost significantly more body weight and fat than those receiving placebo.

What does this mean?
Animal studies show that omega 3 fatty acid supplementation prevents diet induced obesity.

2. They promote weight loss outcomes of diet and exercise

Obese individuals have lower levels of omega 3 fatty acids in comparison to healthy individuals.

Similar observation has been made in children.

Observational studies show that high fatty fish intake is associated with lower body weight.   Dietary fish oil reduces fat mass by stimulating the breakdown of fats.

Weight loss outcomes of a very low calorie diet are enhanced with omega 3 fatty acid consumption and DHA is found to be an active component behind this.

Researchers reported a 1.5kg greater weight loss in a group taking fish oil along with other weight loss technique compared to those taking placebo.

A combination of ketogenic (very low carbs) Mediterranean diet and omega 3 fatty acids is beneficial for cardiac diseases and inflammation. This study  also reported a 5.8 kg decrease in body fat in the omega 3 group but over the period of 12 months.

Fish oil supplements in combination with aerobic exercise improve weight loss outcomes and metabolic health.

Weight loss in these studies were mostly fat loss ranging from 1-3%.

Krebs et al conducted a study  wherein the effect of the addition of fish oil to weight loss program was observed. Weight loss was significant in fish oil group (10.8%) and this lead to improvement in metabolic parameters.

Omega 3 fatty acid supplementation is found to be helpful for children who are at the risk of developing obesity.

Researchers at the University of South Adelaide have put together all the possible studies conducted on omega 3’s effect on body weight in their paper ‘Long-Chain Omega-3 Polyunsaturated Fatty Acids May Be Beneficial for Reducing Obesity—A Review’.

They comment that till date studies on this topic are of short duration and outcomes are modest which warrants the need for long term studies.

What does this mean?
Obese individuals have lower levels of omega 3 fatty acids compared to healthy individuals. A number of clinical trials show that omega 3 fatty acid supplements cause modest weight loss not only in adults but also in children. Few studies report that omega 3 supplements can boost the weight loss caused by diet or exercise alone.

3. They reduce stubborn belly fat

Belzung et al showed that fish oil supplementation reduces the size of fat cells in abdominal fat depots and prevents fat accumulation.

Dietary omega 3 fatty acids prevents increase in size and number of fat cells.

A study  in diabetic women supplemented with omega 3 fatty acids reported no change in body weight but a decrease in subcutaneous (under the skin) fat within 2 months.

Another study  conducted on diabetic population, investigated the effect of protein enriched low carb diet and omega 3 fatty acid supplementation on metabolic parameters.

One of the important outcomes of this study was that waist circumference decreased by approximately 4 cm serving as an indicator of improved metabolic health.

A review of clinical trials focussed on the anti-obesity effect of omega 3 fatty acids also revealed that these supplements cause a significant reduction in waist circumference.

What does this mean?
The weight loss caused by omega 3 fatty acids is preferentially fat loss especially in abdominal fat and also trunk area fat. It also aids in reducing postmenopausal weight gain.

4. They regulate fat and satiety related hormones

A number of hormones are involved in the regulation of fat deposition and energy intake. Adipokine is one such hormone.

Abnormal secretion of adipokine can cause increased fat depot, insulin resistance and inflammation.

Omega 3 fatty acid supplementation can positively regulate genes responsible for adipokine secretion.

This effect of omega 3 fatty acid is proven to be beneficial in polycystic ovarian syndrome.

Leptin is an appetite suppressing hormone. It also regulates body fat accumulation and a few obese individuals do suffer from leptin resistance- where the body cells refrain from responding to leptin’s effect.

Omega 3 fatty acids are found to help in normalizing leptin levels and this is of relevance to weight maintenance.

Long chain fatty acids suppress appetite by manipulating hormones involved in it. DHA stimulates the high release of cholecystokinin, an appetite modulating hormone.

A high dose of omega 3 fatty acids (1300mg) is found to increase post meal satiety.

What does this mean?
Omega 3 fatty acids regulate hormones involved in fat metabolism, thereby reducing fat accumulation and blood lipids.

omega3 for weight loss

5. It improves metabolic parameters

A clinical trial  was conducted wherein individuals suffering from metabolic syndrome were given fish oil capsules for 6 months.

At the end of the study, significant drop in body weight, cholesterol, blood pressure and inflammatory parameters was observed.

Omega 3 fatty acids reduce obesity induced inflammation.

3 month treatment with omega 3 fatty acids is found to reduce inflammation and improve vascular function (improved blood flow) in obese adolescents.

They also aid in improving insulin sensitivity and can be used as an add on therapy for insulin resistance.

Omega 3 fatty acids also regulate cholesterol and blood lipids in obese individuals.

A review study  notes that omega 3 fatty acids can improve features of obesity and metabolic syndrome like hypertension, insulin resistance and high lipid levels etc.

What does this mean?
Omega 3 fatty acids protect against cardiac, metabolic and brain diseases.

Some scientists have a different opinion about omega 3 fatty acids anti-obesity effect

A study  by the Australian institute compared the effect of monounsaturated oil and omega 3 fatty acids on body weight.

At the end of 12 weeks significant reduction in body weight was observed but the results were not different in either group.

They concluded that omega 3 polyunsaturated fatty acids have no effect on body weight but poor dietary compliance could have been responsible for the results.

The same researchers also showed that dietary supplementation of omega 3 PUFAs with low energy diet does not aid in weight loss.

However, a significant reduction in fat mass with fish oil consumption was noted by researchers.

Results of a study  suggest that omega 3 fatty acids are not as effective as an adjunct treatment for weight loss.

128 obese individuals were enrolled in the study and given either a placebo or omega 3 supplements (5:1 ratio of EPA to DHA) for 6 months.

Average weight loss was around 5% but no significant differences were seen in both groups.

A meta analysis study  was conducted where 21 studies were included. Based on calculation it was observed that fish oil supplementation had no significant effect on body weight or BMI.

But they commented that these supplements do cause a significant reduction in waist circumference.

What does this mean?
Few studies report that omega 3 supplementation is not effective in reducing body weight as the outcomes are almost similar to placebo group.
Weight loss outcomes with omega 3 fatty acids may be modest but if your weight gain is a consequence of metabolic disease then omega 3 is most likely to help you.

Therapeutic effects of omega 3 fatty acids

Omega 3 fatty acids are ‘essential’ fatty acids and therefore are likely to reap a number of health benefits and have therapeutic effects:

Natural sources of omega 3 fatty acids

You can also obtain omega 3 fatty acids from plant and sea foods.

Sources of Omega 3 fatty acids Content of EPA, DHA or ALA
Flax seed 2.2g/5 ml
Flax seed oil 8.5g/5 ml
Hemp oil 3.1g/5 ml
Canola oil 1.3g/5 ml
Soya bean oil 0.9g/5 ml
Dark green leafy vegetables Small amounts
Walnuts and pine nuts 0.7g/5ml
Krill oil and shellfish varies
Chinook salmon 1g/60g
Rainbow trout 1g/90-95g
Mackerel 1g/60-240g
Sardines 1g/60-85g
Herring 1g/30-60g

Krill oil, cod liver oil and fish oil are excellent sources. However you cant use them for cooking and they don’t have that palatable a taste which is why it is advisable to take fish oil or cod liver supplements.


FDA suggests that maximum dose of EPA and DHA should be 3g with 2g coming from a dietary supplement.

Health Canada suggests a dose of 1500mg for men and 1100mg for women (age 25-49 years).


Omega 3 fatty acids do not pose any side effects.  Mild gastrointestinal symptoms like bloating, indigestion may occur.

Omega 3 supplements can prolong bleeding time so people taking anticoagulants or non steroidal anti-inflammatory drugs should exercise caution while taking these supplements.

In case you are allergic to seafood you should avoid these supplements and opt for other sources of omega 3.

Consult a doctor before taking omega 3 supplements if you are suffering from any health condition.


Omega 3 fatty acids are essential for healthy functioning of the body. Their effect on weight loss is modest but they work well in combination with low calorie diet and exercise.

Omega 3 fatty acids can likely help if you suffer from metabolic disease and thus aid in weight loss. But you cant expect a miracle from this.

Nevertheless, we will advise yo tou take this supplement as it is a neuro and cardioprotective agent, essential for the body and difficult to acquire in necessary amounts from natural sources.

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