Know Whether Fish Oil Really Helps You Lose Weight

know whether fish oil really helps you lose weight

Fish oil is quite a common supplement available in the market. It is richly abundant in omega-3 fatty acids that offer a host of health benefits. With its use, health of the brain and heart improves.

Researchers say that omega-3 fish oil supplements help you lose weight easily. But, the jury is still out on this subject. This article studies the present scenario, whether omega-3 fish oil can help you lose weight.Fish oil omega-3

What are Omega-3 Fatty Acids?

These are essential for human health. The two main types of omega-3 fats are:

  • Essential Omega-3 Fatty Acids: Alpha Linolenic Acid (ALA) is an essential fatty acid. It is present in different types of plant-based foods. Oils of hemp seed, walnuts and chia seeds are important and rich sources of omega-3 fatty acids.
  • Long-Chain Omega-3 Fatty Acids: Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important long-chain omega-3 fatty acids. They are generally present in fish oil and other seafoods.

what are omega 3 fatty acids


ALA cannot be produced by the body, so you must get it external sources through diet. EPA and DHA aren’t considered necessary because the body utilizes ALA to produce them. Hence, ALA is essential. There is only little conversion in humans. Body converts only 2-10% of ALA in EPA and DHA.

So, health experts suggest that you should take around 200-300mg of EPA and DHA in a day. You can take a supplement for this.

DHA and EPA are important in the development and functioning of the eyes and brain. Studies claim that maintaining appropriate amounts of EPA and DHA in the body can prevent depression, inflammation, ADHD and breast cancer.

Fish Oil Reduces Hunger and Curbs Appetite

These help lose weight by lowering the appetite and hunger. When on a weight loss diet, you may feel hunger pangs, so fish oil is helpful in such situations.

In a study, healthy people on a weight-loss diet consumed less than 0.3 g of fish oil and some consumed more than 1.3g. The second group reported feeling fuller after two hours of the meal. But, these effects are not applicable to all.[1]

For example, in another study, adults not on a weight loss diet were either given 5 g of fish oil or placebo every day. The group, who consumed fish oil was reported feeling less full after having a breakfast and had more desire of eating.[2]

Similarly, in other studies, a group of patients with cancer or renal disease reported increase in appetite when given fish oil as against the second group, who were given a placebo. [3,4,5]

Also, a study noted that fish oil boosted the level of hormone that made a person feel full in obese people, but decreased the hormone levels in non-obese people.[6] So broadly, effects depend on the diet and health status.

Fish Oil Increases Metabolism

Fish oil can help you lose weight by enhancing your metabolism. Metabolism is measured by metabolic rate, which calculates the number of calories burnt in a day. If the metabolic rate is high, you burn more calories, making it easier for you to lose weight and also keep it off.

According to a study, when some healthy individuals consumed 6 gm of fish oil every day for 12 weeks, the metabolic rate went up by around 4%.[7] Another study showed that when healthy old women consumed 3 gm of fish oil every day for 12 weeks, the metabolic rate rose by 14%, which is the same as burning additional 180 calories every day.[8] One more study indicated that when healthy adults consumed 3 gm of fish oil each day for a duration of 12 weeks, their metabolic rate increased by about 5%.[9]

Studies that claimed increase in metabolic rate also reported increase in muscle mass. Calories are more burnt by muscles than fat. However, more studies are needed to know the true effects of fish oil on the rates of metabolism.

fish oil increases metabolism


Fish Oil May Amplify the Effects of Exercise

The metabolic effects of fish oil are not only associated with burning calories each day. Research says that fish oil can increase the amount of fat that gets burnt during exercise. This is because fish oil helps in utilizing fat in place of carbohydrates as a source of energy during exercise.[10]

A study revealed that women, who consumed 3 gm of fish oil each day for a period of 12 weeks burnt 20-27% more fat and 10% more calories when they did some sort of exercise.[11] For this reason, it is said that having fish oil along with exercise is more beneficial than just exercising. But more research must be conducted to arrive at conclusions of any sort.

Fish Oil Helps in Losing Fat

It is quite possible that fish oil omega-3s may not be beneficial in losing weight. But they certainly help build muscles and loose fat. So, people, who are on a weight loss journey, should assess their body fat percentage rather than simply depending on the scale.

During another study, a few healthy adults replaced 6 gm of fat with 6 gm of fish oil every day for about three weeks. It was found that they did not lose any weight after the fish oil diet, but they lost body fat.[12]

Another study found that the participants, who took 3 gm of fish oil every day lost 0.6 kg of fat as compared to those, who were given a placebo. But, the total body weight remained the same.[13]

A review of 21 studies said that fish oil does not lead to reduction in body weight more than a placebo. But it has been found that fish oil reduces the waist to hip ratio and circumference of the waist.[14]

So, fish oil may not itself cause you to lose weight but the thing is that it will make it simpler to lose weight. Consumption of fish oil is deemed safe, but it should not be more than 3,000 mg per day. The European Food Safety Authority (EFSA) recommends daily intake of 5000 mg to be safe.

Omega-3 also sometimes thins the blood. This may cause bleeding in some people. If you are already taking medicines for blood thinning, speak to your doctor or healthcare provider about adding fish oil supplements to your medicine cabinet.

Also, know about the fish oil supplements that you are taking. Some of the supplements may be having vitamin A, which are poisonous when consumed in excess amounts, particularly in younger children and expecting mothers. Always make it a habit to pick a supplement tested by a third party.


Fish oil having omega-3 has lots of health benefits. A prominent benefit is that it helps in weight loss. But, these effects may not be applicable to one and all. It maximally benefits when it is combined with regular exercise and proper diet.