4 Benefits of Kelp for Weight Loss & Obesity

With obesity becoming an epidemic, novel ways have been discovered to combat it.

The most effective and healthy way to combat it includes healthy lifestyle changes which have become difficult for many us to adhere to or even begin to make.

Therefore, easier ways to overcome obesity are becoming increasingly popular such as Anti-Obesity Drugs.

Many of them pose potential health threats and the research on others isn’t complete.

Therefore, there is an increase in the reliance on natural food products that have the same effects as anti-obesity drugs without their health hazards.

The terms ‘Functional Foods’, ‘Nutraceuticals’ or ‘Superfoods’ have become quite popular.

These are nothing but naturally available foods that do not just provide basic nutrition but go beyond that and provide special health benefits, this may be due to the presence of special bioactive compounds or phytochemicals in them [1].

Having said that coming to the topic at hand- Kelp for Weight Loss.

What is Kelp?

The newest superfood on the block is Kelp. What is Kelp? Kelp is nothing but Brown Algae (more commonly called as Seaweed).

That, of course, is a broad generalized classification. Getting into the technicalities of it, not all brown algae that you find in the ocean is Kelp.

Brown algae belonging to genus Laminaria is called true kelp, and other genera such as Macrosystis and Nereocystis also include Giant and Bladder Kelps. Kombu, Arame, Wakame are various other kinds of kelp [2].

Kelp grows in groups- ‘kelp forests’ that are found under cool shallow waters along the rocky ocean shores of the Pacific coast.

They quite often might look like trees growing up to a height of 2-30 m from the ocean floor [3].

Kelp forests provide home, food and spawning beds for a number of fishes, invertebrates, and other marine animals.

Kelp may have become popular now as a superfood, but it has been used in the food industry for quite a while.

Alginates- these compounds are made from kelp and are often used to improve textures (giving them a smooth, thick texture) of foods such as ice-cream, chocolate milk, toothpaste and sometimes even in cosmetics [4].

However, its use as a food supplement is relatively new and not much substantial evidence is available to support the claim of it being a superfood.

Kelp contains crude proteins and has high contents of fiber, minerals, and vitamins in them [5].

They are richer in unsaturated fatty acids (PUFAs and MUFAs) as compared to saturated fatty acids and have as much as 70% fatty acids as PUFA.

They are rich in Iodine which makes it quite popular in the treatment of Thyroid related disorders [6].

There have been quite a few studies that suggest the use of kelp in the treatment of Obesity and other diseases associated with it such as Diabetes.

‘Kombu’ (Laminaria japonica) is brown algae that have been found to be helpful in the treatment of obesity by affecting the triglyceride absorption (antihyperglycemic effect).

The compound responsible for it is believed to be Alginic acid [7].

An animal model of obesity suggested a suppression in weight gain and reduced levels of cholesterol and triacylglycerols with the administration of seaweed or kelp in powdered form10.

One study suggested the positive effects of kelp in the treatment of obesity and its related disorders, in an animal model.

They showed an increase in energy expenditure, a better lipid profile among other cellular changes that contributed to the treatment of obesity in the obese rats11.

A significant change in the eating habits of human subjects was observed on supplementation with kelp.

They showed a reduction in food intake, however, no change in blood glucose and cholesterol was observed [8].

Kelp supplements have often been used as ‘fat burners.' Fat burners increase the breakdown of fat, reduce its absorption and increase its oxidation during exercise [9].

4 Benefits of Kelp for Obesity

The anti-obesity property of kelp can be attributed to the presence of the following bioactive components present in them- Alginates, Fucoxanthin, Fucoidans, and Phlorotannins.

They bring about weight loss in the following ways:

1. It Curbs Appetites

The dietary fibers present in kelp have a bulking property and cause a feeling of satiety.

Alginates that are a derivative of Alginic acid (a carbohydrate) constitute up to 40% of the dry weight of kelp give kelp a gelatinous texture, which causes it to bulk up in the stomach and cause a feeling of satiety11.

When alginates were used as an independent dietary supplement the subjects showed enhanced satiety and a resultant reduction in the food intake.

Their gelling and viscous properties have known to be similar to other dietary fiber such as Pectin11.

What does this Mean? The alginates present in kelp become viscous and gel-like in the stomach causing bulking which in turn causes a feeling of satiety. This subsequently makes the person consume lesser calories.

2. It Prevents Fat Accumulation

A sulfated polysaccharide, Fucoidan present in kelp has been found to inhibit adipogenesis (formation of adipocytes, fat cells), adipocyte differentiation and their accumulation [10].

It also increases the expression of Hormone Sensitive Lipase (HSL) that brings about lipolysis (the breakdown of fat) [11].

All these changes are a result of the interference of Fucoidan at the cellular levels bringing about suppression and expression of certain genes [12].

In an animal study when rats were fedfucoidan, they exhibited a decrease in weight gain, reduction in body fat along with improved blood lipid profiles11.

However, there is limited availability of human-based trials that are carried out to study the effects of fucoidan in obese individuals.

One study including 25 obese individuals suggested decreased diastolic blood pressure and better lipid profiles post-consumption of fucoidan11.

What does this Mean? Fucoidan present in them has a lipolytic effect and also inhibits fat accumulation by operating at a cellular level, suggesting its use in the treatment of obesity.

3. It Regulates Fat Metabolism

Most of the brown seaweeds contain a polyphenol called Phlorotannin. These phlorotannins are known to have anti-obesity effects.

They also are helpful in alleviating obesity-related disorders [13].

They bring about the said effect by preventing the absorption of fat due to the inhibition of Pancreatic enzyme lipase.

Not only Phlorotannin but Alginates and Fucoidan are also known to have an inhibitory effect on the activity of pancreatic lipase11.

They also caused the destruction (apoptosis) of preadipocytes, along with suppression of adipogenesis11.

What does this Mean? The destruction of fat cells and the suppression of formation of new fat cells due to the Phlorotannin present in brown seaweeds makes it an amazing alternative to anti-obesity

Drugs. Though the use and efficacy of phlorotannin being used as an anti-obesity agent still need more research using animal and human models.

4. They have an Anti-Inflammatory Effect and Reduce Obesity-induced Inflammation

Fucoxanthin is a carotenoid found to be associated with brown seaweed.

The consumption of fucoxanthin rich kelp by obese mice brought about a reduction in their weight gain, modulation of blood glucose and insulin levels [14].

It was also found that fucoxanthin also helps in overcoming the low-grade inflammation that is characterised by obesity and a reduction in the white adipose tissue mass [15].

It also enhances the beta-oxidation of fat and reduces lipogenesis [16].

It also has an anti-oxidant activity; Fucoxanthin has been found to regulate lipid metabolism to bring about fat loss [17],[18].

What does this Mean? The carotenoid fucoxanthin regulates the lipid metabolism to bring about a reduction in the weight of white adipose tissue along with the inhibition of lipogenesis. It also has anti-oxidant and anti-inflammatory properties.


There is no specific dose of kelp for hyperthyroidism.

Kelp has received GRAS status. Mean intake of kelp in Japan is 7g per person per day. [19]

According to the FDA the intake of kelp should be limited to a dose of 0.15- 0.25 mg of iodine. [20]

This should be around 1g of kelp but the iodine contents vary with every species.

It is best to consult a health practitioner before consuming kelp in any form if you have thyroid issues.

The book, Drug Abuse Treatment Using Biochemistry mentioned that Kelp is seaweed that can be consumed raw but is usually processed in the powdered and dried form so that it can be used as a flavoring agent in dishes and can be easily included in the diet.

It is rich in nutrients and is mostly available as a supplement in the market. [21]

Therefore, whatever form you eat kelp in tablets or natural form make sure to check the label to check whether the iodine content is with the daily recommendation.


Kelp usually comes in powdered or capsule form; however, the consumption of kelp should be done under the guidance of a Physician.

Since it is rich in iodine case of both hyperthyroidism and hypothyroidism, have been linked with excessive consumption of kelp.

Therefore, people already having thyroid-related problems should avoid their intake.

Since kelp is found in oceans the chances of it being contaminated with harmful metals is high.

These harmful metals include Aluminium, Cadmium, Lead among others. Pregnant and breastfeeding women aren’t advised against the use of kelp supplements1.


Kelp not only has properties that help in weight loss but also has other beneficial properties such as anti-inflammatory, anti-oxidant, anti-cancerous property.

It has also been implicated in the maintenance of blood glucose and a healthy blood lipid profile.

The precautions with its consumption should be kept in mind. It is indeed a superfood but not magic food that helps you lose weight. There is no shortcut to healthy living.

For a healthier present and future, it’s important that all these measures be accompanied with healthy life choices and lifestyle changes.

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