4 Evidence Based Reasons Why Whey Protein Is Good For Weight Loss

Among the myriad of weight loss solutions and quick fixes available, it is difficult to find that one thing which you could rely on.

We are doing our little bit by reviewing every such solution and informing you about the scientific reasons behind them but definitely, we can't predict which will work for you.

Whey protein is very popular among bodybuilders and athletes and you must be wondering how does this help in weight loss if it increases mass.

But that's what we want right!? Decreased fat mass with increased muscle mass...though the aim isn’t to be a bodybuilder.

What is Whey Protein?

Dairy protein is made up of 2 major classes: casein (80%) and whey (20%). Whey is the water like substance that remains after cheese production.

Casein is a group of proteins that precipitate from raw milk in presence of acid.

They coagulate to form clumps and are maintained as a colloidal suspension in the milk.

Whey proteins, on the other hand, remain soluble and can be seen as water like liquid which is further processed.

Based on the processing whey protein is classified as :

  • Whey protein powder: This is the commonly available form which is used in food products and also as sports and nutritional supplements.
  • Whey concentrate: It is whey protein devoid of water, lactose, ash and some minerals. It is rich in biologically active components and is used by athletes.
  • Whey protein isolate: It is the purest source of whey protein containing about 90% of proteins. It involves the removal of fat and lactose and is good for lactose intolerant individuals.

Why Whey Protein Is Good For Weight Loss

How does whey protein help in weight loss?

Whey is a dairy protein and protein causes weight loss by raising metabolism and reducing appetite.  It is a complete protein rich in vitamins and minerals.

It contains a large number of essential and branched chain amino acids (BCAAs) which are effective at promoting muscle development.

Additionally, these BCAAs promote satiety by regulating the secretion of appetite-controlling hormones.

Apart from that whey contains bioactive components like glycomacropeptide, alpha-lactalbumin, lactoferrin, and lactoperoxidase.

Each of these contributes to satiety promotion.

Alpha-lactalbumin has a high proportion of amino acids like leucine, lysine and trypthophan. Tryptophan is required information of brain chemical-serotonin which if modulated can reduce appetite.

Leucine and lysine are ketogenic amino acids and decrease appetite under ketogenic conditions. (Ketogenic means a metabolism where the body burns fats as fuel)

Whey Protein for Weight Loss

Whey protein is highly researched upon. Let's go over how this research is relevant to weight loss.

1. It promotes fat loss

In a clinical trial, healthy but obese individuals were given either whey protein or soy protein or carbohydrate for 23 weeks and effect on body weight and composition was studied. Body weight and fat mass did not differ in whey and soy protein groups.

However, in comparison to the carbohydrate group the whey protein group lost 2.3 kg body weight and 1.8 kg fat mass.

Researchers concluded that whey protein instead of soy protein affects body composition.

Another study exclusively in obese males also reported similar results.

That does not discredit soy protein, it is a healthy vegan source of protein. Whey is richer in leucine (an amino acid) than soy which is why it is absorbed faster and aids in quicker muscle development.

An animal study demonstrated that a high protein diet made up of whey protein concentrate is more effective in reducing body weight and increasing insulin sensitivity than a high protein diet made of red meat.

A commercial whey fraction was tested for its efficacy in altering body composition. Within 12 weeks the group taking whey protein lost 6.1% of their body fat.

What does this mean?
Whey protein stimulates fat loss and is proven to be better than other protein sources like casein, soy and red meat.

2. It controls appetite

Whey protein is found to be very effective in controlling appetite. Four components of whey protein which possesses satiating properties are :

  • Bioactive peptides
  • Whey protein fractions
  • Amino acids released from whey after digestion
  • Combination of above-mentioned components with other milk constituents

Studies show that whey protein controls appetite by modulating hormones like cholecystokinin, glucagon-like peptide 1, ghrelin etc.   These are stomach related hormones that regulate appetite.

Researchers at Maastricht University, Netherlands have found that GMP- enriched whey is more satiating than whey alone.

Out of the two milk proteins, whey is found to be more satiating than casein.

In fact, it has been proven that whey controls appetite better than casein and soy protein.

A review study suggests that whey is satiating in the short term whereas casein is satiating in long term.

A study was designed to compare the satiating effect of whey and casein in obese individuals.

When short term scores were taken into account whey was found to be more satiating than casein but over 12 weeks casein exerted a stronger appetite control.

What does this mean?
Whey controls appetite well in short term thereby reducing calorie intake.

3. It helps in the development of muscle mass

A study was conducted to examine whether whey protein promotes muscle mass development during resistance training.

Individuals were given soy or whey or carbohydrate supplements and trained for 9 months.

A slight decrease in fat mass was observed in all groups. Increase in muscle mass was as follows:

  • Whey- 3.3 kg approx
  • Carb- 2.3 kg approx
  • Soy-1.8 kg approx

Another study by researchers at Purdue University demonstrated that whey supplementation for 9 months resulted in 1.9% increase in lean mass and decreased fat mass by 2.6% in obese individuals.

CLA image 2Miller et al conducted a review study on the role of whey protein in resistance training and the conclusion was as follows:

‘The current body of literature supports the use of WP, either as a supplement combined with resistance exercise or as part of a weight loss or weight maintenance diet, to improve body composition parameters.’

A supplement rich in whey protein, leucine, and vitamin D is found to preserve muscle mass in older adults during intentional weight loss.

Weight loss around of around 3.4 kg and fat loss of 3.2 kg was observed.

Combination of whey protein supplementation and resistance training reduces visceral fat (harmful fat surrounding organs).

However, one study opposes these results.

A 12 week study in elderly people where whey protein supplementation was provided with resistance training reported no change in body composition.

What does this mean?
Whey protein preserves muscle mass during weight loss by calorie restriction and brings about better results in combination with resistance training.

4. It improves metabolic parameters

Whey protein has found to be therapeutic in case of abnormal metabolic parameters.

When digested, amino acids present in whey initiate release of several digestive hormones and enzymes which regulate the activity of insulin release.

Bioactive fraction of whey like dipeptidyl peptidase-4, prevent incretin (group of hormones that decrease blood sugar levels) from being destroyed and such action can help treat diabetes.

Whey protein improves blood glucose tolerance in individuals suffering from diabetes, reduces blood pressure and inflammation.

Whey protein supplementation improves blood lipid parameters like cholesterol in non-diabetic obese individuals.

What does this mean?
In addition to causing weight loss, whey protein improves metabolic parameters which can serve to be therapeutic in case of diabetes and metabolic syndrome.


Whey protein by itself does not have a palatable taste which is why flavored forms are available. However, watch out for the sugar content of such versions.

In most studies quoted above the range of whey protein administered is somewhere between 45-60g a day.

However, you can start with 20 g a day and gradually build up the dose each week.

It is better to follow dosage instructions as mentioned on the label of your whey protein supplement.


Whey protein, in general, does not cause side effects. If taken in excess, you can face gastrointestinal discomfort like nausea, bloating, diarrhea etc.

Some people are allergic to whey and those who are lactose intolerant should preferably go for a different protein source.

If suffering from kidney or liver problems or perhaps any other health problem, it is advisable to consult a health practitioner before taking any dietary supplement.


Whey protein is a great source of complete protein that aids in controlling appetite, reducing fat mass and increasing muscle mass.

Overall, based on the research that has been done, we would say that whey protein is definitely a reliable weight loss solution for the long term.

Also, it is a great option for those who want to raise their regular protein intake or would prefer a complete protein source apart from meat.

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