Supplements

Protein Shakes For Weight Loss

Protein shakes are used for many different reasons, by everyone from elite athletes to the average, occasional exerciser. A common misconception can be that drinking protein shakes will make you bulk up or gain weight, as they’re often used by bodybuilders. In fact, the opposite can be true if they’re used correctly. Here, you’ll discover how protein works to help with weight loss, as well as ideas for how to incorporate them into your diet.

What are protein shakes?

Protein shakes are typically made from protein powder and water. However, you can combine protein powder with endless combinations of liquids and other ingredients to customise your own shake.

Protein powder is a convenient protein source that can be used to help meet your workout goals, or to ensure that you consume enough protein each day. Alternatively, you can purchase high-protein, pre-packaged shakes in grocery, supplement, or health food stores. While you might think of protein shakes as being just for after a weight training session, they can be used throughout the day, in a variety of ways, to supplement your diet.

 

Do protein shakes help weight loss?

Research has shown that high protein diets can be an effective approach to weight loss.1 However, too much protein from animal sources can contribute to extra saturated fat and cholesterol, which is not heart-healthy. Protein powders provide a low-fat, low-cholesterol alternative to eating additional, larger portions of animal-based protein products.

When trying to lose weight, the bottom line is that you need to consume fewer calories than your body burns throughout the day. Everyone’s calorie needs vary depending on body size, body composition, health conditions, and activity levels. Protein shakes can help with weight loss in several different ways, as they can be used:

  • as a dieting tool
  • as a meal replacement
  • to help change body composition

 

How does ghrelin affect hunger?

When it comes to feeling hungry, your hormones are what signal the brain to think that you need to eat. Ghrelin is the hormone in your body that controls your appetite — it’s often called “the hunger hormone”. Higher levels of ghrelin make us feel hungry, while lower levels keep us feeling satisfied.2

When you consume an adequate amount of protein (like 20 grams in a protein shake), the body responds by lowering the level of ghrelin in the body.2

When ghrelin levels are low, the brain stops telling us to feel hungry and seek out food. Research has shown that, the greater the protein in the diet, the lower the levels of ghrelin.3 The lower the level of ghrelin, the less likely you will be to overeat or to crave extra food throughout the day.

 

Is protein helpful for dieting?

Protein, carbs, and fat are all digested slightly differently. Protein is one of the nutrients that actually slows down the digestive process, keeping food in the stomach for longer, which signals the brain to make you feel full and satisfied.2

This slow digestion rate also means that protein doesn’t cause significant changes in blood sugar levels like high-carbohydrate foods do.

A low-sugar and low-fat protein shake can also be a great low-calorie snack alternative. It can keep you feeling more satisfied than a high-carb snack, like a handful of pretzels or a cookie. Additionally, there’s no evidence of any potential side effects of protein supplements in healthy individuals.4

 

Can protein shakes be used as a meal replacement?

Protein shakes are often used to prevent overeating. Sometimes, people choose to make a protein shake instead of consuming a meal. For example, drinking a shake for breakfast instead of eggs and toast.

In this case, you want to make sure that your shake contains other essential nutrients for health, like carbohydrates, fat, vitamins and minerals. Then you can be confident you’re getting a similar nutritive value to eating a full meal.

Protein shakes as meal replacements are a good option for several situations: when someone has trouble controlling portion sizes and easily overeats, when someone might not have time to cook/prepare a balanced meal and would skip a meal instead, or when other healthy options are limited.

 

Can protein shakes change body composition?

Shakes may also be used primarily to increase protein intake when trying to lose fat and gain lean mass. When you exercise and burn calories, but are also consuming less from your diet, the body starts to break down stored fat – as long as it has enough protein.4

It may sound confusing that gaining mass can lead to weight loss, but the more muscle (lean mass) your body has, the more energy (calories) it burns. Plus, when you’re burning calories during intense workouts, protein shakes not only help your muscles to repair, but also prevent their breakdown. This helps your body to burn fat instead.3

Using protein powder in addition to exercise that builds muscle can help lead to these long-term body composition changes.5

 

How much weight protein do you need for weight loss?

If you’re looking to lose weight and preserve muscle, then you will definitely be looking to eat a diet that’s higher in protein. When you’re in a calorie deficit, your body can break down your muscles for energy when it runs out of other sources. To prevent this, consuming 1.4 – 2.0 g/kg body weight has been shown to be sufficient in those who regularly exercise.6

 

When should you drink a protein shake for weight loss?

The timing of your protein shake depends on where it fits in with your goals and your planned meals for the day. If the protein shake is designed to replace a meal, you would simply have it at that mealtime.

If you are consuming protein to help you gain muscle, it’s best to have after your workout, and for up to 24 hours after.5 If you’re using low-calories shakes to feel full and satisfied, it might be most useful to have them between meals. You can tailor this depending on when you usually feel the hungriest and need help avoiding the temptation of unhealthy snacks!

In addition to the to suppressing ghrelin and slowing from a protein shake, shakes are often high in liquid content. Liquids reach your stomach faster than food, and a shake is typically comprised of at least 8-12 ounces of liquid. The volume of this fills your stomach and can help you to feel satisfied quickly.

 

What are some protein shake recipes?

If you’re replacing a meal with a shake, try including a good balance of macro- and micronutrients by adding some healthy fats and carbohydrates too. Here are a few ideas to get you started — two meal replacement smoothies, a post-workout shake, and a diet shake, designed to be used as a snack.

  • Green Protein Meal Replacement Smoothie: Add spinach, berries, and avocado to a blender cup with your favourite protein powder. Mix with water, milk (for more protein), or non-dairy milk and blend for a refreshing smoothie.

  • Banana Nut Meal Replacement Smoothie: Add frozen banana, a spoonful of peanut or almond butter and your favourite protein powder flavour (we love chocolate for this). Then add your choice of milk and blend until smooth. For an extra boost of protein, add some Greek yoghurt.

  • Post-workout shake: If you have a very intense workout and need to refuel after a workout, mix the protein powder with water and consume within 30 minutes of your training. Based on how hard you worked, you might want to choose a protein powder with some carbohydrates to help rebuild your muscle’s energy stores while they repair and grow.

  • Diet shake: Mix a low carb, low-calorie protein powder with a low-calorie liquid, keeping the fat and carbohydrate counts low. This is a filling snack to help resist overeating without consuming too many calories. This can be as simple as adding a scoop of protein powder to water and mixing it in a blender bottle, or adding some flavoured protein powder to leftover coffee and blending with ice for a satisfying frozen coffee treat.

 

What are good protein food sources?

Food (100g) Calories Protein Carbohydrate Fat
Chicken Breast 153 33g 0g 3g
Salmon 159 21g 0g 8g
Tuna 88 19g 0g 1g
Tofu 82 8g 2g 5g
Quinoa 368 14g 64g 6g
Impact Whey Protein 388 72g 7g 8g

 

Do protein shakes work for women’s weight loss?

While many research studies focus on protein shake supplements for men, the benefits can also apply to women who are trying to lose weight. Protein will similarly affect ghrelin levels and slow digestion in women, just like the studies on male subjects have displayed.

However, women are typically smaller in total body mass than men. They may benefit from a lower-calorie protein supplement since they would need fewer total calories throughout the day, especially when trying to lose weight. Remember that your protein powder should only be part of your overall healthy diet pattern.

 

Take home message

Protein shakes can help with weight loss in a variety of ways. From helping to replace high-calorie meals, to keep you full between meals and preventing overeating. Plus, they can help to build muscle and burn fat from your workouts.4

Protein also lowers the levels of the hunger hormone ghrelin, telling the brain that you’re less hungry.

Protein powders can help anyone to maximise the results of a healthy diet and exercise habits, as well as see the weight loss results you’re hoping for. While some pre-made protein shakes are available on the market, be careful to read the labels and check what other ingredients are included. To have the most control over what goes into your protein shakes, make them yourself at home.

Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you’re concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.


  1. Dong, J. Y., Zhang, Z. L., Wang, P. Y., & Qin, L. Q. (2013). Effects of high-protein diets on body weight, glycaemic control, blood lipids and blood pressure in type 2 diabetes: meta-analysis of randomised controlled trials. British Journal of Nutrition110(5), 781-789.
  2. Giezenaar, C., van der Burgh, Y., Lange, K., Hatzinikolas, S., Hausken, T., Jones, K., … & Soenen, S. (2018). Effects of substitution, and adding of carbohydrate and fat to whey-protein on energy intake, appetite, gastric emptying, glucose, insulin, ghrelin, cck and glp-1 in healthy older men—A randomized controlled trial. Nutrients10(2), 113.
  3. Giezenaar, C., Hutchison, A., Luscombe-Marsh, N., Chapman, I., Horowitz, M., & Soenen, S. (2018). Effect of age on blood glucose and plasma insulin, glucagon, ghrelin, CCK, GIP, and GLP-1 responses to whey protein ingestion. Nutrients10(1), 2.
  4. Leidy, H. J., Clifton, P. M., Astrup, A., Wycherley, T. P., Westerterp-Plantenga, M. S., Luscombe-Marsh, N. D., … & Mattes, R. D. (2015). The role of protein in weight loss and maintenance. The American journal of clinical nutrition101(6), 1320S-1329S.
  5. Samal, J. R. K., & Samal, I. R. (2018). Protein Supplements: Pros and Cons. Journal of dietary supplements15(3), 365-371.
  6. Jäger, R., Kerksick, C. M., Campbell, B. I., Cribb, P. J., Wells, S. D., Skwiat, T. M., … & Smith-Ryan, A. E. (2017). International society of sports nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition14(1), 20.


Claire Muszalski

Claire Muszalski

Registered Dietitian

Claire is a Registered Dietitian through the Academy of Nutrition and Dietetics and a board-certified Health and Wellness Coach through the International Consortium for Health and Wellness Coaching. She has a Bachelor of Science in Biology and a Master’s degree in Clinical Dietetics and Nutrition from the University of Pittsburgh.

Talking and writing about food and fitness is at the heart of Claire’s ethos as she loves to use her experience to help others meet their health and wellness goals.

Claire is also a certified indoor cycling instructor and loves the mental and physical boost she gets from regular runs and yoga classes. When she’s not keeping fit herself, she’s cheering on her hometown’s sports teams in Pittsburgh, or cooking for her family in the kitchen.

Find out more about Claire’s experience here.


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