Why protein supplements will make you fat

Protein seems to be a very poorly understood topic, especially among firefighters. I could write for days about this but today’s post is limited to one critical message:

Contrary to popular belief, protein supplements are for weight GAIN, not weight loss. man drink protein shake

If you are hoping to lose weight, or just maintain a healthy weight, you should not be taking in protein powder supplements nor protein shakes or bars.

While protein shakes and bars have been marketed as diet foods, they are not good tools for dieters. People trying to eat fewer calories should be choosing foods that are low in calories but high in volume. Bars and shakes are the opposite: they pack in a lot of calories within a very small volume. For this reason, protein bars were originally developed as meal replacements, and they should stay that way. They are a good thing to carry at work in case you have to skip a meal. But don’t expect to eat something like this as a meal and feel full. Another problem is that they often have too much sugar and fat in them.

So if you’re trying to lose fat but gain muscle at the same time, should you be taking protein supplements?

Even if you are doing resistance training, powder supplements are only needed if you can’t get in enough calories in order to GAIN mass. If you have a little extra fat to spare, those reserves will burn down so your muscles have fuel to hypertrophy (get larger) in response to resistance training. At the end of the day, in order for muscles to hypertrophy, your body just needs enough fuel (calories) to make that happen, and those calories can come in the form of fat, carbohydrates or protein. Moral of the story: Eating more protein does not equal having a muscular physique.

Hopefully you can now correctly answer NO to the question above.

Now I want to hear from you. Have you taken protein supplements and experienced difficulty getting the physique you want? Or have you had success with them?


If you’re not on my list to get more health tips like these, enter your name and email below.

By | 2018-06-01T08:14:30+00:00 April 3rd, 2013|Uncategorized|43 Comments

About the Author:

Dr. Karlie Moore has a PhD in Exercise Science and Nutrition and specializes in firefighter health. She has conducted fitness testing on hundreds of firefighters and has created the most comprehensive online wellness program for fire departments called the FitCulture program. Dr. Moore is also married to a firefighter and so understands their lifestyle and the health challenges associated with it.


  1. Rodney B. Jackson January 21, 2014 at 5:24 pm

    I’ve taken protein powder and gained unwanted weight around my midsection.

    • Megan June 27, 2015 at 6:13 pm

      hi Karlie,
      So now I’m confused. I burn around 600-800 calories a day through 7 miles of running. I also lift 3x a week. I take in around 1250 calories and lately I’ve been adding a 1/2 scoop of Quest protein powder mixed with 1 C skim milk for bfast. Thats 150 calories with ~18 g protein. I’m an 18 yr old female, do you still think that this protein will cause me to gain weight? I’m trying to lose the 10 lbs I put on while in college.

      • Karlie July 17, 2015 at 4:32 pm

        Hi Megan, if you are doing that much exercise then you are likely burning MUCH more calories than the 1250 you are taking in. You could definitely take in another 150 with a shake – I just want to be sure you understand that those calories don’t have to be from a shake. You can just eat 150 calories / 18 grams of protein in real food if you wanted 🙂

    • dante July 2, 2015 at 7:10 am

      I am taking whey powder and working out as well as getting plenty of cardio and have gained weight in my mid section , weight I did not have before.

      I will stop the powder as soon as I run out and switch to muscle milk.

      I never had the issue with muscle milk.

    • Angela December 27, 2016 at 6:40 pm

      Me too. I was dropping weight . Then I started taking the shakes and gain weight.. I was drinking it before my work out. It didn’t help me at all

  2. Christine May 1, 2014 at 2:02 am

    I’ve tried both protein bars and shakes, and I’ve actually put on a few pounds. I want to reach my ideal weight, so I guess that’s going to have to be a no-no from now on. Plus I need to whittle down my waistline so I can lower my BMI. Thanks for the info!

    • Karlie May 1, 2014 at 3:38 am

      you’re welcome Christine!

  3. Shweta May 20, 2014 at 6:29 pm

    Protein shakes was a bad idea for me. Actually ended up gaining 4 kilos (8 pounds) in a span of one month. Even though I eat super carefully always, just introducing this one item in my diet created a havoc. Now I am having a hard time getting rid of this since I am just 5’5” and it shows. Wish I had read this page before! 🙁

    • Manuj March 10, 2016 at 4:39 pm

      Yeh dude… Same with me. I started eating protein supplement to increase my weight training capacity. I easily increased it.. but now since i left gymming .. I have become way too heavy. No more muscles left… Only fats.. it sucks..

  4. Jared October 22, 2014 at 3:07 pm

    I’ve been using protein shakes and bars (the kind you get at Costco) for a couple years as both a supplement to lifting weights and as meal replacements. I have had great success with them. Those items are both low in sugar and fat.

    • Karlie October 27, 2014 at 5:10 pm

      Thanks Jared!

  5. Tom October 27, 2014 at 4:14 pm

    I have taken protein supplements as shakes, bars, powder on cereal, the list goes on. At the end of the day (years) (slow learner 🙂 ) none of them have ever worked as promised. What works for me is eating a healthy balanced diet with a high amount of quality protein, and recently not from dairy. A question I have always wondered about is the bodies ability to assimilate or digest protein in the form of a bar, powder, pill? Can you body even use all of that stuff in that concentration or do you just get rid of most of it? I can say that a recent grueling hike went sideways while eating a combination of things including protein bars.

    • Karlie October 27, 2014 at 5:09 pm

      Hi Tom, it’s always best to get your nutrients in the form of whole foods. Research shows we absorb them better that way. Excess protein can be hard on the gut (causing your hike to go “sideways”) and hard on the kidneys because they’ve got to filter all that gunk.

  6. tessafane January 19, 2015 at 1:58 pm

    I have been having MyProtein shake with a banana and almond milk every morning for four months and I have put on 4 kgs.. all around my middle. It goes in the bin today.

    • Karlie January 21, 2015 at 4:46 am

      I’m sorry about those 4 kgs but glad I could help!

    • marie June 21, 2016 at 12:37 pm

      Hi tessafane, I have been having MyProtein shakes with almond milk and raw oats for my breakfast, and one in the afternoon with fruit as a snack, I workout 5-6 times a week. I also noticed my middle getting wider even though I eat really clean and healthy everyday. I stopped taking the shakes about a week ago and my waist has totally shrunk back to where it was, also my legs seem slimmer too and the tops of my arms. My muscle tone is beginning to show through now. I wish I had found this site earlier and read the advice. Its sound advice as so many people share the same viewpoint.


      • Jennifer June 22, 2016 at 9:14 pm

        I started doing a vegan protein shake once a day because I am always on the go and I felt healthy doing it. But sadly I have gained a ton of weight too, nine pounds in two months. 🙁 So now I won’t drink them and wonder how I am going to get all those fruits sand veggies in, so frustrated right now. I hate cooking so this was a nice idea for me – bought the bullet and everything. Oh well….

        • Karlie June 22, 2016 at 9:22 pm

          Hi Jennifer. I know it is a bummer. Was it just fruits and veggies or did you add other stuff to it? It may have been other fillers that added too many calories. If you just did a small serving, and only fruits and veggies, you might be able to get away with it.

          • Anonymous October 28, 2016 at 2:32 am


  7. Anon March 25, 2015 at 9:47 pm

    I’m sorry but you’re completely skewing facts here. Yes protein powders have calories but your typical lean whey protein powder will have around 200calories with 25g protein per scoop and maybe 1g sat fat and 1-5g of carbs. It’s all about the macronutrients and your intake and activity levels.

    Those who work out take proteins due to it’s LIQUID form meaning it can get to the body and cells quicker! If you train hard, make sure your
    Macro’s are right and calories are in line with your goals (surplus to goal mass; deficit to lose mass) you should see results.

    People forgetting calories is the main problem especially In the UK. Eg having 6 cups of tea a day and not realising that’s about half a pint of milk.

    To summarise, if you train HARD (so you can barely move that muscle the next day) a low carb protein shake is the ideal way to recover quickly. It will not make you fat alone. Not training with adequate intensity certainly will make you fat however.

    • Karlie March 26, 2015 at 3:06 am

      Whether you have too much tea, milk or protein doesn’t make a difference- calories are calories. Taking in more calories than you burn, regardless of the source, will result in weight gain.

      • Peter April 8, 2016 at 4:54 pm

        That’s not really correct, I went on a low carb diet and loss many pounds. I can tell you I consumed large amount of calories but still lost weight, as long as I did not exceed the carb limit I could eat as much as I wanted. I did it so there is no question in mind calories are not all the same.

        • Karlie April 12, 2016 at 4:45 am

          You will lose weight initially if you cut out carbs but it’s not a good long term plan. Your body mainly uses carbohydrate for energy (about 40% fat and 60% carbs at rest for most tissues, except your brain ONLY uses carbs/glucose). So when your diet doesn’t have carbs, and glucose isn’t readily available, your body starts dipping into your stored carbohydrate which is called glycogen. Burning down those glycogen reserves causes you to lose weight. However, once those stores are gone, your body will have to create glucose out of fat and protein which results in ketosis and kidney stones. It’s like putting the wrong kind of gas in your car. If you’re still taking in too many calories once all the glycogen stores are burned down, even if they’re only in the form of fat and protein, you’ll end up gaining weight back because your body has no problem storing excess of those two as body fat.

          • Dee November 5, 2016 at 8:50 pm

            What should be the daily intake of protein for a 50 some year old female. I work at a med to high intesity daily for one hour.

          • Karlie November 30, 2016 at 4:30 am

            Hi Dee. You need .8 grams of protein per kilogram of body weight

  8. Ashley April 24, 2015 at 2:39 am

    I’m lifting weights and eating clean and I always have a whey protein shake with almond milk before bed if I have worked hard And want to supplement for the sake of new muscle growth. Guess what.

    I’ve lost 10 lbs of fat. You have to work out…drinking protein shake won’t do you any favors. Work out! There is no magic pill or drink, geez.

    • Anonymous July 15, 2015 at 11:18 am

      Well said Ashley. Only taking protein shake won’t help, it all depends on the workout. And yes protein is important to rebuild your muscles after workout. Because your muscles breaks after workout and body needs protein to build them.

      So work hard and play hard.

    • marie June 21, 2016 at 12:41 pm

      instead of having protein shakes now I have a lovely chicken/turkey salad sandwich, ive found I much fuller from actually eating rather than drinking, I will save money too. 🙂

  9. MollyinPhilly July 22, 2016 at 11:54 pm

    I have had an injury which limits the number of work outs a week to only 3. So, I’m filling in with moderate elliptical cardio. I am still not losing the weight I’ve gained from vegan protein shakes everyday even if it’s a light or no workout day. After reading everyone’s comments it looks like I should skip the protein until I get back to a daily routine.

  10. LittleTiern August 26, 2016 at 7:38 pm

    HOLY WOW! This article and the feedback from the comments are a game changer. I’ve been working out consistently (for the first time in my life!) for the past almost 6 months. Cardio (spin classes, run/walk combo,), HIIT classes, resistance and weight training and actually gained weight. I eat very healthy with the exception of a couple dinners a week, and even those are “bad” just not as good. I make a smoothie every morning with oats, greek yogurt, ginger, cacao nibs, either a berry or tropical fruit blend, banana, either coconut milk or orange juice base and the organic superfood acai and goji berry smoothie protein powder. I’ve gained almost ten pounds!! All in my belly. I just ran out of the mix and will NOT be replacing it. Question; am I adding too much to the smoothie in general? I did add chia seeds this morning, thinking I was missing the protein from the powder and now I’m worried the (what I thought was) the healthiest thing I eat all day is actually holding me back!

    • Karlie August 30, 2016 at 8:57 pm

      Your hunch about adding too much to your smoothie might be right. I would suggest cutting back and seeing if that helps. Good luck!

  11. mary February 27, 2017 at 1:33 pm

    I used protein shake for about 3 weeks only and sporadically. I went only through 1/3 of the container and in two weeks i gained 4 kilos. 9 months pass by and I have yet to lose the weight. Agree with everybody else. I have gained the weight around mid section.
    Any recommendations? should i give it more time to lose the unwanted weight? I exercise pretty regularly as well, about a couple of hours every day.
    Feel frustrated at the weight gain. :((((

  12. Lyndy ODonnell April 8, 2017 at 6:58 pm

    I have a low carb EAS protein drink mixed with low carb green powder drink, blueberries, flax seed, almond milk, in the morning. I have a green salad for lunch. I snack on 2-3 of nuts at dinner. More food for me at this point is too much. I am a 57 yr young female.
    I walk 30 min a day with some weights. I am not losing weight. What am I doing wrong?

    • Karlie Moore July 24, 2017 at 9:11 pm

      Hi Lyndy, I would suggest taking out the shake and replacing it with whole foods. You’ll be taking in a lot fewer calories that way. Make sure you’re lifting heavy enough weights that it feels very challenging. You could also walk more than 30 minutes.

  13. Kirk Landau June 6, 2017 at 1:02 am

    This is so stupid. You need to get adequate protein or you will lose muscle. Protein shakes are one of many ways to do this. Protein shakes have practically zero fat and zero carbs, so they’re an excellent source of pure protein. They won’t magically make you fat. If you’re gaining fat it means that you’re eating too many calories overall. Use an online calculator to figure out how many calories you should be consuming (based on age, gender, activity levels, etc) in order to lose weight. Then track your calories throughout your day and make the necessary adjustments. It’s literally that simple.

  14. Manasie July 9, 2017 at 4:32 am

    I have gained 10 pounds in span of 6 months even after doing my cardio and HIIT religiously and eating clean… I am going to stop with that protein powder from today itself… hoping it will help lose those pounds…

  15. Michael July 26, 2017 at 3:53 am

    I eat around 1200 calories. And do bicep curls an adequate amount. If I consume around 90 grams of protein a day in powder, will I get fat? I’m 15 and weigh about 145 at 5”8. I also am very careful with my sugar intake at around 40 grams a day

    • Karlie Moore August 8, 2017 at 11:34 pm

      Hi Michael, that is a lot of protein and over time can become difficult for your kidneys to filter. The recommended amount of protein for a 145 person is 52.2 grams and keep in mind that you’re probably getting at least that with the food you’re eating. If you want to gain mass, it would be healthier to use a high calorie supplement that is equal in carbs and protein rather than all protein. 1200 calories is not very much for a growing 15 year old so you might want to consider taking in more calories (and that can be with food and/or high calorie supplement powders), especially if you want to build some muscle.

  16. Anonymous September 13, 2017 at 5:32 pm

    Doc, here’s my experience. High protein/low carb worked awesome for me in the short term. Short is relative…it worked for about 3-4 years I guess. I got really lean and lost weight, down to about 188 at my lowest. I was in my late 40’s and I’m about 5’9″.

    I started gaining unwanted fat and the losses seemed harder to come by. I also noticed that I couldn’t hang with the younger guys during our workouts as well. I just chocked it up to approaching 50.

    I had shoulder surgery in the fall of 2015 and was out of commission for 6 months, sitting around doing nothing but eating junk. I gained up to a little under 225#. When the Ortho turned me loose to workout again I went back to my old tricks; high protein, low carb, moderate (good) fats, HIIT and strength routines but this time it wasn’t working at all.

    Got back into the station in June of 2016 and I’ve struggled for the past year trying to drop the weight. 218# is as low as I’ve been able to get before I plateau. I tried adding carbs back in (people were telling me that I wasn’t eating ENOUGH), I tried the Body for Life style diet, I even tried going ketonic for a while….218# was it.

    Finally, I realized that what my primary care physician was telling was significant. I was pre-diabetic, insulin resistant, blood sugar was consistently too high. What confused me though was that my low carb high protein diet should have been working. That’s what all the diabetic experts would tell you to do but it wasn’t getting it done.

    So I did some googling and YouTube watching. Here is what has started working for me and also some full blown diabetic friends of mine.

    HIGH carb eating but plant based, low glycemic. I’m eating a ton of fruit, beans, salads, whole grains, brown rice, sweet potatoes, etc, etc. My blood sugar had been being 130+ in the mornings fasted now its around 100. I started dropping weight immediately, down to my 218# the first week and today, about 3 weeks in, I was at 212#!!!

    My friend, another firefighter who has struggled with diabetes for 20 years, tried it. He can barely keep his sugar high enough and is taking way less insulin everyday. He told me that he doesn’t think he can continue eating this way because he is afraid his sugar will bottom out on a call at 3:00am!

    • Karlie Moore September 13, 2017 at 8:31 pm

      That is definitely a very healthy way to eat! I promote eating all the foods you’ve described in both my 60 Day Slim Down Challenge and my online wellness program for departments. I’m very happy for you that you’ve found this new way of eating that’s going to help you stay thin, avoid diabetes and live a longer, higher quality life! Thanks for sharing you story.

  17. Sandra June 4, 2018 at 11:36 pm

    Thanks for this article! I am a vegetarian, work out about 5 or 6 times a week, and am not seeing weightless results. Do you think in my case introduction of a high protein low sugar supplement could help me? Or does all whey protein = weight gain?

    • Karlie Moore June 6, 2018 at 6:03 pm

      Hi Sandra, unfortunately I wouldn’t be able to say without seeing a nutritional analysis of your diet. You can do your own here and see how many calories and protein you are already taking in: https://www.myfitnesspal.com/

    • Olav July 18, 2018 at 5:45 am

      Hi Sandra, I’ll chime in with my experiences, given that I’ve been a vegetarian for 20 years, and occassionally have struggled with maintaining my weight. But for the last year or so it seems like I have found my rythm. Vegetarianism in itself is not a silver bullett.

      I have found out that weight loss is both easy and complicated at the same time.

      The easy part: It’s just about eating less calories than you consume. It ain’t more complicated than that. Eat less than you consume during a day, and you will lose weight. Eat the same amount of calories as you consume, and you will maintain your weight. Eat more calories, and you will gain weight.

      Now the difficult part:
      Eating less than calories than you consume is suprisingly difficult. For two reasons:
      1. It may make you go around hungry, which can be frustrating.
      2. It’s actually very difficult to keep track of calories. Studies have shown that almost all people under-report their calorie intake.

      I have figured out some tricks which have worked for me, though. The first trick is to do what is recommended in this article – to eat foods that are high in volume but low in calories. This fills me up, and makes me eat less calories in total. If if get cravings, my go to snack has become raw carrots, raw broccoli or an apple. I also avoid protein shakes, as I have found that they provide lots of calories, but don’t fill me up. So drinking protein shakes make me gain weight.

      For my protein needs, I rely on eggs as the main source, and eat at least one, usually two or three per day. (the idea that eggs are bad because of cholestorol is probably a myth, according to the studies I’ve read). I find that this fills me up, and makes me feel less hungry. This won’t work if you’re a vegan, though. I have been thinking of covering more of my protein needs through soy/tofu though, partly out of considerations for the climate and animal welfare (that soy is bad is another ill-founded myth).

      For calorie counting, I have given up on it. What I do instead is to weigh myself every single morning. Daily! Then I can easily see if I can go up or down. If I go up one morning, I simply eat less that day. Hard, but it works.

      The other thing I have found that works well, is intermittent fasting. Google it. I do a “semi-fast”, and one or two days a week I will typically eat very lean, and eat mostly oats and raw veggies, and not eat anything after lunch till the next day. It’s hard, but for one day a week it’s doable, and it actually makes it much easier to maintain my weight.

      I have also made a habit of not eating before bedtime – I try to go to bed feeling just a little bit hungry. I still fall asleep, and my body racalibrates itself during the night kind of, and I wake up feeling good.

      Hope this was helpful. Good luck!

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