How I Built Muscle in 30 Days on a Vegetarian Diet

Scroll this

In February of this year, I set a goal to eat a vegetarian diet for 30 consecutive days and am happy to report that…drum roll…I completed it successfully! Over the past few years, I’ve been curious to further explore vegetarianism and veganism to understand how each respective diet would impact my performance (cognitive and training-wise), body composition, and my energy levels/mood.

My interest in veganism piqued in 2018 after reading Rich Roll’s Finding Ultra and Scott Jurek’s Eat and Run. Both Rich and Scott are endurance athletes–their books go in-depth on how veganism positively impacted their training and race performance. Scott Jurek is arguably one of the best endurance athletes of all time; he’s competed and come out on top in some of the most grueling endurance races in the world, including the Badwater 135-Mile Ultramarathon and the Western States 100-Mile (which he won 7 times in a row). Rich Roll has quite the track record too. He was a top finisher in the 2008 and 2009 Ultraman World Championships and also has the monumental achievement of what him and his friend Jason Lester coined the ‘EPIC5 Challenge’ under his belt: completing 5 ironman-distance triathlons on 5 Hawaiian Islands in less than a week. Between these two, there’s no shortage of inspiration to draw from. In 2018, I attempted to go full vegan, but only made it to day 20 before I decided to throw in the towel.

3 years after my first vegan attempt, I decided to give this another go but with more realistic parameters. Vegetarianism seemed to be a reasonable steppingstone; I could still consume animal by-products (dairy and eggs), while also rotating some vegan-only days into the mix. Less rigidity would be good for me. Akin to a scientist, I positioned this challenge as more of an experiment with some questions fuelled by my innate curiosity: 

How would this diet impact my running and training performance?

How would this affect my body composition? Would I be able to get enough protein to support muscle growth? (an annoying question for vegetarians/vegans, but still a question I wanted to explore nonetheless)

How does this diet impact my mood and energy levels?

I also wanted to challenge myself in a few other aspects:

  • Learn new vegan and vegetarian recipes to incorporate into my diet. There’s a myth that vegetarian and vegan diets can be bland or boring (which isn’t true in the least, by the way).
  • Research plant-based protein and protein combinations to ensure I get all 9 essential amino acids.
  • See if I could do it and stick with it for 30 days. If you’ve read any of my past writing, you’ll probably know how much I love 30-day challenges.
  • Lastly, I wanted to try this diet from a sustainability standpoint and to try and do my part in limiting meat consumption.

My Fitness Goals

Before we dive in, I want to share with you my current fitness goals to provide a bit more context for the diet/training parts of the post. Over the last 6 months or so, I’ve hit a bit of a genetic ceiling with my body recomposition. While I’m still able to reduce my body fat, I’ve found it harder and harder to put on more muscle – particularly on my upper body. My physique changes have been incremental (at best), even though I’m still following a progressive training plan and using adequate nutrition to support my goals.

So with that being said, I didn’t go into this challenge with any particular physique goals per se, but more so wanted to explore my curiosity–if I kept my training consistent, but swapped in a meatless-diet, how would this affect my body composition? So, you could say that my goal was to maintain my weight and existing physique, but if I was able to add a bit more muscle while trimming down on the fat, then great!

Counting Macros & Calories

For most of the challenge, I wanted to ensure I hit my daily protein goal with the help of myfitnesspal, an app that helps you keep track of what you’re eating at a glance. I didn’t plan specific days to eat in a caloric surplus or deficit, I ate intuitively over the course of the month. Some days I’d eat in a surplus, others in a deficit, and some closer to my maintenance calories. I just listened to my body’s hunger signals and took it from there. 


As I mentioned before, probably one of the most annoying questions vegetarians and vegans get asked has to do with their protein intake. I admit that I also had this question – where and how would I get the bulk of my daily protein if I’m no longer consuming meat? 

I don’t want to rehash exactly what I wrote in my last post, but I do think calculating your daily protein intake is very important to support any sort of healthy diet and especially for body recomp goals. Therefore, it’s worth the repetition. 

There are an abundance of formulas out there for calculating how much protein you should have in a day and while I’ll save this deep dive for another post, there is somewhat of a consensus amongst some of the most credible, science-based fitness professionals on the web (when it comes body recomposition, building muscle and losing body fat) . My go-tos include Jeff Nippard, Menno Henselmens, and Dr. Eric Helms.  The range that all of these professionals (backed by recent scientific-based research) is: 1.8–2.7 g/kg of body weight. However, most advise going on the higher end and at least >2 g/kg of your body weight.

Since I am on a progressive strength training plan and incorporate a hell of a lot of cardio in my day, I aim for 2.3-2.5g/kg per day. My weight before the diet was 139 lbs, so I calculated my protein intake goals as follows:

63kg (139 lbs) x 2.3g protein = ~145 g/day
63kg (139 lbs) x 2.5g protein = 158 g/day
My daily protein target is 145–158 g/day

What I suggest is to pick a range rather than a fixed number to shoot for. Again, just take your body weight and multiply it by the grams per day and voila, you got your range.

Protein is the only macro I really pay attention to on any specific plan because it provides the building blocks behind any nutrition and training plan. In Jeff Nippard’s video, The Science Behind High Protein Diet, he explains that the main reason why a high protein diet is good for body recomp is:

1.The thermal effect – Your body burns about 2x the calories digesting protein as it does with carbs or fat.

2. Increased satiety – Protein keeps you fuller, longer than fat and carbs with the same calorie intake.

3. The muscle building properties – this should be ubiquitous by now.

A quick disclaimer: The myth “high protein diet” being bad for your kidneys or bones has been disproven. Here’s a meta-analysis of 28 studies that confirm this finding. However, it could be detrimental and worsen kidney function for people that already have a pre-existing kidney disease or condition. An important caveat to mention.

The Protein Guide

During the month of February, I was talking to my mom about the challenge and the protein component and she mentioned that she too wanted to incorporate more protein in her diet. We went through the same exercise as I described above, calculating her daily protein intake based on her weight. 

To assist her in adding more protein-rich foods in her diet, I put together a protein guide/one-pager for my mom that currently lives on the fridge beside her daily protein targets. Since I also wanted to hit my protein goals, I created my own that included vegetarian and vegan protein sources only. Here’s what the guide looked like and if you haven’t done this before, I highly recommend you give it a try:

vegetarian protein guide

Who would have thought that adding 2 tablespoons of tzatziki with my veggie burger and 1 tbsp of nutritional yeast on top of my beloved popcorn would bump up my meal by 4-5 grams of protein? This guide helped me sneak in little protein sources here and there with some of my larger meals. Funny enough, I actually shared the guide I made for my mom in my Instagram stories and a ton of people direct messaged me to email them a copy (which I did of course). Oh, and if you want a copy too, just email me and I’ll send’er over 🙂

The staple protein sources I included that either provided all 9 essential amino acids or provided the requirements in combination with one another included: 

Nutritional Yeast 
Eggs & egg whites
Vegan protein powder
Raw nuts + seeds (chia, pumpkin, almonds mostly)
Peanut butter & whole wheat crackers – complete proteins if combined together
Rice & beans – complete proteins if combined together
Hummus & pita – complete proteins if combined together

The Experience of 30 Days Vegetarian

Now we get into the ‘meat and potatoes’, I mean ‘potatoes’ of the challenge (I forgot that I was vegetarian this month). AKA the actual experience. With the start of any new challenge, I always feel excited and extra motivated at the start–something, I’m sure, we can all relate to. 

I went in with high hopes and expectations for myself. I wanted to try new recipes almost every day, eat healthier, and live my best, plant-based life.

As with any new goal, my excitement and motivation came in small doses after the first week. My big plans of diversifying my recipes, trying an abundance of new flavours, and exploring all the vegan influencer feeds had to offer, fell by the wayside. Here’s the reality: I made a grand total of four new recipes over the 30 days, got lazy, then pretty much just ate the same thing every day. 

However, I did buy some new foods that hadn’t made a consistent appearance in my diet before, which did spice up my repetitive meals a bit. These included: nutritional yeast, spirulina, tempeh, soy products, and new protein bars. I liked the diversity the soy products had to offer, since it meant I could have soy meatballs, veggie burgers, tofurkey, soy sausages…the list goes. 

Unfortunately for me, within the first week of the challenge I experienced a very unpleasant surprise: the emergence of acne all over my face and back. I’m not even talking small little pimps, I’m talking cystic acne on my back and shoulders. I felt like a hormonal teenager who was experiencing her first period.

I’m in my 30’s now, so this is a throwback I don’t want to deal with anymore.

I then played the tantalizing game of which food item is making me look like a hormonal teenager? To approach this million-dollar question, I did some research on my good ol’, reliable friend, Google. Of course, many of the items I searched returned controversial answers. There were numerous studies on how spirulina was a miracle food for the skin, while others said to stay away from algae entirely–it can cause bad breakouts.

Some protein bars make my skin break-out and I had just tried a new brand. Was it the protein bars?

Oh yeah, and I had just bought a new pre-workout supplement…could that be the culprit? 

I slowly started eliminating one thing at a time: the spirulina, nope. The pre-workout, nope. The protein bars, nope. What else could it be? 

I was at my sister’s place one Saturday afternoon and told her about my predicament in which she immediately replied, “oh, it’s 100% the soy”. I did do a bit of investigation on the subject and similar to the controversies surrounding spirulina, I couldn’t find any studies on the direct correlation between soy and hormonal acne. I also ate soy products in the past (soy milk, edamame, etc.), but never saw a relationship between that and my skin. I did end up removing the processed soy products (ie. veggie burgers, soy meatballs, etc.) and also tofu and noticed a huge improvement in my skin. Whether it was an allergy or intolerance, I’m not sure, but I can safely conclude that soy-based products aren’t great for giving me that clear, glowing complexion. Speaking of soy, when researching the hormonal effects, I went into a bit of rabbit hole on the controversies regarding its effect on male and female sex hormones.

The Soy Debate 

Soy was my first choice in a meat substitute as it contains all 9 essential amino acids and was thus an easy way to help me achieve my protein targets. Soy is a hot debated topic amongst the scientific community on whether it can be linked to health benefits or rather, have has a more deleterious effect. I was enlightened to learn that making a blanket statement about soy is a mistake. 

I found an interesting article from Harvard School of Public Health that explained the uniqueness of soy compared to other foods in the human diet. Soy contains high concentrations of isoflavones–a plant compound that contains estrogen and actually acts similar to human estrogen, but has much weaker effects.

Isoflavones have differing effects on the body depending on a few of the following factors:

  • Type of study: the effects differ from animals and humans — thus we shouldn’t draw conclusive evidence on the bodily effects on humans from studies conducted on animals.
  • Hormone levels: the effects can vary based on current hormone levels in the body. Premenopausal women have larger levels of estradiol than postmenopausal women, for instance.
  • Type of soy products: there isn’t just one class and each can have a different effect on the body. Soy protein, veggie burgers, and tofu for example, can affect us differently.

Soy Effects on Men and Women

There’s another myth being circulated that consuming soy affects men’s testosterone levels and can also increase estrogen levels in women. I also believed this myth, but turns out, isn’t true. A meta-analysis of 38 clinical studies concluded that soy/isoflavones do not affect male testosterone levels.

Another 2009 meta-analysis conducted on pre and post-menopausal women concluded that there were no statistically significant impacts of, the ingestion of isoflavones on female sex hormones. However, it is worth noting that soy can increase the duration of the menstrual cycle (worth it? hmm…I’ll let you decide).

In sum, soy is a great meat substitute as outlined in the protein guide (as long as you don’t have any pre-existing allergies and food intolerances) and is an easy way to hit protein targets. Unless it gives you acne in which case, well, you’ll have to weigh out that trade-off.

Now that we got some of the controversies and myths cleared up, it’s time to jump into the fun part. A full day of eating…

A Full Day of Eating in a Surplus

To be quite honest, I did find it difficult to eat in a surplus while on this diet. I was eating so many foods that were choked full of dietary fibre and high in satiety that it was a struggle to eat a lot. I mentioned earlier that I had big plans to try new recipes, with the first on my list being a spirulina smoothie bowl (depicted below):

Beautiful, right? The mango sunk to the bottom and the peanut butter decor did not spread out as evenly as planned. Yes, I admit that my attempt did resemble swamp trash. My mom summed up the look of the dish nicely by walking into the kitchen and describing my creation as repulsive. In fact, she said verbatim, “holy shit that looks disgusting.” Thanks Kate.  When I posted my sad smoothie bowl creation to the gram, someone commented that it looked like “abstract art.” Ya’ll are getting creative in your insults.

Anyways, let’s get back into a full day of eating which is always a fun time (at least for me). In my last full day of eating vegetarian post, I showcased what I ate in a day in a caloric deficit. In this post, I’m going to show you a full day of eating in a slight caloric surplus, accompanied by the calorie and macronutrient breakdown:

eating vegetarian in a caloric su

full day of eating in a surplus

As you can tell, some of the meals are the same, but with minor tweaks. For example, I used a different protein powder and toppings for these pancakes vs. my other ones. If you are on a meal plan and find it monotonous eating the same thing day in and day out, slight little tweaks like a new flavour of protein powder, different type of nuts or fruit on your oatmeal or different seasonings can give the same dish a whole new flavour. Honestly, if I didn’t do little swaps like this regularly, I would have probably just quit the challenge after the first week.

Results – Performance & Body Composition

While following the vegetarian diet, my training remained consistent. I was running an average of 5-miles 7 days per week and I stuck to my 6-day per week strength training regimen, applying the principles of progressive overload. When I tallied and averaged out my calories at the end of the month, I was in a slight caloric deficit. 

While I didn’t have access to a machine that could measure my before and after lean body mass vs. fat mass, from the qualitative photo journaling approach, I did see some muscle growth predominantly in the upper body. At the end of the challenge, I was up 1.1 lbs (to 140.1 lbs) and from mere observation, I would say it was predominately growth in muscle. 

The photo taken in December was right after I trimmed down a bit during my mini-cut, the January photo reflects when I was eating at maintenance for the most part, and the last photo was taken early March immediately after the vegetarian challenge.

building muscle vegetarian

If you’re one of those people that think vegetarians or vegans can’t build muscle, you may want to rethink your stance. Don’t just take me as a case study, there’s innumerable plant-based body builders that have no trouble putting on size. Jon Venus, Torre Washington, Brian Turner, are just a few examples.

The key here is to make sure that you’re 1, hitting your protein needs (and ensuring you get all 9 essential amino acids holistically throughout the day) and 2, following a progressive training plan. Also, eating in a surplus can help expedite muscle growth, but it typically comes with a bit of fat accumulation on the side.

From a performance perspective, I did experience a clearer mind, more energy in my workouts, and generally better moods (except for when I was PMS’ing of course). I did include many more vegetables in my diet and more fibrous foods that kept me more satiated, which also helped control my appetite and restrict my calorie intake.

Processed soy products are not going to be an option for me moving forward. At least not while I’m premenopausal. 

Closing Remarks

Overall, I did enjoy the challenge and while I did slowly start incorporating meat back into my day-to-day, my diet is still predominantly vegetarian (+80%). Spirulina and nutritional yeast are both foods that are now going to make a regular appearance in my diet and vegan protein powder (in my opinion) makes the best base for protein pancakes. Soy can be a really great meat substitute and protein source, so long as it doesn’t cause you with crazy bouts of acne (like it did for me!)

Leave a Reply

%d bloggers like this: