Plant Based Diet and Weight Gain – 4 Common Mistakes

LIMITED TIME OFFER: Join the planet friendly plant based diet!

Start today for only $9.49

So, you’ve taken the plunge and started eating plant based diet in the hope of doing something great for yourself in terms of health, fitness, energy, or maybe in the hope of losing weight with plant foods. All this, alongside the many other amazing benefits that this lifestyle can bring; however, you may also find that the plant based diet and weight gain can be quite a common problem if you’re making any of these 4 common mistakes.

Well, unfortunately the plant based diet and weight gain can be quite common at the off set, and this can be down to a number of reasons that are luckily very easily fixed.

Possible causes of weight gain on the plant based diet


You’ve cleared all the junk and animal products out of your life and are cramming in lots of fruits, veggies, nuts, seeds and other healthy whole foods like you’ve been told to do. However, all these foods can kick-start detoxification when animal products are cut out as well, which is all good of course, but can make you crazy hungry as one of its side effects. I know it did me!

I guess it’s a period of cold turkey, which ultimately makes you eat MORE food to make yourself feel better. You will more than likely experience the below symptoms if you were eating before this a bad diet full of lots of refined sugars, carbs, dairy, alcohol and caffeine and then suddenly did a 360 degree turn-around into a fully whole food plant based diet.

Symptoms of detox are:

  • TIREDNESS – which in itself can make your body crave carb-heavy foods for energy.
  • HEADACHES – These can be due to any number of foods your body may be missing that it usually has. For instance, caffeine, wheat, gluten, dairy and refined sugars can be addictive.
  • FAINTNESS – Can be caused by headaches and low energy.
  • SKIN BREAKOUTS – Such as spots, due to the release of toxins.

The good news is, these symptoms should ALL clear up within a week of two (but it can sometimes take a couple of months for your actual digestive system to fully adjust) and then you will start to truly reap the benefits of amazing plant foods. BUT, this is a period where you can be susceptible to gaining weight in a bid to make yourself feel better and to quash cravings and alleviate detox symptoms. However, as your body becomes used to its new diet it will start showing you some love.


mixed nuts

You’ve basically stopped eating meat, fish and dairy (two major sources of protein) but haven’t a clue what to replace them with and consequently you aren’t reaching your protein quota. OR, you may simply be replacing them by just adding more strarchy and carby foods to your diet instead, such as having extra potatoes, pasta or rice instead of the protein element of a meal.

This scenario often happens when you are not the primary food prepper in the household, and so you carry on eating the same meals as everybody else minus the meat, fish and dairy. This can spell disaster for your weight because lack of protein in a meal, on top of the fact that it is carb heavy, will make it high GI. You will find this to be especially true if those carbs are refined in the form of white bread, rice and pasta instead of the wholegrain complex carbohydrate versions.

A high GI meal will encourage a high insulin response, meaning those simple sugars from the carbohydrates will be pushed into fat cells, which will of course mean weight gain. To negate this you need to take the time to learn about your plant based macronutrients and ensure you are receiving nutritionally complete meals.

Sources of plant based protein:

  • Pulses, beans, legumes, lentils.
  • Nuts
  • Seeds
  • Soy and soy based products.
  • Quinoa
  • Buckwheat
  • Amaranth
  • Hemp
  • Plant based protein shakes.

Along with all the above, there are many new food products available in supermarkets that can take the place of animal products. These include sausages, burgers, nut roasts, nut milks, cheeses, yogurts and ready-made meals, so if you are eating with your family you can easily include these in.


You’ve given up animal products, but haven’t really embraced the whole foods plant based thing as it’s designed to be. I actually know vegans that don’t like fruit and veg! In this case you may still be eating lots of junk foods in the form of trans fats, free sugars  takeaways and other junk foods.

This means your diet is still very unhealthy even though it is essentially vegan, and what with the popularity of this way of life there are now even more animal-free junk foods available in all their forms such as ice-creams, pizza, biscuits, cookies, cakes, soda’s, and it seems every take-away joint has plant based offerings these days. This is fantastic news of course, I am not knocking it for a second as it is a great sign of change, but these foods still need to be eaten in moderation if you don’t want to pile on the pounds.


salad and oil

You’ve embraced the healthful plant based lifestyle fully, maybe you were quite into healthy eating before and know a lot about nutrition and how to put a complete meal together with all the elements to keep your body satisfied, but you find you are gaining weight.

This happened to me, and is something I still struggle with if I’m honest, but when I really stared to look at my diet more closely I realised that I was simply eating too many calories overall. At the end of the day body weight is pretty much a simple science of calories in versus calories burnt off and I was simply just eating too many calories (I like my food, what can I say).

Portion Control

Nuts, seeds, ‘healthy fats’, high cacao chocolate, dried fruits, and peanut butter are among my favorite plant based foods and were something that I really went to town on when I first went completely plant based. But if I had a nut roast instead of lean meat with a meal I was doubling the calories straight away. Same goes for high calories snacks of nuts and seeds – all super healthy maybe, but HIGH calorie, yes.

So, you really have to watch portion control with high fat foods because the plant based diet will have you naturally reaching for more of them, and this can be an issue. Go for veggie sticks, fresh berries, low sugar fruits, protein smoothies, green smoothies, and these other fantatstic low carb snacks instead of too many fats if you are having problems with your weight.

Avoiding weight gain on a plant based diet

If you want to keep from gaining weight whilst eating plant based foods then try to eat only from this whole foods list, and also eat in moderation all fats.

  • Plant based dairy alternatives such as hemp, soy, coconut, pea, oat and rice milks, cheeses and yogurts. Try to go for no added sugar versions, and avoid products with too many additives. Most of the coconut cheeses and yogurts seem to be pretty clean.
  • Nuts of all kinds; best eaten raw for highest nutrition. Be sure to vary them up as they all contain different nutrients.
  • Seeds, again, best eaten raw and kept varied.
  • Pulses, easier if you buy them canned.
  • Lentils, same.
  • Quinoa
  • Brown rice
  • Buckwheat products such as flakes, grouts, flours and pasta.
  • Oats
  • Tempeh
  • Tofu
  • Fresh fruits and vegetables.
  • Frozen fruits and vegetables.
  • Salad
  • Corn
  • Polenta
  • Green superfood powders for extra nutrition and amazing skin. (See complete list).
  • Plant based protein powders for snacks and days you find it hard to make nutritionally complete meals.
  • Nutritional yeast flakes – cheesy and full of B-Vitamins.
  • If you have a sweet tooth, then make your own homemade desserts out of mostly whole food ingredients. Desserts don’t have to be a rarity or a treat when you pay attention to ingredients and steer clear of refined sugars and fats.

Plant based proteins

mixed beans

Always make sure you get some good protein sources into all of your meals, as you need it to keep your muscle mass up and also your weight down. Not eating enough quality protein can leave you hungry and unsated after a meal, ultimately making you consume a lot more calories through extra snacking afterwards.

You will also need to be sure you are meeting protein needs if you are doing lots of physical exercise, as your need will be higher. This is easy to do as long as you eat good amounts from list the below with all your main meals.

  • SOY PRODUCTS (in moderation) including mince, tofu, tempeh, burgers, sausages, milks and cheeses. As mentioned before, try to go for products that are organic or don’t have too many additives. You will need want to vary your protein sources every day, as too much soy isn’t good for everybody due to the fact it is estrogenic.
  • PEA PROTEIN – I’m finding pea protein in lots of new plant based products on the supermarket shelves right now, which is great as peas are highly nutritious and have lots of other health benefits. I’ve seen pea milk and pea protein meat substitutes so far, and in my opinion it is a tastier meat and milk substitute than soy.
  • BEANS – Pulses are packed full of protein, fiber, antioxidants and phytochemicals all crucial on the vegan diet. Eat in abundance kidney, black, cannellini, borlotti, pinto and butter beans. Great in homemade burgers.
  • LENTILS – All lentils are highly nutritious and pack a big protein punch, plus they are versatile and can be thrown into veggie stews and soups.
  • NUTS – The highest protein nuts are peanuts and almonds, but you should eat all kinds in moderation and preferably raw. Peanut butter is a great low GI snack on an oat cake for instance. Or, you can use them in stir-fries, salads, to make creamy sauces for pasta, or as a snack with a little dried, no added sugar fruit.
  • SEEDS – Again, seeds can be used in moderation in the same way as nuts, and all different types should be alternated to obtain all their nutritional profiles.
  • BUCKWHEAT – The flour from buckwheat can be used in baking and pancakes, flakes can be made into a porridge, and grouts can be used as a rice substitute or in a tasty breakfast granola.
  • QUINOA – A great protein rich rice substitute that also contains essential fatty acids, making it the ultimate superfood. It’s amazing how good for you this little seed is, and it can come in the form of flours and flakes for baking and cooking, the same as buckwheat.
  • AMARANTH – Depending on where you live you may or may not have heard of this nutritious seed, but either way you can usually get it in most health food shops and it can be used as a side dish instead of your usual carbs, or even as a porridge. Often comes puffed as a breakfast cereal too.
  • HEMP – is a fantastic source of full spectrum amino acids that ALSO contains EFFA’s, so another all-round superfood. Harder to add to meals as it normally only comes in seeds or powder form, but great for smoothies and snacks.

Obtaining a complete amino acid profile

Something you must be educated about when going plant based or vegan is plant protein amino acids. Many plants are not a complete protein source, which means they may be lower on certain essential amino acids than naturally ‘complete’ animal products.

Therefore, it is very worthwhile eating at least a portion or two a day of the following few plant foods that do contain a full amino profile on their own, or you can mix them up with other protein sources for variety. These are:-

  • HEMP

The importance of exercise

woman using dumbells

Lastly, if you are gaining weight on your plant based diet then you should up your exercise regime. Being plant based and doing all these healthful things for your body wouldn’t be complete without physical fitness, which is of course the cornerstone of good health.

You will find that you will get fitter faster, recover faster, and have more energy to go for longer periods when your diet is filled with lots of antioxidant rich plant foods. This is party due to the eating of lots of anti inflammatory foods and cleaning out your system.

A good mix of cardio and weight bearing will keep you strong, fit and within your ideal BMI, and this will be an amazing compliment to a whole food diet.


Take the time to learn about food combining, plant proteins, and putting together a complete meal and you can’t go far wrong with this lifestyle. And do remember that even the most healthful of plant or vegan diets will more than likely need some nutritional extras to fill in the gaps, so please check out the 3 crucial nutrients that can be missing on a plant based diet.

Thanks for reading, and I hope I have pinpointed the reasons why you may be gaining weight on a plant diet and you can rectify it fast. Please feel free to like and share this post with your plant based friends so they don’t make the same mistakes. 

And before you leave, don’t forget to join up belowfor more exciting plant based news, tips and much more straight to your inbox!

Share this post with your friends.

8 thoughts on “Plant Based Diet and Weight Gain – 4 Common Mistakes”

  1. This is really useful information. I’m not personally on a plant based diet at the moment, but I have cut out a lot of bad. I eat a lot more green and drink a lot more water and have noticed those symptoms, tired, headache, faint and mood swings. Now I understand where they are coming from. I know you will be helping many people here. Thank you for that.

    1. Hi Tracey,
      I’m sorry you’re getting detox symptoms as I know they can really suck. Just handle in there and they will most definitely go away. You’re more than likely craving sugars as that can make you feel rubbish for a while.

      Once you have worked past them you will feel so much better, sleep better, and have loads more energy so it’s well worth the wait.

  2. Hi Stefanie, I found this post really interesting as I also follow a plant based diet. I use a lot of quorn based foods such as mince and sausages. I eat plenty of fruits and veg but tend to be a bit narrow sometimes in my choice of veg. Interestingly, I noticed you mentioned vitamin b12 deficiency in a linked post. My GP suspects I may have vitamin b12 deficiency following a routine blood test.

    1. Hi Kathy, that’s awesome you follow the plant based diet and I’m sure you feel great for it.

      If you feel you are missing out on your veg then you should just do a green superfood powder shot every day as it will really help fill in the gaps. Plus, it’s easy to do and you don’t have to think about it too much.

      As for B12, yes, it’s vital to take a supplement or to make sure you are eating lots of B12 fortified foods such as nutritional yeast and most plant milks are usually fortified with it these days.

      If you already have a deficiency then you will definitely need high strength supplementation to get you back on track. Also, you will probably need omega 3 and vitamin D supplements if you are not eating any animal products as these are the things that most vegans can become deficient in.

      Hope this helps. Do let me know if you need any more advice!

  3. This is very informative. Sometimes we can go to the extreme when we take on new ways to stay healthy. With a plant based diet for instance we still have to be mindful of our bodies and make sure we are balancing it out with other nutritional extras as you mentioned.

    I loved your list of how to stay slim on a plant based diet. There are some on that list I was absolutely not aware of and I want to try. You make a great point about having an amino acid profile completed. This can be very helpful because as you mentioned many plants are not a complete protein source.

    You cannot go wrong with following this guide. Thanks for sharing.

    1. Thanks for the compliment Nate, I’m glad you find value in the post.

      I’m always trying to make people aware of plant based proteins and how to obtain complete amino acid profiles as its just so important. It’s something that I didn’t understand fully when I started out, and as an avid exerciser this really had a detrimental effect until I learnt more about food combining.

      So many people are turning to veganism and plant based eating right now, which is great, but they also must do it correctly in order to stay healthy.

  4. Cracking post Stefanie, it always surprises people when they can actually put on weight when they are on a plant based diet.
    As you say portion control is a biggie for me in particular. I will make veggie chilli and can’t resist a mega postion because I know everything in it is healthy. Maybe, I am just greedy.

    I am not a vegetarian or a vegan but changing to a more plant based diet helped me lose 56lb last year. Sticking to this way of eating has also helped me keep it off for 7 months. This has never happened before I have always put weight back on.

    Exercise is very important too of course as it burns of the calories and keeps the weight down. Thank you for this excellent post.

    1. Hi Frank,
      I’m the same too, when I first started eating healthily I piled on the pounds in the belief I could eat whatever I liked as long as it was healthy. How wrong I was! I probably gained a stone really fast which was quite shocking as I just couldn’t understand it. Anyway, I kind of have it under control, but I still love my food a bit too much, guess I always will ha ha.

      It’s surprising how many people have the same story to tell which is why I thought I needed to cover it in a post.

      That’s amazing that you have managed to lose and keep off your weight through eating more whole plant foods. It really does work when you get it right.

Leave a Comment

LIMITED TIME OFFER: Join the planet friendly plant based diet!

Start today for only $1

Shopping Cart

Go ahead and sign up to our mailing list to get a FREE eBook PLUS our delicious recipes straight to your inbox.
You won't regret it!

Wait! Before You Leave, Grab yourself a FREE Fast & Easy Recipes eBook...

Scroll to Top