Getting started: avoid the weakness trap

March 18, 2010

After spending more than ten years volunteering weekly in a vegetarian resource centre, I think I’ve gotten a pretty good handle on the reasons people adopt a plant based diet, and maybe more importantly, why they switch back.  Here’s the number one failure reason I’ve heard:

“I tried going vegan, but I just ended up tired all the time.”

And do you want to know the two biggest tragedies about this?  First of all, I don’t hear about it until it’s too late to do anything, because they’ve already changed back and the actual switch is the hardest part to trigger, and secondly, it wouldn’t have mattered because my first reaction was to get defensive and immediately think “they must be doing something wrong, a vegan diet is full of energy!”

After hearing it enough times and gathering enough data, and yes, swallowing my pride, I’ve come to realize that not everyone automatically succeeds on a plant-based diet, and when it comes to physical weakness and fatigue, it’s usually to do with one or two key factors:

Make sure you eat enough

Let’s suppose you’ve decided you’re going to switch from the most average diet around (which, let’s face it, isn’t terribly healthy) to not just vegan, but ubervegan!  Whole foods, no frying, etc.  You’re not a nutritionist, but you just know that a lot of colourful foods is going to be better for you than that hunk of dead animal with fries on the side.  And the range of flavours!  Incredible!

The problem here is that steamed broccoli simply doesn’t have as many calories as feast of roast beast, at least if you fill your plate the same way you’re used to.  You basically have two options, either dramatically increase your portion sizes or consciously add some more calorie-dense foods to your meal (the typically lower fat content of plant-based foods is usually the culprit in the calorie differential.)

Over time, you’ll have no trouble meeting (and then exceeding, possibly by far) your calorie needs on a plant based diet, but a lot of beginners make the mistake of judging nutritional content by how much of their plate is covered.

This problem is often compounded by one of the side effects of not getting enough calories: you lose weight.  For a lot of us, that’s a good thing, and we’re wired up to keep doing the things that give us rewards, so we’ll continue to eat the way we do, lose weight, and somehow manage to not associate the fatigue with the weight loss.  I know it sounds silly, but when you think you’re eating enough (and the majority of people have no idea how many calories they consume a day, vegan or otherwise,) it’s easy to attribute the weight loss to some magic property of plant-based foods, and not the obvious fact that you’re not consuming enough.

The solution to feeling weak as a new vegan is pretty easy: weigh yourself every day.  If it’s going down, eat more.  As long as you’re eating actual food, which I’ll talk about in a moment, and not, say, potato chips/crisps to meet the deficit, your energy levels will take care of themselves.

Eat well

The other trap that new vegans sometimes run into with weakness is due to an over reliance on processed vegan-friendly transition foods.  This is usually less of a problem than the simple calorie count above, but it’s worth a quick discussion.

While mock meats, cheeses, etc are handy, if you approach veganism by simply replacing animal products with their analogues and keeping everything else the same, you might be doing your body a disservice.  Don’t get me wrong; these foods are really useful, and we still consume them fairly often ourselves, but they’re heavily processed, typically high in sodium, and while I’m not a nutritionist, I can’t recommend them as a significant part of your diet.

Looking at it another way, if you ate nothing but hot dogs all day, you probably wouldn’t expect to feel great.  Why would a diet of primarily veggie dogs be any better?

Try to get yourself on whole foods as soon as possible.  As I suggested in 3 quick tips for getting started as a vegan, you only really need four good recipes to get things going, and you’ll find yourself feeling a lot better right away.

Next steps

Being vegan doesn’t have to mean counting every calorie.  I rarely track my nutrition on a daily basis, but it’s a useful exercise for everyone to do one or two weeks of each year to see where they’re at.  I always find it funny that people will ask me how I get my protein but they don’t have any idea how many grams they themselves consume on any given day.

One free tool I’ve found handy is the nutrition log on Daily Burn.  They’ve got tons of foods in their database, and it’s one of the easiest interfaces I’ve seen.  As I’ve said, you probably don’t need to do this obsessively, but if you’re just getting started on a brand new diet, something like this can be a huge benefit towards making sure you’ve got your bases covered.

And most importantly, if you’re encountering problems with a vegan diet, ask for advice!  There are millions of vegans in North America alone, and they’re probably not all misguided fools surviving on sheer willpower 🙂  Leverage any vegans you know along with the internet, including sites like ours, and set yourself up for success by asking for help before and after you run into problems – I don’t want to run into you a year from now and hear another “I tried it but…” story!

{ 27 comments… read them below or add one }

Mirna Orozco March 24, 2014 at 12:55 am

Started this vegetables, fruits and nuts diet, i will do it for 10 day, but planning to become a vegetarian for health purposes. its being 3 days now, and i feel energy deficient and my head just keep on
pondering, i never had headaches like this in my life, what is going on?

David May 14, 2014 at 2:04 am

@mirna orozco Sounds like you’re having a detox reaction. I’ve been vegetarian now for about six weeks and am gaining, not losing fat. I work out intensely at the gym 3 times a week. It’s a mixed bag: I have less liver discomfort (maybe due to less of a toxic load from factory-farmed meat products here in China, air is already very toxic) but I am feeling sluggish, weak and frankly in need of a ‘good feed’, despite cooking lots of supposedly ‘good veggie food’ from books like Mouthwatering Vegan, Mayim’s Vegan Table, etc. I wanted to stop meat for animal cruelty reasons, my dilemma is that I cannot sustain this feeling as crappy as I now do. Any ideas most welcome.

Dennis May 24, 2014 at 7:06 am

Vitamin B12 is critical for vegans. I take time released 1000mg daily. Also I’ve been making Indian vegetarian reciepes and their bold taste are more satisfying as a meat substitute.

Stephan Pellegrini August 13, 2014 at 4:08 am

I have been a Raw Food Vegan for 4 weeks now and it has been amazing. My energy levels have literally shot through the roof, my gym workouts have doubled with no effort and I feel amazing. A few thing piss me off to hear people say, first the protein issue, I use Garden of Life Protein Powder, 34g of Protein per serving, that is ALOT more than a 8oz steak which is the USDA recommendation. The B12 issue is BS, I take a multi-vitamin and it has 300% of your B12, so way over kill there. And I don’t see the point in being a Vegetarian, they are still consuming animal products which contain casein which causes heart disease, heart attacks and many forms of cancer. Vegan just makes total scenes to me and my body is doing wonderful.

Nate November 5, 2014 at 5:06 pm

Hey just for all you out there who are anemic there are some things you should know:

Iron requires other nutrients to be absorbed. While foods like spinach are high in iron they lack the nutrients to help with absorption. Vitamin C helps with iron absorption, try drinking orange juice when eating iron rich foods.

Supplements may not be absorbed properly either, I would stick to eating lots of foods that naturally contain the nutrients you need. Except perhaps B12 and iodine.

Ann December 23, 2014 at 12:06 pm

Been plant based vegan for 10 months… felt great for awhile, now have had dizzy spells, exhaustion even after waking in a.m., insomnia and some heart racing here and there and feel so discouraged. Taking BComplex supplement, as well as Calcium, D, sometimes zinc, sometimes C, sometimes Kelp. On Thyroid med and Lysinopril as well as asthma med. Any thoughts? The dizziness drives me nuts.

Kori January 21, 2015 at 3:06 pm

I can’t seem to make sense of this. I switched from a meat-heavy standard american diet, over the course of a couple of months, to a mostly vegan diet. I didn’t do anything too extreme, or cold turkey. I eat a mostly whole foods diet, full of fruits, vegetables, whole grains, and a touch of “fake meat and cheese products.” I switched for ethical reasons mostly, but I figured a big perk would be the health benefits. I get the amount of calories I need to, I balance carbs, good fats, nutrient rich veggies and I honestly think I am sort of eating the ideal, responsible vegan diet. I take supplements and drink a lot of water, and yet, somehow, I always feel tired… I have anxiety… I’m GAINING weight (???)… and I just don’t feel like I’m running optimally at ALL. I was once a paleo/low carb enthusiast and my body ran very efficiently on predominately animal products and vegetables. I recently had a huge ethical crisis and could no longer support factory farming. I do NOT want to go back to meat but I hate what is happening to my body!! Please help me!! I’m getting fatter and sicker everyday… this is crazy!

lisa December 13, 2015 at 1:47 pm

Hi. It’s been a week that I started the vegan lifestyle and before that I had an eating disorder. I tried a lot of fad diets and I always ended up with gaining weight. I thought that I should start this new lifestyle but today the end of the first week beeing vegan I’m feeling so tired. I have headache and I’m feeling like the fattest girl in the world. I don’t know what’s wrog or it’s just the vegan lifestyle that doesen’t work for me

jenn June 28, 2016 at 12:51 pm

I want to share a few thoughts in response to those who are having trouble with fatigue and weight gain, oh, and headaches.
An issue I had in the beginning, was the amount of fat that can be consumed in vegan foods. Nuts, seeds, avocados, salad dressings and the use of oils in cooking can make the vegan diet fattening. When I first began eating plant-based, I used all of the above to feel satiated, but I began gaining and not feeling as great. After more research, I began reducing the amount of nuts and other fat dense foods. I began cooking Kamut, barley, and Brown rice mixed with lentils, just all in the rice cooker and this provides me with chewy, filling, satisfaction. I began using broth and water instead of oil in sautéing and getting fat free salad dressings. If the dressing is over 3 grams fat/serving, I dilute it with lemon, lime, a variety of vinegars, herbs and spices, fresh garlic and even some water.
A note about cooking with oil: bringing most cooking oils to a high heat, makes them change chemically and unhealthy, even carcinogenic.
Another pitfall for me, is what I call the snack vegan problem. There are so many great tasting vegan desserts and snacks, but they are usually full of refined foods, sugar, fat and salt. I have a friend who is a vegan and she lives on chips and fries and oily stir-fried or roasted vegetables. She seems fine eating that way, but for me, it leads to feeling miserable.
One more issue that I had was headaches in the beginning. I quit all refined carbs and sugars and my blood sugar went whacky! Luckily, I got some good advice that helped immensely. I don’t normally drink fruit juices (if I’m going to eat fruit, I want all the food value that the whole fruit packs), but I had awful headaches because of plummeting blood glucose. Four ounces of orange juice would usually help in about 15 minutes. If I still had a headache, I added another four.
I hopes this helps some of you!

Jason June 29, 2016 at 4:50 pm

Thanks Jenn! Diluting the dressing is a neat idea, hadn’t thought of that before!

Lisa July 2, 2016 at 8:07 pm

When I eat white rice, white potatoes and other white starchy food on the vegan diet, I gain weight. But when I ditch the white stuff and ate beans and 100% whole grain pasta, I lost weight. If you are trying to lose weight, ease up on the white starchy foods. I will introduce those foods when you have reached your weight loss goal and you are only maintaining. Stick to beans, brown rice, oatmeal, sweet potatoes, quinoa and lots of fiber foods for your meals. And not recommending, but I still lost weight quickly when I added fried plantain (with palm oil) to my beans. Beans and fried plantain is one of my favorite dishes growing up where I’m from.

Nik July 28, 2016 at 9:15 am

I found this right on time, I’m so weak. I will start making a few suggested changes right away. Thank you!!

Ed August 19, 2016 at 5:51 pm

1. GET BLOOD TESTS. There is almost no point in commenting on pages like this, asking for advice about what to do when feeling unwell on a vegan diet, unless you have blood tests. This is true no matter what you eat.

2. That said, a common issue is that people eat too much fat and oil. How much is too much varies, but the point is that we only need about three tablespoons of flax, hemp or algae oil a day to get our essential oils. If you are consuming plenty of, say, olive oil but no flax/hemp/algae, then that’s going to be a problem.

3. Are you getting enough calories overall and having a big breakfast in the 1000 calorie range? Again, we are all different and I know athletic vegans who do great eating a big dinner late at night and having lemon juice for breakfast, but you need to experiment. For me, I can’t feel good throughout the day without a roughly 1000 calorie smoothie in the morning, based on bananas and oats/tapioca, with all sorts of other fruit and things thrown in [basically to make either a green or berry style smoothie].

4. Don’t fall for the fully raw fad. Its not based on any science. Humans have been cooking with fire for over a million years, since at least 800,000 odd years before our Homo Sapiens species arose. If it works for you, great, but don’t be surprised if you try it and don’t feel good over the long term. Sweet potato is king and rice and beans are your friends.

5. Are you eating lots of gluten rich foods? Gluten intolerance is mostly a myth, unless you are actually a Celiac, but feeling drowsy after a big dose of gluten is quite normal. I avoid gluten until my last meal of the day, apart from some oats at breakfast if tapioca is not available [the form of gluten in oats is Celiac friendly, but I really couldn’t say if it has more or less effect on drowsiness].


Saf September 20, 2016 at 11:33 am

For everyone out there who is considering switching from a vegan diet to a vegetarian or meat-based diet, I would suggest that you try something else first if you want to be vegan for ethical reasons – insects.


Yup, it sounds yucky, but they are incredibly nutritious and there are people in non-western parts of the world who eat them and consider them a delicacy. Now, this isn’t vegan, but it still means cows, chickens, pigs and other sentient beings don’t have to suffer so that you can get your nutrients from a natural source. In fact, if you can’t bear the idea of eating whole insects, they even make flour out of crickets which you can add to your baked goods and or your smoothies. That’s the way I’m going to deal with the issues that I may be having from being vegan as I can’t be sure they aren’t from other aspects of my lifestyle. I’ll let you all know how it works out for me.
*If all the people in the world who ate meat ate some form of insects for nutrients instead there would be a lot less suffering and a lot less environmental destruction – my hats off to all the people who try to do the right thing especially when it is difficult!

Jason September 21, 2016 at 12:58 pm

OK, putting aside the fact that you sound like someone who works for a cricket protein company, I don’t see how your argument works vs simply supplementing with vegan protein powders or bars, which *is* vegan, and also means animals don’t have to suffer.

Jess September 24, 2016 at 11:43 am

I saw an add that suggested a 7 day vegan challenge which I tried. I gave up caffeine, meat and dairy all at the same time. I almost instantly noticed improvements in my overall health. I am not eating any less just a varied plant based diet. I have now completed 5 weeks and suddenly I feel anaemic which I noticed 2 days ago. I have had anaemia before during pregnancy so I am familiar with the signs.

Up until now I have noticed nothing but good things since changing to a plant based diet. I am incorporating things like and chlorella into my diet along with raw ingredients like Tamerind, oregano oil, raw apple cider vinegar and cacao but I think i may be lacking in iron, B-12 and vitamin C. I am eating lots of fruits and veggies but apart from eating more leafy greens should I just take vitamin B-12 and C supplements to aid with this?

David December 11, 2016 at 9:17 pm

I was a strict vegetarian (though not vegan) for over 20 years. Then my 40’s hit, and I found I couldn’t eat a number of things anymore, including dairy. And I found myself tired all the time, with waning energy. I tried fish, then meat, and it did help – my energy came back. But I never felt comfortable with it,and after a year or so, I dropped the meat and am now a pescatarian. But lately I’m feeling the lack of energy again, as well as being exhausted all the time. I really don’t want to go back to meat, but we have 6 month old twins, and I’m in my mid-40’s. I need the energy to take care of them. But I hate the idea of going back. Any suggestions?

Jason December 13, 2016 at 5:17 pm

David, I’ve got two young kids so I’m not trying to make the obvious joke here, but having six month old twins and being exhausted all the time doesn’t sound like a diet problem, from my experience 🙂

Seeing a doctor would be my top recommendation, but if you want to self-experiment, drop all alcohol entirely, drop caffeine (or at least switch to green tea) at least temporarily so your body can have a chance to signal properly if it’s tired, try (try!) for that elusive 8 hours of sleep, lift some weights, and not to be all “carbs are evil” but try swapping some out for some protein and greens – as an active vegan I try for around 150g per day, eating mostly the same stuff every day, and it doesn’t take long on that regimen to notice the difference on days where I just eat whatever the kids are having (or are refusing to eat, more often…)

I don’t have anything near a complete picture of your situation, so the above is just some of what’s worked for me. Also, consider that the meat and fish may have helped, but it’s also possible that they simply displaced other foods that were making you tired. Hope that helps!

jason r February 8, 2017 at 2:55 pm

the emoji had me laughing iam a miss guided vegan going off straight will power but heyyy iam learning for the animals its not right

Alexis March 3, 2017 at 5:39 pm

I have been vegan for six weeks and feel really sluggish. Not using cooking oils, little salt, dairy or meat. I turned 70 recently and have been a meat eater my entire life. I need energy to live and while I am tempted to have a steak, I am going to give it more time.

A March 16, 2017 at 4:12 pm

Hi, I have been vegetarian for around 10 years, I tried to be ubervegan (whole foods, checking every ingredient, obsessing) in the summer of 2016, but I began loosing weight and energy. I am naturally very slim, and was relying heavily on dairy for my added calories because I don’t like greasy or processed foods. My vice was baked goods and cheese everything. I went back to being vegetarian a few months later. I started in February again trying to be vegan but this time I was determined to make it work. I have been using an app to track my food, exercising regularly to encourage my appetite, eating calorie dense foods as often as possible, doubling my portion sizes, eating health snacks as much as possible (which is hard when you have a 9-5 job)…It has been about four weeks and I am feeling lethargic despite doing everything that I have read should help me gain weight in a healthy way and boost energy…any more advice?

Jason March 17, 2017 at 7:44 am

When you say calorie-dense foods, can you give me a few examples of what you’re having?

Lana March 30, 2017 at 4:28 pm

Food intolerances make you feel tired and lethargic. I had a test done and found out that I am intolerant to nuts, beans and also some vegetables. Many people are intolerant to soya and nuts. By avoiding them foods I regained my energy levels. I also take B12 supplement every day.

Hannah April 29, 2017 at 9:00 am

Hey there,

Been vegan for 4 months. Before that i was a clean food paleo eater, only organic. I havent eaten grains or starch for many many years. I have always been a lover of high intensity exercising. I was Diagnosed after 2 months with anemia and had an iron transfusion 3 weeks ago. My tiredness seems to be here to stay. I am sleeping over 9 hrs and then needing a nap in the day. Usually i cant sleep when suns up as i have too much energy to burn. Ive never ever had this low energy and ive raised two babies on my own. Im tired and foggy. Ive been following Dr Gregers app ‘daily dozen ‘ which tells me exactly how much to eat and what food every day for the past week and im not noticing much improvement. I miss exercising. I miss my tons of bubbly energy. I wont go back but im desperate for a solution so i can be myself and my much needed mumma energy again. Oh and im taking a multi and b activate plus a super high dose of vit c every day. I dont do any processed foods. What do u do if its grains or beans that youre intollerant to?

Orestes May 25, 2017 at 12:03 am

I hear a lot of the same problems, and although I seem to feel fine, I’m still trying to solve the mystery of what exactly was the problem. I had low energy especially when I wanted to do physical work, and the only time I seemed to be energetic was when the night before I totally broke the diet. I also seemed to be very vulnerable to the cold and my knees would seemed to feel stiff frequently. I would eat and eat and never feel particularly satisfied. I did follow the low-fat route per John McDougall, but interestingly I did not eat flax seeds at the time. My diet at time was high in legumes, corn tortillas, and wheat breads, and basic vegetables. In hindsight, I think I lacked B12, Iodine, and essential fatty acid, particularly omega-3. B12 deficiency is serious but I think it takes a while to develop. Iodine deficiency too, plus if one is eating Iodized salt, deficiency should take longer. I can only guess that the only short-term consequence of a low-fat wholefood plant-based diet that could cause nearly immediate weakness is essential fatty deficiency. Since almost last year, I started taking ground flax seeds, and I feel much better. Within a couple days, my knees felt fluid again.

Stacey E. July 14, 2017 at 2:16 pm

The problem with loading up if you’re losing weight is that I’m switching to this diet (initially) just for that purpose. So to try cramming in more food to defeat weight loss that I’m trying to achieve is a problem. I am a vegetarian that’s gradually switching over, I have 40 pounds to lose, and I’m still as tired as I was before. The only difference is that now I wake up much earlier, and I am actually more energetic than I was. So to still feel tired, from the sinus’ up, is weird. I’ve been battling sinus infections for several years so maybe that’s the problem. I assume being overweight is causing apnea, but I would expect my whole body would feel tired if that’s the reason, not just my head from the nose up. Maybe the fresh juice enzymes are working on my sinuses. I hope so. I think the problem with most of the people here talking about dizziness and real weakness are because they’re semi-starving themselves. You’re supposed to still eat. I know a lot of people are promoting fasts, but the only thing that really does for you is starve you. Unless it’s for religious reasons, you’re wasting your time. You end up eating your own muscle tissue when you magically lose weight on fasts. Because your body wants to eat something, and when you starve it, it eats you. Sorry kids.

C.S.M. October 13, 2017 at 8:24 am

Thank You to everyone who submitted information about being a vegan. I have been a vegan since 8/13/2017 and today is 10/13/2017. It has had it’s challenges and benefits. The first two weeks i felt like crap and had a headache everyday. Then i felt great for a few weeks and then the cravings started which was a struggle but i made it through. Now i am just exhausted everyday even though i get 8 hours of sleep. I wake up feeling great and then the energy just leaves my body. I take B-12 and a multi-vitamin but i may not be eating enough. I try to be conscious about getting enough protein but i may not be eating enough food. i eat breakfast between 6:30 and 8:30 am and may not eat again until 3 or 4 pm. I really hope this works because this is not a good feeling especially at work.

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