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new vegan, headaches, weak and shaky

Hi all

I'm a new vegan. Loving the food, but having terrible headaches, shakes, weak and tired.  The problem is, I am an amateur triathlete and it is greatly affecting my training schedule. Is this just my body adjusting to the change and it will get better or am I doing something wrong.  :-\

I was originally inspired to become a vegan by Scott Jurek who is a ultra runner, so I KNOW it can compliment a heavy training schedule.

An example day is -
breakfast - granola, fruit and soya milk. Green tea, apple juice with with Dr Udo's 'beyond greens' supplement.
Lunch - Falafels, houmous, olives, salad and pitta, apple juice with Dr Udo...
Dinner - Tofu thai red curry with Quinoa, millet and brown rice medley, green tea, water.
snacks, rice cakes with marmite or houmous, nuts, dried fruit.

Thanks for your help.  :)>>>

I think your body is detoxing all the old animal fats and extraneous stuff from eating meat and dairy.  It's probably a good thing.  Drinking lots of water, and getting as much rest as you can is usually recommended.  Green drinks can be super cleansing.  Try using a little less for now and slowly increase.  You'll be feeling powerful in no time!  Good Luck might enjoy this site


If you are concerned that your symptoms are a result of not meeting your nutritional needs, you can see a dietitian about it. You can also log everything you eat on a website like or, and see how you fare on every nutrient each day (on the mypyramid one, you can also track calories burned, but it's a bit tiresome entering that data).
I think it depends on what you were eating before going vegan. I have known some people who felt ill for a little while when they not only went vegan cold turkey, but suddenly eating healthy, lots of vegetables, etc from a diet heavy in animal products; any sudden dietary change can upset things. Also, if you were nearly vegan before (maybe had dairy now and then), it really might not be the lack of animal stuff, but a long term problem or just a calorie deficiency. Again, you can tract your nutritional intake to see.

Personally I didn't really have much of a shift when I went vegan in any sense, but at the time I was pretty lazy, so... yeah.


I had a stubborn headache for the first few days of going veg. Then it just dissapeared and I was on a super natural high.  :D
As willowbeez said, I think it's just a detox type of thing. The body needs to adjust to the change.
But if the weakness goes for too long, it might mean you're lacking something.

Oh, and congrats for going vegan! Your body and the earth will benefit.  ;)b


If you continue to feel weak/shaky, you might not be eating enough for the training that you do. You might just need more calories!


If you continue to feel weak/shaky, you might not be eating enough for the training that you do. You might just need more calories!

That's what I was thinking.  I know my body feels the best when I eat a lot greens.  I'm addicted to kale and collards.  They are so nutrient dense and you can eat them so many different ways.  You could also add some healthy smoothies to your diet.  I like to add kale, ground flax, and wheat bran to fruit smoothies.  My bf (Camillus) also likes to add spirulina.  Here's an example of his smoothie, but obviously you can add anything.  Congratulations on becoming vegan!  Vegweb is a great resource.


Thank you all for your comments. The headaches and shakes etc are already subsiding and I am starting to feel great. Still a way to go, but something has definitely changed.
The training is getting back in track (which is great because I'm competing in the London triathlon this weekend!) I'll keep you posted on my progress.



Could be detoxing, as mentioned by others, or a deficiency (likely iron, but don't supplement for this without a Dr.'s say-so). I don't know what your training schedule is like or the intensity, but when I was an elite athlete I needed to consume roughly 3000 calories a day (that was at a weight of 100lbs). As a healthy plant based diet isn't calorically (sp?)dense I ate constantly. Your food choices look good but there's no indication of how much you're eating.

Take a good look at what nutrients you might be lacking, how frequently you're eating (it should be every 1.5 - 3 hours), how many calories you're consuming and how many you're expending.

Good luck & take care.


Great news, I'm feeling fantastic at last!!!

I originally gave myself a 30 day trial period on the vegan diet. I didn't see the point in being veggie first, my opinion is if you're going to do it.... do it!!! Well, I'm hooked! I have added some vitamins to the daily regime, spirulina, barley grass, vitamin D and aloe vera juice with a fresh made veggie juice and I am picking more between meals on things like nuts, seeds and fruit. I've never felt better.

Competed in the London triathlon at the weekend and knocked 14 minutes off of my last race - wonderful!! I was struggling on the run and imagined Scott Jurek running next to me - kept me going!!


Maybe one dish wasn't agreeing with you very well.

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