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Life Sciences => Physiology & Medicine => Topic started by: Martin on 12/06/2008 08:09:09

Title: Why do I have less energy now that I'm vegan?
Post by: Martin on 12/06/2008 08:09:09
Martin asked the Naked Scientists:

I have wondered why I have less energy now that I'm vegan.

Obviously with the change to my diet I'm taking in way more carbs and things like potatoes are way more energy efficient than something like a steak?  Could the energy drop be due to the lack of fats that I'd be getting from things like cheese?

What do you think?
Title: Why do I have less energy now that I'm vegan?
Post by: Karen W. on 12/06/2008 08:22:20
I think it may be the protein... and the iron rich foods.. you need to make sure you eat things like raisens beans etc... I get tired too when I cut out my meats etc.. so you really need to learn to balance the right amount of substitute proteins and iron rich food to help your blood and support muscle building as well.. now I am no expert but have worked with many vegan children in a preschool setting and it is not easy to learn to get the balance right... Good luck to you and welcome to the site Martin and thanks for the great question!
Title: Why do I have less energy now that I'm vegan?
Post by: neilep on 12/06/2008 12:36:26
Yep...great question Martin.....as Karen says, the first thing I though was the lack of protein.....like it or not humans are carnivores and so if you're going to stop eating anything animal related completely then you need to make up for what your body needs. In any case, unless you have some kind of lethargic virus it simply must be you change of diet.

As a vegan I guess this means you don't drink milk either eh ?....I for one would like to know the dietry protocols of being a vegan.......ok...you're just gonna have to join up to answer that aren't you ?  [;)]
Title: Why do I have less energy now that I'm vegan?
Post by: iko on 13/06/2008 11:48:00
Hi Martin,

'vegan' diets may be harmful when unproperly followed...and maybe they could be harmful for certain individuals who carry invisible metabolic defects.
If somebody is perfectly fit on a certain diet, that doesn't mean that anybody would get the same result.
Be careful and follow experienced advice (I'm not your expert, I'm afraid!).
Take care

ikod



do we actually need vitamin suppliments? you see in boots for instance, a whole range of suppliments with a lot aimed at children.

do children need suppliments?

I can see a case for them in more deprived countries where a balanced diet may not be possible.

Hi paul.fr,

It is just a matter of knowledge, culture, information or family tradition if you like.
We may not be what we eat, but certainly we have to eat to survive, even if we tend not to live only to eat, fortunately.
If the combination of foodstuff we eat from time to time is correct, thanks to our family traditions and culture, for example, we probably won't have any deficiency problem from the cradle to the end of our life.  Even if we have to face a period of starvation or a polar expedition, our information, culture, tradition will help.
Over the years, many children had to be reminded: have your orange juice plus scrambled eggs, get your fresh veggies each meal, eat fruits, drink your milk and go play outside, take your 'cod'...
Ignoring the basic priciples of our survival on this Planet might lead to dreadful consequences.
At least one young man became irreversibly blind for a badly managed diet.
Here is the story:

Blindness in a Strict Vegan

Vegetarians are at risk for nutritional deficiency if they do not receive vitamin supplementation. We report a case of severe bilateral optic neuropathy in a patient who had been a vegan for many years and who did not take vitamin supplements.
The patient, a 33-year-old man who had started a strict vegetarian diet at the age of 20 years, was referred for evaluation of progressive visual loss. "Improved health" was the reason for the diet, which contained no eggs, dairy products, fish, or other sources of animal proteins. He did not smoke or use alcohol, and his medical history was unremarkable.

Examination showed severe bilateral optic neuropathy with very poor vision (less than 20/400 in both eyes), central scotomata, dyschromatopsia, and atrophy of the optic disks. We found no evidence of a compression of the visual pathway or of a toxic, infectious, or inflammatory cause of the blindness. Mitochondrial-DNA analysis showed no mutation for Leber's hereditary optic neuropathy. On neurologic examination, there was a sensory peripheral neuropathy, confirmed by electrophysiologic studies. The cerebrospinal fluid was normal, including the opening pressure. The remainder of the general examination showed no abnormalities.

The plasma level of folate was low (5.4 nmol per liter; normal range, 7.5 to 28), as were the levels of vitamin B1 (4 nmol per liter; normal range, 6 to 40) and vitamin B12 (114 pmol per liter; normal range, 150 to 720). There were also deficiencies of vitamins A, C, D, and E and zinc and selenium, but plasma levels of iron, ferritin, vitamin B6, and nicotinamide were normal. The patient had megaloblastic anemia (hemoglobin level, 10.5 g per liter; mean corpuscular volume, 110 µm3), which was not due to pernicious anemia (there were no anti–parietal-cell or anti–intrinsic-factor antibodies, upper gastrointestinal endoscopy showed normal findings, and multiple biopsies showed no gastric atrophy) or other causes of malabsorption. After treatment with intramuscular vitamin B12 (1000 µg daily for one week) and oral multivitamin supplementation, the hemoglobin level was normal and the sensory neuropathy had disappeared, but there was no recovery of vision.

Vitamin B12 deficiency in vegetarians may cause neurologic disturbances.  Moreover, deficiencies of vitamins B12 and B1 may be responsible for optic neuropathy associated with nutritional factors.   Amblyopia and painful neuropathy have been reported in cases of dietary deprivation in prisoners during World War II, and more recently, dietary factors were noted in the Cuban epidemic of optic neuropathy.4 The optic neuropathy in our patient was apparently related to deficiencies of vitamins B12 and B1, but other associated deficiencies may have had a role. Vitamin supplementation is essential in persons who adhere to a strict vegetarian diet, especially because vitamin deficiencies may cause severe, irreversible optic neuropathy.


Dan Milea, M.D.
Nathalie Cassoux, M.D.
Phuc LeHoang, M.D., Ph.D.
Groupe Hospitalier Pitié–Salpêtrière
75651 Paris CEDEX 13, France

New England Journal of Medicine  342:897-898  March 23, 2000.

Title: Why do I have less energy now that I'm vegan?
Post by: Martin on 13/06/2008 12:24:28
hey everyone thank you for your replies.

there are a few points that are important to this:-  my diet is actually very protein rich because I have a lot of nuts, beans and soya.  Also I've pretty sure that you don't get energy from protein but you do from carbohydrates no matter how complex fat down the the most simple sugars.

When people say human are carnivores is nonsense!  Carnivores have long k9 teeth, ours are short.  We get very ill if we eat raw meat.  we can't move very fast, we don't have claws infact without weapons we can't hunt.

There are a number of arguments against being vegan but they are all just lack of information.  this is why I would never argue with anyone on this matter but if they would like facts I'm happy to share.

I was glad to see that someone mentioned vitamins.  As TV adverts point out our body are very smart when it comes to this and as long as there is enough of the right ones in our diet our bodies can sort the rest.  As highlighted in the quote vit b12 and i think it's 6 mostly comes from beef which is why i take supplements as most vegans do.

I know that most dietions recommend a mostly vegan diet because red meat is bad for you and most fats and all cholesterol comes from meat and dairy.

something i thought it could be is that because i no longer have a layer of meat sitting in my stomach rotting rather than being digested is the whole system going too quick and I'm not getting everything out of what i do eat?
Title: Why do I have less energy now that I'm vegan?
Post by: neilep on 13/06/2008 13:24:01
WELCOME MARTIN !!!... [:)]


As far as I know being carnivorous just means that one eats meat.....it does not imply that it is prerequisite for the carnivore to eat meat !!...that's all what I meant !...I was not being confrontational at all !


I notice you say that most dietitians recommend mostly a vegan diet !..then, when they say " mostly"  this must mean not 100%.....I too have been told the same as you but it has been mentioned to me to cut it down.....to maybe one or two portions a week....not desist eating it completely......that has been the advice given to me.


What about fish Martin ?...does the same apply ?...just asking ok ?...not baiting for an argument !

Anyway....I welcome you as a member and hope that you stay around to investigate the rest of the site.

I'm still very interested to know about the vegan diet.....can you help me in this regard ?....I'd really appreciate to know the foods that are complete no-no's

Thanks Martin. [:)]
Title: Why do I have less energy now that I'm vegan?
Post by: RD on 13/06/2008 13:54:16
like it or not humans are carnivores

Surely humans are omnivores ?.
http://en.wikipedia.org/wiki/Omnivore
Title: Why do I have less energy now that I'm vegan?
Post by: RD on 13/06/2008 14:36:46
I know that most dietions recommend a mostly vegan diet because red meat is bad for you and most fats and all cholesterol comes from meat and dairy.

If "all cholesterol comes from meat and dairy" then how does cholesterol get into beef and milk, despite cows being veggie ?.

If you have a child will you refuse it mother's milk as it is an animal product ?.

You're on a losing wicket if you're arguing for veganism from a health reasons:
the title of this thread and your use of "supplements" are evidence of this.

PS
 
Quote
We get very ill if we eat raw meat.
sushi and horse are examples of flesh eaten raw with no ill effects provided they are fresh.
Title: Why do I have less energy now that I'm vegan?
Post by: Karen W. on 14/06/2008 08:16:26
Horse?????
Title: Why do I have less energy now that I'm vegan?
Post by: RD on 14/06/2008 09:15:06
Horse?????

Quote
Besides being served raw, it can be broiled for a short period, producing a crusty exterior and a raw, moist interior.
Smoked horse meat is very popular as breakfast and sandwich meat.
http://en.wikipedia.org/wiki/Horse_meat

Personally I like my steak well done, but horse is a meat I had heard was served raw.

The only side-effect of eating horse meat is that you feel like jumping over a fence afterwards  [:)]
Title: Why do I have less energy now that I'm vegan?
Post by: neilep on 14/06/2008 13:43:48
For a long time here on this site I asked the question if a vegetarian/vegan would eat a venus fly trap salad ? (let's assume they taste delicious etc etc)...and other carnivorous plants ? I've asked twice so far......

Perhaps asking here will afford me a third time lucky !

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Title: Why do I have less energy now that I'm vegan?
Post by: Bored chemist on 14/06/2008 21:30:32
A few points.
First It's very difficult to find an adequate source of vitamin B12 in a vegan diet (IIRC yeast is good, but check that)
Second your body is quite capable of producing cholesterol for itself. This is just as well because, while rasied levels are sometimes associated with poor health, the absense of cholesterol would kill you imediately.
Title: Why do I have less energy now that I'm vegan?
Post by: grumpy old mare on 15/06/2008 13:04:50
Raised cholesterol is, to my knowledge, to a large extent due to ones genetic make-up (I mean a tendency to high (too high) cholesterol levels is an inherited "defect") and has much much less to do with diet than producers of certain oh so good foods and medication would want us to believe.

Quote
We get very ill if we eat raw meat.

Who says that? That's not "a fact of life"!!
It is very normal in traditional German, Italian, Spanish.... diets to eat raw meats, mainly beef and pork. Yes, pork from unchecked sources MAY contain contain a bacterium that causes aujetzky, but then you can get really ill eating vegetables that are not quite ok.

And no, I'm not trying to be confrontational either, but I'd prefer facts.

Quote
I have wondered why I have less energy now that I'm vegan.

Obviously with the change to my diet I'm taking in way more carbs and things like potatoes are way more energy efficient than something like a steak?  Could the energy drop be due to the lack of fats that I'd be getting from things like cheese?

To go back to your first question - I would suggest it's because of a lack of fats! But I think it may get better if you can increase the intake of vegetable fats of different sources, e.g. change between linseed oil, sunflower oil, olive oil....
Title: Why do I have less energy now that I'm vegan?
Post by: Martin on 20/06/2008 13:52:27
hopefully this time my PC wont crash as it has the past 3 times I've tried to write this!

yup i was totally wrong when i said raw meat will make you ill!  What i was getting at is that true carnivores have a longer digestive system which means that you can eat rancid meat and it smells nice to them.

I'm actually really interested in the fact that our body haven't adjusted to eating meat.  historically man started eating meat because there was little alternative.  presumably starting as scavengers then moving to doing things like tricking animals into falling off cliffs then on to hunting.  fire came a long time before hunting and tools so may scavenging and cooking also did?  this is a very odd time in human history and the fact are always being updated as we develop ways to investigate history.

as a vegan I don't object to eating meat it's the farming methods - england is a lot better than America for instance but still horrific!  there are also extremely strong environmental arguments for being vegan.  The amount of energy and land required to create beef is significantly greater (thus less efficient) than to product plants.  Remember the animals have to eat something too!

people often argue that it doesn't hurt chickens to lay eggs... ask any woman I'm sure they wouldn't like to have been bread to have as many periods as possible!  chickens it is mostly about the conditions they are kept in howevery most males that are born are destroyed.  People argue that milking doesn't hurt - it's extremely stressful and they have to be kept in calf so they keep producing milk and again the calf's are often destroyed in the field.  this is why vegans don't eat eggs and milk.

I don't object to people eating meat and eggs or drinking milk but it's better for our plannet if we didn't.

Venus fly trap salad? that's pretty good! I'd object because it prob wouldn't taste fantastic! I don't know how all vegans feel but the way i see it humans don't need to be cruel and have the ability to avoid cruelty so they should.

thank you for the answer to my question - sorry can't remember who said it tho!!! think that's the most likely cause isn't it.  I actually posed the question quite a while ago and since have found my energy leaves are a lot more consistent now.  I'm guessing it took a while for my body to adjust to plant fats instead?

the people who want to know more about a vegan diet try the vegan society web site http://www.vegansociety.com/home.php

Title: Why do I have less energy now that I'm vegan?
Post by: Karen W. on 20/06/2008 14:11:11
Martin asked the Naked Scientists:

I have wondered why I have less energy now that I'm vegan.

Obviously with the change to my diet I'm taking in way more carbs and things like potatoes are way more energy efficient than something like a steak?  Could the energy drop be due to the lack of fats that I'd be getting from things like cheese?

What do you think?

I did say Iron or proteins you don't have to have meat to build iron.

Lack of iron leads to anemia and low energy and just feeling tired.. I believe raisins Broccoli and such iron filled goodness will eliminate that tired no energy feeling.  Fats are usually some of the ways most carnivores supplement their proteins to get the desired iron.. but other vegetables can do that well if you seek out the iron rich foods!

heres a list:  http://www.ivu.org/faq/vitamins-minerals.html

 Should I worry about iron on a vegetarian/vegan diet?

To quote Vegetarian Times (August 1992, p. 60):

"Iron deficiency, unlike protein deficiency, sometimes is a real problem, but meat is not the answer. The American Dietetic Association said in 1988 that vegetarians don't have a higher incidence of iron deficiency than nonvegetarians.

If you are concerned about getting enough iron, avoid eating iron-rich foods along with substances that inhibit iron absorption: phyates (found in high-bran and unmilled cereals), polyphenols (such as tannins in tea) and calcium. Eat iron-rich foods along with foods containing vitamin C, which aids absorption. Good sources of iron include dried figs and prunes, dark-green leafy greens, legumes, certain whole grains such as quinoa and millet, blackstrap molasses, nuts and nutritional yeast. Acidic foods cooked in cast-iron pans are also good sources of the mineral."

How long should I wait between drinking tea and eating iron enriched foods?

from a member of ivu-sci:
I recall a lecture some years ago in which the speaker (a nutrition expert from Oxford Brookes University) recommended that vegetarians avoid drinking tea within one hour either side of a meal.
How strict one should be about this clearly depends on other factors such as the strength of the tea and total non-haem iron intake. (Non-haem iron is the sort available to veg*ns, the other sort is haem iron which is found only in meat and fish.)

Vitamin C enhances non-haem iron absorption, whilst phytate and polyphenols (including tannin found in tea and other beverages such as coffee and red wine) are major inhibitors of non-haem iron absorption. Thus, the iron absorbed from a meal containing non-haem iron may be doubled if the meal is taken with a glass of orange juice or reduced to one-third if taken with tea.

Reference:
Chapter 9 (Iron) of Essentials of Human Nutrition
Jim Mann & A Stewart Truswell (eds)
Oxford University Press, 1998.

Are there any supplements I could take to increase the amount of iron in my body?

from the UK:
I find that Superdrugs own brand of Multivitamins plus Iron is really good. As well as providing 100% RDA of iron, it also provides Vitamins A, D, E, C, B1, B2, B6, B12, Niacin, Folic Acid, Biotin and Pantothenic Acid. It's only around £3.00 for 120 1-a-day tablets.

Which vegetables are rich in iron?

from members of ivu-sci::
Dried fruits, wholegrains (including wholemeal bread), nuts, green leafy vegetables, seeds and pulses (chickpeas, baked beans, lentils etc.)are rich sources of iron.
These foods are generally consumed in reasonable quantities so can provide a good proportion of daily iron requirements. Also of relevance are parsley, watercress, edible seaweeds and black molasses, although none of these are usually consumed in large quantities.
Iron is absorbed less well from plant based foods than from meat, as it is in the non-haem form, but it's absorption is improved by the presence of Vitamin C, malic acid and citric acid. Good Vitamin C sources are green leafy vegetables (including cauliflower), citrus fruits, mangoes, tomatoes and potatoes. Citrus fruit is also a source of citric acid, whilst malic acid is found in apples, plums and pumpkins (amongst other foods). Phytates (such as in nuts, grains and seeds) can reduce iron absorption, as can tannins (from tea). Generally, because of the high dietary intake of iron rich foods in a balanced vegan diet, these two negative factors are not usually a problem but iron deficiency can occur as a result of heavy menstruation.

Vegan Nutrition (Gill Langley, The Vegan Society, 1995) lists "dried fruits, whole grains (including wholemeal bread), nuts, green leafy vegetables, seeds and pulses" as rich plant food sources of iron. The absorption of iron is enhanced by the presence in the same meal of vitamin C (plentiful in fruits and vegetables), but can be reduced by tannins (from tea) and phytates (from nuts, grains and seeds). The use of iron cookware can also increase iron intake.

Further information on Iron:

    * Iron (VegSocUK)
    * www.vegetarian.org.uk/factsheets/ironfactsheet.pdf
Title: Why do I have less energy now that I'm vegan?
Post by: grumpy old mare on 20/06/2008 19:23:21
Quote
What i was getting at is that true carnivores have a longer digestive system which means that you can eat rancid meat and it smells nice to them.

True - that's why we're at least supposedly 'omnivores'. Just like dogs, who also don't HAVE to have meat to survive, but meat is .. hmm... I don't know the scientifics, but I think meat is more 'energy efficient' for our bodies and that of dogs. (cats are carnivores)

By the way - the Panda is a Carnivore (i.e. all physical 'signs' of a carnivore, from teeth to digestive system) that ONLY eats veg (if bamboo can be called 'vegetable'?). Strange nature ...

Quote
historically man started eating meat because there was little alternative.

Do you (and historians) mean that at very first there was enough alternative or how can I understand that paragraph? (Again - I'm really not trying to be controversial, I'd really like to know and my prejudice is that a vegan website (just like a "we're meat eaters"-website) might be a bit biased  [;)])

Quote
as a vegan I don't object to eating meat it's the farming methods


THAT argument I can fully understand!  [:)] We're trying to become more and more self-sufficient because of a lot of the reasons you state in this and following paragraphs!

Personally, I find purely vegan still quite dangerous. Probably because 2 of the 3 'true' vegans that I know have something like "total burn out syndrome", even though I don't know if that has anything at all to do with them being vegans or if it's "only" because they worked a long time very very very hard in animal rescue!


Title: Why do I have less energy now that I'm vegan?
Post by: Martin on 22/06/2008 11:01:53
I didn't know that about pandas! that's really interesting!

efficency of eating meat is actually very very low for example it can be proven that it's better for the environment to drive to the shop than walk if you only eat beef!  generally energy comes from carbohydrates - which are sugars, starch, alcohol and fat - sure there's more.  I believe what someone told us earlier is that it's possible a lack of iron.  not sure able levels but i'm heard that brocoli is among the best places to get this however it's distroyed by cooling and if it's someone quick to make it's gunna be cooked really harshly - I expect your friend have my problem of not making enough time to get the right things.  meat eaters get this too - i know this all too well cos i was just as bad as one ;)

eating meat meant that man could populate places that our ancestors couldn't without physically changing that much hence progressing so fast.  So we could have lived much as the apes did but i massively smaller numbers.  basically the forests of the planet declined really dramatically and hundreds of spicies died out it was because we chose to stand on 2 legs and eat other things and use tools that we got past that bit...