# What factors affect height? **URL:** \ **Category:** Factual Questions\ **Created:** [August 25, 2011, 1:30pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032 "2011-08-25T13:30:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![anon11](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@anon11](https://boards.straightdope.com/u/anon11)\ **Post date:** [August 25, 2011, 1:30pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/1 "2011-08-25T13:30:02Z")
I am 6 ft 3. This is three inches bigger then any relatives. I am a lifelong vegetarian. I was fairly active when I was young and well fed. Why am I taller then my family? I have read about growth hormones in meat, perhaps these hinder growth. I feel I am “stretched out” and have grew taller then expected. I am in my twenties, so I should have stopped now. ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [August 25, 2011, 1:32pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/2 "2011-08-25T13:32:42Z")
How tall were your grandparents and great grandparents? ---
**Author:** ![Annie-Xmas](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@Annie-Xmas](https://boards.straightdope.com/u/Annie-Xmas)\ **Post date:** [August 25, 2011, 1:34pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/3 "2011-08-25T13:34:52Z")
Genetics and nutrition. People are taller today cause they were fed better as children. ---
**Author:** ![anon11](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@anon11](https://boards.straightdope.com/u/anon11)\ **Post date:** [August 25, 2011, 1:36pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/4 "2011-08-25T13:36:39Z")
I don’t know about great grandparents or all of my grandparents. They are all average five foot something. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 25, 2011, 2:01pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/5 "2011-08-25T14:01:38Z")
Well we do not know your gender or your parents actual heights, so we are a bit limited in a specific response. What we can say is that the _average_ child of a mating is likely to be near the “mean parental height”, which for males is: (Mom’s height + 5 inches plus Dad’s height)/2. For females it’s Dad’s height - 5 inches plus Mom’s height)/2 The farther off the two parents heights are after the 5 inch correction the greater the spread around that average you can reasonably expect a child to grow to. Also the more variety in the extended family (some stealth genes from grandparents for example). And of course average is just average; any particular individual can be an outlier. Being just 3 inches taller than your Mom for example is actually being shorter than her male equivalent, who is 2 inches taller than you. Gender matters here. The United States and most of Western Europe saw an [average rise in height for multiple generations](http://www.sciencedirect.com/science/article/pii/S1570677X02000333) as a result of improvements in basic childhood nutrition and healthcare; this rise has not been observed in the last few generations however. It is unlikely that being a vegetarian has resulted in any significant increase in height. At least [in women](http://www.ncbi.nlm.nih.gov/pubmed/16277803) there is no difference found in end height based on being a lifelong vegetarian. Some studies however have show a possible height advantage, like 1/2 to 2 cm, _associated with_ a vegetarian diet through childhood. (See [here](http://www.nature.com/?file=/ejcn/journal/v51/n1/abs/1600354a.html) and [here](http://www.ncbi.nlm.nih.gov/pubmed/1855500).) FWIW. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [August 25, 2011, 2:03pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/6 "2011-08-25T14:03:34Z")
How tall are your father and mother? One way to predict the most likely adult height for a child is to average the height of their parents, then subtract 2.7" for a girl or add 2.7" inches for a boy. If, for instance, your father and mother are both six foot tall, that would mean (assuming that you’re male) that your most likely expected height would be 6’2.7". That’s only the most likely expected height though, and it wouldn’t be hugely improbable for a child to be as much as six inches off from that most likely expected height. ---
**Author:** ![anon11](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@anon11](https://boards.straightdope.com/u/anon11)\ **Post date:** [August 25, 2011, 2:44pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/7 "2011-08-25T14:44:42Z")
My mum is 5ft 9 and my dad is 5ft 10. ---
**Author:** ![anon11](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@anon11](https://boards.straightdope.com/u/anon11)\ **Post date:** [August 25, 2011, 2:48pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/8 "2011-08-25T14:48:09Z")
Also, is the improved nutrition in part due to fortified foods? When did foods start being fortified? ---
**Author:** ![rhubarbarin](https://avatars.discourse-cdn.com/v4/letter/r/eb9ed0/32.png) [@rhubarbarin](https://boards.straightdope.com/u/rhubarbarin)\ **Post date:** [August 25, 2011, 2:57pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/9 "2011-08-25T14:57:55Z")
Genetics, nutrition, stress on the growing body. And most especially, nutrition and stress during the major ‘growth spurt’ ages 11-14 or so, when the femurs do most of their growing. Leg length is the main factor in the height differences across populations and history - things like heavy labor, malnutrition, and childbearing in the early teens years are going to depress long bone growth and height a ton. Genetics can be awfully unpredictable when it comes to height. My mom is a shorter lady (5’3"), my dad is 6’1". I followed the usual rule (I am 5’5" on the dot), but my sisters ended up 5’10" and 5’2". It’s worth noting my mom is from a taller family (everyone is on the taller side, and of her mom and 4 sisters, none is shorter than 5’6"), which explains my tall sister, but not the unusual shortness of my mom and short sister. Also I had eating problems (along with severe emotional issues) which were severe enough to lead to ‘failure to thrive’ as a kid; and yet it didn’t seem to depress my height significantly, and I even have longer legs for my height. Maybe if I had been a healthier child I would be much taller, who knows. ---
**Author:** ![anon11](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@anon11](https://boards.straightdope.com/u/anon11)\ **Post date:** [August 25, 2011, 3:44pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/10 "2011-08-25T15:44:53Z")
What about exercise? Does that play a role? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 25, 2011, 8:32pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/11 "2011-08-25T20:32:17Z")
> [@anon11](#): > > My mum is 5ft 9 and my dad is 5ft 10. Going over to the growth charts your mother is about 98%ile height for women. A male that percentile is about 6 foot 3 inches. You really are consistent with height on your mother’s side. No exercise is not much of a factor. And the health/nutritional effect on femur growth is actually very early in life. Don’t know about the answer re food fortification. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [August 25, 2011, 8:46pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/12 "2011-08-25T20:46:35Z")
Obviously there’s a huge genetic component, but some of it may be dominant & recessive as well as sex-linked. There also may be mutations involved. According to the “average your parents’ heights and add 5 inches” for boys, I should be 5’7". Instead, both my brother and I are much closer to our father’s height (6’3") at 6’1" each. My wife’s mother is fairly tall- like 5’10" and her dad is about the same height. Yet my wife’s 6’2", and her sister is only like 5’7". Our big question is whether our son will end up closer to my height, or if he’ll stick to the average + 5 formula, which will make him at least 6’4". ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [August 25, 2011, 9:35pm UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/13 "2011-08-25T21:35:53Z")
My mother was about 5’5" and my father 5’10". I am 6’1". But, and this is an important but, my father grew without enough to eat. In fact, his legs were bowed and we think that was evidence of malnutrition. There could have been other factors. Here is another possibility. This is a real anecdote. My mother’s best friend when she was growing up. Her parents were about 5’ and 5’6" (I never knew the mother, but the father taught in my HS and I did know him. The BF was over 6’. Moreover, she had a man’s voice. She said that ordering bras over the phone was a real trip. She was quite a handsome woman, married a man who was about 6’6". They had a daughter who was maybe 5’7". She married a man of modest height (under 6’, I would guess) and they had a daughter who was maybe 5’6". You can see that the woman was some sort of exception. Can you say “acromegaly”? Anyway, I read somewhere that geneticists estimate that there at least 100 genes that contribute to height. So two relatively short people can easily have a tall offspring. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 26, 2011, 1:10am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/14 "2011-08-26T01:10:09Z")
Again, the mean parental height tool is about predicting _averages_. And a wide variation in parental percentiles predicts a greater variation about the mean among the children … on average. I tend to use it as saying that the likely range is between Mom and Dad’s percentiles, on average in the middle. Not written in stone. ---
**Author:** ![isaiahrobinson](https://avatars.discourse-cdn.com/v4/letter/i/85e7bf/32.png) [@isaiahrobinson](https://boards.straightdope.com/u/isaiahrobinson)\ **Post date:** [August 26, 2011, 1:19am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/15 "2011-08-26T01:19:37Z")
My impression is that for your regular child here in the West, height is pretty much 100% determined by genetics. As long as they’re well-nourished and not doing some sort of heavy labor it’s not going to make any difference whether they’re vegetarians, whether they eat fortified foods or how much sport they play. I suspect studies would bear that out. Anyone have evidence supporting or disproving my suspicion? ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [August 26, 2011, 1:56am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/16 "2011-08-26T01:56:24Z")
O.K., so your father is 5’10" and your mother is 5’9". The average of their two heights is 5’9.5". The mostly likely estimate for their male child would thus be 6’0.2". You’re 2.8" taller than that. There’s nothing surprising about the fact that you’re 6’3" then. There’s no reason to think that environment particularly affected your height at all. Purely by the luck of the draw (since genetics is about randomly grabbing some of your mother’s genes and some of your father’s genes) you got some of the taller genes. ---
**Author:** ![Lacunae\_Matata](https://avatars.discourse-cdn.com/v4/letter/l/8491ac/32.png) [@Lacunae\_Matata](https://boards.straightdope.com/u/Lacunae_Matata)\ **Post date:** [August 26, 2011, 2:23am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/17 "2011-08-26T02:23:26Z")
I know next to nothing about the science of genetics, but I know a lot about the “Heinz57” nature of families, especially given the Western Hemisphere’s wildly diverse population. Sure, just looking at my parents’ heights (5’5" & 6’,) one might predict very average heights for their kids. However, I’m 5’9", my sister was 5’1", and my brother is 6’2.5". Our grandfathers were both average/tall for their generation (6’), but one grandmother was also 6’, while the other was only 4’10". And the tall grandmother’s father was practically a giant at 6’9".\* So I’d say that overall good nutrition, plus a good dollop of genetics probably played a bigger role in your adult height than whether you eschewed steak and bacon… \*Yeah, I know anecdotes aren’t data. Just describing a situation in which genetics determined outcomes which might have surprised a casual observer. Kind of like when my two blond parents had 3 redheads - an outsider wouldn’t have looked back a generation to see the redhaired Grandma, nor the Titian titan of a great-grandfather. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 26, 2011, 4:33am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/18 "2011-08-26T04:33:00Z")
> [@isaiahrobinson](#): > > My impression is that for your regular child here in the West, height is pretty much 100% determined by genetics. As long as they’re well-nourished and not doing some sort of heavy labor it’s not going to make any difference whether they’re vegetarians, whether they eat fortified foods or how much sport they play. I suspect studies would bear that out. Anyone have evidence supporting or disproving my suspicion? See post#5. One exception is based on altered _prenatal_ environment, such as from placental insufficiency or poor prenatal nutrition leading to a child who is small for gestational age at birth (SGA). Typical middle class adequate nutrition from birth on is enough to place them at risk for obesity and they are at risk of metabolic syndrome at lower BMIs than more typically sized babies, but they will still typically end up an average of [almost 4 cm shorter](http://journals.lww.com/pedresearch/Abstract/1998/06000/Prediction_Factors_in_the_Determination_of_Final.15.aspx) as adults. 10% of those with SGA will end up below the 3%ile without intervention ([growth hormone works well](http://pediatrics.aappublications.org/content/124/3/e519.full) for the group that does not have catch up growth by age two). That said, other prenatal factors that lead one monozygotic twin to be [larger at birth](http://www.atypon-link.com/AAP/doi/abs/10.1375/twin.7.5.421) and during the first 6 months compared to its twin, may prime for later obesity risk in adolescence and young adulthood, but not for any difference in height. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [August 26, 2011, 5:43am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/19 "2011-08-26T05:43:38Z")
> [@anon11](#): > > I am 6 ft 3. This is three inches bigger then any relatives. I am a lifelong vegetarian. I was fairly active when I was young and well fed. Why am I taller then my family? Hey, you’re one of the lucky ones. I’m fully grown, and while not a bad height (6’) I’m a full two inches shorter than my dad and three inches shorter than my little brother. WTF happened? ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [August 26, 2011, 5:45am UTC](https://boards.straightdope.com/t/what-factors-affect-height/594032/20 "2011-08-26T05:45:11Z")
> [@bump](#): > > Obviously there’s a huge genetic component, but some of it may be dominant & recessive as well as sex-linked. There also may be mutations involved. > > According to the “average your parents’ heights and add 5 inches” for boys, I should be 5’7". Instead, both my brother and I are much closer to our father’s height (6’3") at 6’1" each. According to the formula for girls I should be around 5’7" too, but I’m not. Instead I’m shorter than both parents. In my case something when wrong when I was a toddler and I didn’t gain any weight or grow at all for two years (possibly celiac disease, but I still haven’t been tested) and something nutritional post-weaning is probably to blame because I was a big baby, over 8lbs and 22" at birth, but fell behind the other kids within a couple of years. Lil bro, on the other hand, at 5’11" is the height you’d expect given our parents’ heights. [Next page](https://boards.straightdope.com/t/what-factors-affect-height/594032.md?page=2)