keto diet for my 15 year old sister????

she has been eating my head that she wants to loose weight. i realy feel sorry for her man.. shes 160 over weight. only 5'3. thing is i realy want to help her but shes young.. turning 16 in 2 months.. well im thinking about putting her on a diet and teaching her what to eat or what not to eat and how to eat... almost no carbs high fat and protien.. i dont want her skin to get saggy.... i also do not want her to take any weight loss drugs... so im thinking about making her drink plain coffee.. for apetite control.. thing is coffee contains sodium... so in confused here.. well if u have sodium in your body and drinking loads of water will kill all that sodium... what about gluecose??? it ofically turns into gluecose.. will water break it down and kill it?? im willing to take her to the gym with me and training together... to help build her self esteem.. she would even cry at times "im too fat im too fat" realy breaks my heart. shes my only sister and i love her to death... is she too young for a keto diet??? i know its realy hard but i also know she has the will power to keep up with the diet. so guys?? what do u think?? please let me know b4 i make any mistakes with her diet since shes a girl. :)
thanks everyone.

ps: im on a keto diet for the past 2 weeks and i got amazing resluts... love handles shrinking went from 215 to 205 muscle is being maintained... vascularity is slowly showing.. hehehe :lol:

keto diet is the high fat and protein diet correct?
how old are you?

in my opinion before putting her on a diet like that i would get her to get a dr. appointment,check thyroid function and blood work to see if a problem with her metabolism.
after that talk to dr about a diet
at her age you have to be very careful as bodyand mind is still growing...a diet is a good idea except dont call it a "diet". diets cause yoyo weight gains,loose a bunch and gain it back-- change her way of eating and living..make it a lifestyle of well balanced foods,cutting out simple sugars and have her do cardio.
you never mentioned if she works out or does cardio also never mentioned her eating habbits now

start simple,a well balanced diet with cardio and light weight training--cutting out simple sugars--and remember you want fat loss not just weight loss

any change in diet or lifestyle can cause weight loss,do this till it quits producing results(body gets used to it) before considering any questionable options

im all for the keto diet its great... but make sure your sister can supress those cravings i know my little sister who eats shit food nonstop could never go on keto.... other than that as long as she follows the diet, and gets plenty of exercise, she should be fine...btw since your sister does not workout (im assuming), you might want to put her on the atkins diet instead of keto (its pretty much the same thing, but atkins was designed more for sedentary people)

She too young! and my only assumption is that the results of the keto might aggrave a teenager acne!!!!!

im 25, popping acne like on a 10 000mg of test a day cycle! damn it!!!!!

believe me its bad!

also, the side effects would be not really nice
bad breath
alway going to bathroom

try to teach her a good basic and exercise