It can be hard to get the diet and nutrition balance right with teenage girls. First, boys are less concerned with their appearance, and are more likely to eat anything and everything.  Second, their growth spurts start later and lasts longer, so boys can eat you out of house and home for a decade. Conversely, if girls are eating voraciously for a decade--and they’re not at sports practice daily--there’s likely a psychological issue. Ask her directly--why do you eat so much and what benefit is it providing?  Even if you have not been able to control your own compulsive eating, it is your job as a parent to not pass this dysfunction on. Work with your girls and strategize: can you trade Gatorade G2 for Coke?  Can we eat fudgesicles instead of cheesecake? 

In particular, girls who start maturing before age 13 are more likely to have problems with their weight as teenagers than girls who mature later. With females it’s imperative to set good examples by kindergarten (but it’s never too late). The most important lesson is fruit or vegetables at every meal!Throughout their lives, women who eat large portions of fruits and vegetables and moderate portions of other foods reduce their cancer risk by 2/3 and are almost never obese. 

On the other hand, girls are more likely than boys to become vegans and anorexics. Yes, in teenage years these conditions are related. I don’t care if I offend you—raising children vegan is child abuse. Every study on the subject finds that children on strict vegan diets suffer lower IQ, reduced growth, shorter attention spans, physical weakness, and even teasing.  Female bone mass is mostly established by age 18. You cannot go backand undo all the damage done by starvation and poor nutrition during puberty—unfortunately your skinny vegan daughter is at permanent risk for early-onset osteoporosis and dementia. 

No matter their careers, most women do have children. Teenage girls need to understand they are entrusted with providing the best possible environment for a developing child in the womb and while nursing.  I recommend starting with the following supplements as early as 11: 

--1,000-3,000 mg C

--1,500-3,000 i.u. D if winter or not in sun twice a week.

--500-1,000 mg calcium

--250-500 mg magnesium

--Two (2) grams high DHA fish oil

--“Super” multivitamin/multimineral

--800 mcg folic acid

--100 mg alpha lipoic acid