What are you referring to here, exactly? General problems with body image, or something more serious, such as anorexia, bulimia, or binge-eating?
Before anything, if you don't understand what body image issues means, I once heard an analogy that might help. Start with the idea of
perceptual bias. The example was, what if you had to wear a really ugly t-shirt or something equally ridiculous over your normal clothes, and then asked to give a presentation? The presentation is unrelated to the shirt, but most people will be still having thoughts about that shirt even though you are doing something unrelated. And if asked what you thought your
peers thought about that shirt, you will think your peers remember more about the shirt more than they actually do. Replace the shirt with "body size", and there you have it.
Many girls have - I wouldn't say "body image issues" because it kind of trivializes what could on the whole be a much bigger problem - but let's start with an inaccurate perception of their body. Most of this stems from, as someone already pointed out, culture. The images this culture directs at women have a lot to do with body - slim models, celebrities with perfect bodies and hair, diet plans (your life will suddenly be this much better if you only lost X number of pounds), bikini models, clothing... a lot of what is in our culture is beauty pressure.
But this clean 1 minute video says it all better than I ever can here:
https://www.youtube.com/watch?v=Ei6JvK0W60I
So some girls may feel a lot of pressure to stay thin. Because that's desirable (as advertised) and praised. For example, I once read an anecdote about a woman who was a lawyer, she's accomplished all sorts of things in her work, she's heading all these great projects... and yet does anyone compliment her on any of this? Sure. But she notices that she gets way more compliments about how thin she is way, way more than anything else. So the massive percentage of compliments she gets is about her weight, her figure... rather than these real accomplishments. So in culture at least on average,
a thin appearance is enviable and praised.
The problem is when girls start getting wrapped up in this sort of thinking. Young girls who come to associate getting compliments about their thinness as a self-affirmation, as a matter of self-worth. This is also the group most prone to self-appraisal and social comparison. This may seem silly to some guys, but it is how some girls get to feeling after all the cultural bombardment. You're more likely to be complimented on your looks because it's easy. And suddenly here is something that you can control. Being thin = more self-worth, more praise. It seems to be how culture measures your worth, I mean, look at all the bikini ads!
(There was a presentation in which a psychologist did just that, showed pictures of bikini ads, and one of those pictures was a larger woman in a bikini. She noticed the audience chuckling uncomfortably at that picture, or just looking away. Instead of glossing over it, she stopped there, and started questioning the audience why? Leading to a discussion of this stuff. Every presentation she does this)
Body dissatisfaction is another problem. Where does it come from?
It was found that you can manipulate body satisfaction after having people, for instance, view fashion magazines versus viewing non-fashion ones (women who viewed the fashion magazines had a lower opinion of themselves). Therefore, the issues of body image tie into issues of self-esteem as well. Also, this is
not limited to girls. Reading muscle and fitness magazines, looking at biologically-impossible super-muscular action figures, all correlated to body dissatisfaction among males as well. Males also have culturally-mediated standards they may feel pressured to meet, it is not confined to women.
For anyone who thinks media images are not a problem, there's a study called
The Effect of Experimental Presentation of Thin-Media Images on Body Satisfaction: A Meta-Analytic Review (Groesz, Levine, Murnen) I can direct you to. As to whether media effects are the real problem, there was an experiment done by Groesz where they went to the island of Fiji, whether these people's values encourage a more robust appetite. So this was in 1995, and they introduced TV to Fiji, then interviewed adolescent girls before and after. These girls all expressed admiration for specific TV reality-show characters, and more importantly, reported later that they and their friends now feel differently about body weight and shape (83%) of them. 3 years later, you suddenly have a small percentage of these girls who had never done these behaviors before, suddenly
throwing up to control their weight.
What do media images do? First, it gave these young girls unrealistic goals. Also, as the characters in the shows were presented as affluent, suddenly beauty and body size and thinness becomes associated with social influence, power, and mate choice... because the men in these shows were always paired up with the prettiest girls.
So "body image issues' stems less from just fearing weight than something else, something bigger. And that's when you start to segue way into anorexia, which is a whole other can of worms.
** Before I go any further: If you are dating someone who will not eat publicly, in fact refuses to eat and denies hunger (denial of hunger is not an absence of hunger!), engages in weight-suppression behaviors to the extreme, denies there is a problem with any of that, really fears gaining weight, exercises to an extreme degree (see Portia deRosi on youtube), is apathetic, withdrawn, or depressed in mood... it might likely be a bigger problem, and this person needs HELP more than your compliments. In addition, starvation can also skew the thinking, reinforcing it's own behaviors. **
Eating and body weight can also be less about body IMAGE than they are about bigger problems with control, power, or anxiety.
Examples:
- Hunger strikes as a response to a situation you feel you have no power over, hunger strikes as a response to someone, something that wronged you.
- Self-starvation and denial of food to yourself as an exercise of control and self-disciplined that may make the person doing that feel successful, better than others because they can control their bodies in ways the average person can't.
- Perhaps there are areas in someone who has these severe body-perception issues, areas in that person's life that feels out of control, or too complicated, or life feels like it's too damn MUCH, and NOT eating boils down all these issues to just one - the fight to not eat, something that you can emerge 'victorious' in. If this sounds like depression, anorexia
is comorbid with depression.
- Or maybe not-eating and controlling your body shape (I think these all tie in with body image issues), is being used as a way to reduce anxiety. Again, there are all these complicated, terrifying things going on in life right now, boil it down to not-eating, control it.
- Or what if our person is a perfectionist (statistics say many anorexics are), and of course the pursuit of perfection is both time-consuming but also impossible as no one's perfect. But what if that person sees perfection (of body, as in all things) as a real, noble state they have a right to pursue? There is the expectation that you excel (you must excel, get perfect grades, because that is who you are, and people will like you only if you succeed their expectations), the guilt of feeling as if you don't deserve how you are treated, the desire to please, to be accepted by someone who can never accept you as you are, the feeling that, by not eating, you can starve away loneliness and uncertainty. You want the narrowness of attention (if your thoughts are preoccupied with only food, for instance), you don't and you can't think about the other concerns.
I certainly don't wish to speak for someone with anorexia, but these are all things that have been brought up in my classes on the subject and through my own experiences. Body image "issues" certainly differ in the spectrum of severity between people, and of course anorexia presents differently depending on the person as well.
But overall.
To the person who asked why do women have body image issues... this. All of this. It's not simple, it's not laughable, it's above all not petty. It's not just about appetite, or looking "pretty", it's a response to culturally-instigated propaganda, it's a search for self-worth, it's a lot more than just beauty.
There's more to all this, but since I'm taking this thread as a discussion of body image issues I thought I would bring it up a little bit. As a girl who has dealt with borderline-anorexia and have known family who have dealt with much worse and have studied this topic for some time in uni, I feel that the need to just... throw it out there that "body image issues" may or may not actually be something more serious. Just keep that in mind and be a little empathetic to your girlfriends, I think, and that should help.
To the 5ilver who wrote, "What I would have liked to hear more than anything else, 'I want to help you'", I think that's right. On my part, that is exactly what I would have liked to hear. Not all of the assurances that you're fine as you are (you may not be, psychologically speaking), but that someone wants to help, someone who asks
What's wrong, and
How can I help? Also, you don't deserve what you're inflicting on yourself. Without judging or dismissing the problem as petty.
Also, I think that if compliments are genuine, they will help to. I don't know about getting too many compliments that it... cheapens, because I don't get compliments, true compliments, all that often so I tend to value them. But that's me.
To the person who wrote -
"Share food. But really don't. Sandwiches and pizza are good for this one. Take minute bites and pass them strait back. That way, because the food is being shared, more of it can be eaten. If you are careful this can mean you get a decent meal into someone. Sneaky? Mean? Someone might get angry with me? Don't care." That is... sneaky and underhanded and very smart.

No matter the means, it's more important first of all that she doesn't starve, and if you have to resort to a bit of trickery to get her to eat, I say it's worth her... not dying.
For anyone who is interested in the subject further, or just wants to increase their empathy a little, I can recommend the books
Brave Girl Eating, and to a lesser extent,
Dying to Please and
Appetites (by Caroline Knapp), although to a lesser extent because the last two are not as psychologically sound, more feelings oriented, while
Brave Girl Eating is more practical and straightforward, which is why I prefer it.
So yeah, just my two cents on the matter. I usually lurk these forums without an account but this topic just sort of hit the nail on the head for me.