What are the main causes of cellulite?
The following diagram graphically displays the main causes of cellulite:
Why did you present "natural estrogen" as one of the major cellulite-causing factors?
Estrogen is the reason women develop cellulite and men don't. This is because estrogen stimulates the proliferation (multiplication) of adipocytes (fat cells) in the subcutaneous tissue (lower part of the skin) of the thighs and butt, and sometimes that of the calves, stomach and upper arms. Without estrogen those cells do not proliferate excessively and therefore you don't develop fat pockets underneath your skin. Men who eat too much or sit on their bum may become fat or flabby, respectively, but do not normally develop cellulite. Men only develop cellulite when their body starts secreting excess estrogen. This only happens when they become overweight and/or old and their body transforms too much testosterone into estrogen, via a process called aromatisation, or when they change sex (male to female transexual).
Needless to say, of course, that the worse type of estrogen, both in regard to cellulite and cancer, is artificial estrogen, in the form of contraceptive pill (mentioned above as an even stronger cellulite factor than natural oestrogen), xenoestrogens from plastics and hormone replacement therapy (HRT).
Furthermore, pregnancy is a leading cause of cellulite due to the very high estrogen levels secreted by the body during that period.
Why did you mention inactivity separately to "calorie surplus" as a cellulite-causing factor? Isn't it all the same?
Nope. Even if you a follow a perfectly healthy diet you will still develop cellulite if you sit on your bum all day. This is because inactivity causes the proliferation of adipocytes at the expense of fibroblasts (collagen cells), regardless of calorie surplus or not. This simply makes you flabbier and fatter on the surface, i.e. more cellulite-y. In addition, inactivity slows down your blood circulation and lymphatic drainage, further exacerbating cellulite.
Similarly, if you exercise a lot but your eating/drinking habits are so excessive that you manage to accumulate a calorie surplus every day, you will also develop cellulite, regardless of how much you exercise.
To be precise, it is binge eating/drinking in combination with inactivity on the same day that causes the most damage, rather than a small daily surplus throughout the year. This is because under those circumstances your body literally "dumps" the excessive calories straight into your fat cells - including your "cellulite fat cells" that by nature are designed to act as fat traps.
What about heredity?
Heredity also plays a role, but to develop cellulite you do need excess calories and/or inactivity, PLUS estrogen, the main preconditions. I am certain that cave women did not have cellulite, regardless of their mum's genes, simply because they did not have access to doughnuts, computers, estrogenic chemicals from plastics and chemical contraception, among the other presents of modern civilisation. You simply cannot develop cellulite if you walk all day and eat loads of veg and lean mean, fish, berries and nuts - like our stone age ancestors did.
Why is caffeine shown as a minor cellulite-causing factor?
Because it is. Caffeine can potentially cause cellulite INDIRECTLY, due to the stimulation-exhaustion-stimulation pattern it's cyclical use causes to your metabolism, and possibly due to your kidneys becoming dependent on it for water elimination, leading to water retention. However, the evidence on both issue is quite thin.
On the other hand, caffeine is well-known as an anti-fibrotic chemical, and that should be protective against cellulite, to some extent at least.
So, in summary, I would say that only excessive caffeine may cause cellulite, and that is not even a major cause of cellulite, anyway.
OK, now that I know what causes cellulite what can I practically do to reduce it?
Well, avoiding the causes is always a good start! So start by eating healthily (organic, if possible), exercising a lot and avoiding chemical contraception, smoking and excessive drinking. And then add to the mix a quality anti-cellulite cream and, if possible, some intensive cellulite treatments.
And if you are 22, just remember that prevention is always better than cure - you will not remain 22 years' old forever :)