How do I reduce the size of my thighs?

Running can be done on a treadmill or on the ground outdoors. This can give you the cardiovascular exercise necessary to burn the fat in your butt and thighs. If you do not like to run, do any form of cardio such as cycling, swimming or elliptical training as long as your butt and thighs are involved. Work out for 45 to 60 minutes, three times a week.

I would defiantly recommend doing a lot of jogging, and/or running, walking etc.

Also, do a lot of squats, every day.

Drink lots of water, also, you can add lemon [juice]to your water, it gives it a nice taste AND the natural acids in the lemon help to burn fat ... overtime of course.

Instead of snacking on crisps, biscuits and cakes. Eat some mixed nuts, raisins, and prepared fruit:

apples, grapes, raspberries, blueberries, bananas etc. Anything you like.

If you're still hungry. Have more!

Also, eat a lot of vegetables too.

Smoothies are also good, make your own with fruit and yoghurt etc. in a blender.

Good luck!

Exercise is your best bet. You can use things like fat burners, creams etc. To help intensify the effect. Cardio also looks like your best choice.