I was 63 kgs after my a level exam. I really didn't want to go to uk all fat so i told my mum that i wanted to lose weight. her plan for me was:

exercise for at least 1 hour a day
no carbs for the first 2 weeks (this includes no fruits, no white bread, no rice) i basically had veggies (no dressing) and chicken/fish/eggs for those two weeks..
healthy diet after the two weeks, with exercise

i ended up doing 2-3 hours a day on the treadmill, just walking, no running. i managed to lose bout 7 kilos in 2 months camtu.. then in the third month (just before i flew to uk) mum enrolled me for this slimming programme to mainly tone up my body(cause my bum was still quite big) and i didn't lose any weight, but i did lose some inches. so it was definitely worth it..

and now, in my second year, i've lost bout 2 more kilos cause of the busy schedule and other sports im playing now. and now that my weight is sort of maintained, i can eat junk food occasionally and still not gain weight

so, all those no carb diets do work. but dont keep it up for too long cause its not good for ur health.. but exercise is definitely good!!

but do be prepared to feel very nauseous the first week of eating no sugars