Diet versus exercise, what contributes more to pure weight loss?

dieting, always. if you're talking about strictly weight loss, your diet is the most important thing. weight loss and gain is all about calories in vs calories out. and you burn a lot of calories normally throughout the day. a woman at 130 lbs and 5'8" at 30 years old burns 1400 calories throughout the day normally. you need to figure out your base metabolic rate, and adjust your calorie intake accordingly, and then supplement that with exercise. But it's not really healthy to have an adjusted diet without an exercise regiment, because you simply wouldn't be getting enough nutrition. with as few calories as you'd be taking in like that, you'd be low on protein or carbs or vitamins, no matter what it is, you'd have some kind of deficit, and more than likely, you probably wouldn't feel too great. so the smartest thing to do is to eat to get the nutrition you need, despite the calories involved, and then work to get those calories knocked out.

Base metabolic rate formulas:

Men: 66 + (13.7 X weight in kg's) + (5 X height in centimetres) - (6.8 X age in years).

Women: 655 + (9.6 X weight in kg's) + (1.8 X height in centimetres) - (4.7 X age in years).