Whats more important: Diet or Exercise?

Diet.

Neither, they both are. They both work together.

You can't out train a bad diet.

#truth

...why not do both any way ? It will be better for you.

well, yes... this would be best

Diet. You can't make up for a bad diet with exercise.

Diet, probably. Certainly if you have a lot of weight to lose.

BUT I think the importance of exercise increases as you lose more weight, because diet alone won't shift the last stone or so, at least that's what I've found anyway. I had 2 stone (28lb) to lose, the first 11lb came off when I changed my diet without doing much else, but I found I needed to increase my exercise and do the right exercise to start losing the second stone.

Exercise has also changed the look of my body, increased my self esteem and improved my health (cardiovascular fitness, endurance etc). So, I think exercise is particuarly important for keeping the weight off. Improved fitness means you want to do more, to challenge yourself, maybe try new types of sport or activity, because you are physically more able to. Increased self esteem from improving at your fitness goals, or the social aspects and accountability of being part of a team/fitness group or club means that you are less likely to comfort eat and fall back into bad habits. Improved body composition has health benefits such as being at less risk of heart disease, hypertension, diabetes and even certain cancers, because you reduce the visceral fat around the organs. Exercise combined with healthy diet is more successful at reducing this kind of fat than diet alone.

I also tend to think, not from a particularly scientific point of view but more from my own experiences, that when you take a holistic, long term view to losing weight, and you do it to improve your whole body and life not just a scale number, it tends to be more successful for longer than people who just "go on a diet". And this is just what I've observed really from the type of work I used to be involved in (health promotion campaigns) and from observing friends and family try and lose weight.

Both go hand in hand. One helps with maintaing a healthy life, one builds strength and endurance. Diet is #1 though.

You can't out exercise a bad diet....

not to say one can't have indulgences, but it needs to be balanced-not ruled by indulgences with occasionally eating healthy.

As far as dropping pounds, every little thing I eat makes a big difference. So I'd say diet. Exercise is definitely necessary, but if I am eating unhealthy foods or simply too much food, the cellulite and fat rolls and pounds aren't gonna budge. I exercise to burn calories so I can eat a little more (and of course to gain muscle and strength, etc.), but I do a lot of yoga simply for my MENTAL health. And when I'm healthier mentally, I can make better eating choices. So they go hand in hand, but diet is probably a little more important if you want to see pounds drop fast.

Diet and exercise go hand in hand for total health. Someone said 'you can't out train a bad diet'; this is true! Good luck!