If you have to choose, which is more important? I ask many people that & even some doctors. Most people think that exercise is very important. Well yes it is, but when it comes to weight loss, healthy eating beats it hands down.
Say you eat lots of food including a fair amount of junk & you make up this bad habit with plenty of exercises. Experts said it wont help. You might as well cut out the junk, cut out the excess sugar & carbohydrates.
Having said that, need to point out exercises is still important for general health. However when it comes to weight loss, dieting cum healthy eating still reign supreme :))