There is a lot of debate in this matter. Is exercise alone better for weight loss? Or is dieting alone good enough?

There has been a study on this exact subject and the results were that both gave the same results.

The study appears on the Journal of Clinical Endocrinology and Metabolism (abstract).

This study involved 35 overweight people which were in healthy condition beside there weight. The 35 people were divided in two groups. One group reduced there calories by 27%. The second group were told to have a reduced diet of 13% and they had to do enough exercise to burn another extra 13% calories.

Result

Both groups lost in average of

• 10% of body weight
• ~24% of fat
• 27% of belly fat

My personal opinion is that if people want to see great results, then they should always combined exercise with a balanced diet. You should never put yourself in a position were you have to choose between exercise or diet because both are essential.