Your total kilojoule intake has the greatest impact on your abillity to lose weight. 
Exercise alone is not an effective way to lose weight.
Exercise assists long term maintainence and prevention of weight gain.
A hint for weight loss - Be aware of the sugar content in all food and drinks that enter your mouth.
A rule of thumb- look at the contents list on the packaging - its acceptable if  less than 5g  of sugar per 100g serve.
How much sugar per day - 30-40g.
Remember its only 2 serves of fruit per day. It's good for you but its also a sugar source.