For losing weight, diet is much more important than exercise.

Studies have shown that very few people can successfully lose weight through exercise alone, and that dieting is much more effective.

Which is easier, cutting out soda and sweets or running every day? Keep in mind that running one mile burns about 100 calories. Dessert can easily be upwards of 500 calories. https://www.healthline.com/health/fitness-exercise/running-b...

Also, exercise stimulates hunger and you will naturally eat more to compensate for the lost calories.