Fast food on a diet?

No need to feared something had happened. But according to the principle of input-output. That obesity will occur when consuming more calories than spent. Although workout, but after that consuming excess calories. The alternative way is to remove the calories you have entered by way of a little exercise or eating less calories at your next meal. But the key is to enjoy life. Excessive calorie intake is only once, will not much affect the diet.

Nearly all diets are about portion control. Fast food won't hurt your diet. The bigger problem is the salt intake or the sugar in the drinks. Even then portion control is a factor.

If you're eating less calories than your body burns, you will lose weight. Science.