When you are losing weight for more than a month, I guarantee you, if you are a reasonable person, you wouldn't be losing a donut with those 500 Kcal. You'd instead be giving up 500grams (almost 2 pounds) of tomatoes + 80 grams of cheese + slice of wholegrain bread. That's a meal right there.
BTW, training during weight loss (by caloric restriction, at least) is mostly done to keep your existing muscle mass + keep metabolic rate up. You wouldn't train to create a bigger deficiency. So every calorie you burn through training (even low-intensity) you should intake back as food.
I will be walking for about an 1.5h tonight to "gather" some calories for dinner. I spend my rations for a bit more caloric lunch and now I will have to pay for it. :)