That’s a very tiny amount of food for an average adult male. There are plenty of online calorie recommendations but 2000-3000/day (depending on exact height, weight, activity level and so forth) would be in the ballpark.
You can certainly lose weight by cutting calories drastically - if you were staying at the same weight on a 2500 cal/day intake, doing nothing but chopping it to 1000 cal/day would theoretically put you on pace to lose 3lbs of fat every week. All of the recommendations I’ve ever seen for healthy, maintainable weight loss for someone who is basically healthy to start (that is, not really obese) are in the 1-2lb/week range.
However you still need to get enough actual nutrition to keep your body in good shape and I’d be concerned that a very large reduction in food intake could adversely affect that side of things. I think it’s far better to cut out the junk food, eat a sensible amount of healthy food and increase activity level gradually - that’s also maintainable in the long run which is (IME) the toughest thing about weight loss; anyone can drop X lbs in some amount of time, but doing it in a healthy manner and then keeping it off long-term is the real challenge.
Going back to the OP, every month Runner’s World seems to have some new study showing a completely different trend in “what works best”; one month it’s longer runs at a moderate pace, then next month it’s “run like hell for 20 seconds, rest 10 seconds, repeat for 4 minutes” (that was an actual program)…I started out walking, adding running in gradually, slowly built up my running distances (again, a common recommendation is don’t increase more than about 10%/week) and as I increased the distances that led me naturally to more varied terrain (I’ve no desire to do 10 miles on a track) so hills got into the mix. My speed just built up over time without any conscious effort on my part to “run faster”. Don’t go farther/faster than is comfortable for you or you’ll wind up with nagging injuries. Once you’ve got a good solid base (couple of miles a day, 3-4 times per week) mix things up, you can do sprints or find some gentle hills and run up/walk down those, that kind of thing. I find that the speed work increases my explosiveness (such as it is) and makes the longer runs easier because I’m going at a pace lower than my maximum. Recovery is better for similar reasons.