nutrition

It's pretty individual, but if you are struggling on long runs, then I'd definitely experiment with putting a little "gas in the tank" before a run. Personally I feel a lot better if I have a snack (usually granola bar and coffee) before any workout that lasts longer than 30-40 minutes, especially since 90% of my run and bike training is early morning (about 5-6:30 AM). Otherwise my energy flags and I get hungry, which is annoying! There are a lot of variables that affect whether you would actually "need" this (what/when you ate the night before, metabolism, intensity, etc.) but if it makes your runs go better, do it. (Caffeine helps too, especially for morning runs!) Normally I also take a gu for anything 90 minutes or over, and have it at about halfway.

There are different ideas about training in a fasted state, but I wouldn't do it for a long run--it will feel sucky and possibly hurt your ability to recover. If you feel okay doing that for shorter workouts of an hour or less, do that--might help with weight loss or fat-burning. (That's never been a goal of mine, so I don't keep up on current thoughts on this--could be mistaken.)

I always eat something before a run. I am a plant based athlete so I predominately live on carbs. Our bodies run on predominately carbs.

I eat a grapefruit/orange and/or a banana about an hour before anything longer then a 5K. For runs approaching 1/2 marathon and longer, I will also add in a couple potatoes. (Slice them up. microwave and vegan butter) You need to give the body some fuel.

Also as a note, running to lose weight is a difficult thing to do. The more you run, the hungrier you will become. If you try to starve yourself of calories you will be lethargic and set yourself up for injuries as your mileage increases. I lost 90lbs on a plant based diet, but as my running increased, (ultimately completing 2 full marathons within 4 months of each other) my weight loss stagnated at 170lbs, 20% body fat for over a year.

As soon as I stopped the high volume running and training, the weight loss started again. Down to 165 and 17% body fat, but unfortunately for the fat loss, its high volume training season again. I have 3 triathlons in August, so I only have about 2 months to really ramp up my training for my 'A' race mid August.

All weight loss will come from the following formula: 80% Nutrition, 20% Exercise, and 100% Attitude!

Now Fruit Up and RUN!

You've already gotten some good advice. Andyou may already be doing this, but if not, make sure you're keeping a log. What are you eating and when, the temperature, the course you're running, etc. In doing that, I found that where I was running into trouble was what I was eating/drinking the night before. Getting older kind of sucks that way. :P But even more than that, it was trying to run longer when it started getting hot/humid. So for me, hydration.

I used to hate morning runs and discovered it was due to nutrition. I just felt lazy and weak. Since I like to keep some definition a personal trainer recommended to go protein over carbs in the ams before runs and it helped energy wise than going empty. I usually eat a couple boiled eggs or some lox (though their high in sodium and baked salmon is better). Carbs are essential fuel but like others said if you're in it to lose weight you might want to limit the carb loading appropriately.

It is VERY individual, but I will give you my personal recipe for success:

Go grains early and sugars late.

For me, grains like teft a couple hours before my run/event or a whole wheat toast with PB on it seem to work wonders as far as getting to/keeping an even energy level, and then during exercise sugar in the form of gels or drink maintains.

Oly distance I just run my drink (skratch) and dont bother with solids during the race, longer I run blocks on the bike and gels on runs.

I did have to fine tune the when to eat gels bit by going out on long rides or runs and trying different feeding intervals to see where I stopped running deficits.

For me, my last food has to be at least 2+ hours before I exercise. So it makes it tough to eat much before I go. But, I've found through trial and error that if I'm much beyond 4 hours after I eat I'm too hungry and will do a banana.

Nutrition is key. But, so is sleep and recovery.

I'll agree with keeping a journal. I can be eye opening.

Practice what you think is going to work in the race. Then tweak it from there. Eat your race nutrition at the beginning of a medium run to see how your stomach can handle it. If your training is like mine, I don't have a lot of opportunities to practice full race nutrition so I experiment. I tried a fruit squeeze packet on my last long(ish) ride. Won't be doing that again.