If you really are eating "no carbs", you'll be in ketosis. Although pretty grueling for the first 48-72 hours, your blood sugar will quickly level out and you'll have a much more balanced energy level throughout the day.
You'll want to really avoid high glycemic index foods. That would include (basically) any carbohydrate that is not found in its natural state. If it went through a factory of any type before you ate it, chances are it's been "processed", stripping away natural fibers and husks. The more pre-digestion that happens in a factory (such as smashing wheat into flour), the less your body has to do, and the quicker it can be absorbed into your blood. That in turn spikes your blood sugar, dumps insulin, and enhances fat storage.
If fat loss is your goal, you should:
- Avoid carbohydrates as much as possible. Even by doing that, you'll still get plenty.
- Absolutely avoid any carbohydrate that is not found as it was in nature. Unless you can find a "flour tree" with little bags of flour growing off of it, don't eat flour.
Track your calories for a week or two with something like myfitnesspal or dailyburn. Focus on reducing the carbs, upping the protein, and scattering food throughout the day every few hours. Low carb induced ketosis combined with smaller high protein meals means I can go weeks without ever feeling hungry.
Get your diet nailed down and the energy level will take care of itself.