painjunkie

It is normal. I think it harks back to a time when our bodies were being trained through the flight or fight response (we were about to get some food or be food).

The body's possibly become aware that showing signs of hunger in such a situation would'nt be helpful (detract from what needed to be done), so it curbs it.

In some the [temporary] appetite suppressant effect is clearer than in others.

However, the running you've been doing has trained the body to look to it's fat stores for energy needs (rather than glycogen), so hunger response is not being as often/strongly triggered. It's usually intensity or a change in exercise that initiates this effect. This (the lack of appetite) will diminish gradually over time as the body adapts. And you will regain your appetite.

Good thing is that cravings for less healthy foods also subside as well at this stage.

Your breathing patterns are going to be stronger (with deeper breaths). Your VO2 max levels is likely to be improved.

Eat regular, often and small meals (every 2 to 3 hours) in spite of the lack of hunger. Enough to replenish blood and muscle glycogen levels but not more (ie, so it does'nt store excess food as fat). Also drink plenty of water.

Even if fat burning and fat storing modes are not mutually exclusive (ie only one can be happening at the same time), if only enough calories are being taken in to meet current needs, there might not be anything to be stored anyway.

HTH.