Eat more fat. Butter up those veggies, pick fattier cuts of meat, have some eggs, etc.
Lots of newbies end up eating way too many nuts in the beginning (this guy included).
Keep them down to a handful a day and look for satiety in more balanced foods.
You may also be experiencing "carb flu". Type that into the search box for more info there.
Your body might be protesting the lack of carbohydrates which you interpret as hunger.
Stay strong and you'll reap the benefits of what Mark calls being "fat adapted".