I often recommend this for many purposes (3 gram of l-tyrosine) a good hour after a meal as it increases dopamine levels in the brain. When dopamine levels are high, hunger is decreased and example would be when or if you take amphetamine, it sky rockets dopamine up super high and cuts appetite.
But modafanil as mentioned but hard to find... Would work great, have yet to try it, but it's a common effect.