If he was obese before eating anything low carb then it probably is the high carb diet that is causing his obesity. I will bet that it is a high crab evening meal that causes the morning pastry cravings.Atleast by consuming a carb balanced diet in the evening, he will not have a spike in insulin which results in a drop in glucose. He may find out that he doesn't crave the morning pastries anymore. I think that going with a low carb meal in the evening will give him a nice edge at reducing his overall carbs altogether.