Hi Paul,
To lose undesired body fat, you need to create a calorie deficit. That means, knock off 200 to 400 calories at the end of the day (so you have energy to function during the day). Your body has a hard time building muscle when you are in calorie deficit, but you can help minimize muscle loss by strength training while in calorie deficit.
You do not need glutamine, nor a gel.You just want to eat standard foods, preferably a carb + protein combination, such as a yogurt (for a recovery snack) or a balanced meal (cereal and milk, a sandwich, a dinner) shortly after you finish training.
For additional information on how to lose weight and have energy to exercise, as well as how to recover from your workouts, you might enjoy to read my Sports Nutrition Guidebook (2008).
With best regards,
Nancy