It's normal to have "stubborn" fat that seems to stay the same size even when you lose weight and lean out everywhere else. For men the lower abdomen is the most common site for this especially men with low testosterone levels.
People who aren't very fat that go on low calorie diets for long periods of time will lower their metabolism so it becomes closer to maintenance and that's a big reason why diets tend to stall. 1600 calories is a bit low for that, though.
What's your workout routine like? Also a diet breakdown would be helpful. A lot of people overestimate their exercise and think they're eating less healthy than they think they are. Also, paradoxically working out too hard can cause you to stall as well.
There's also a few medical issues that can be problematic as well. Ever have your testosterone or thyroid levels checked? Or have any GI problems like frequent constipation or diarrhea?
Another simple trick you can do is drink as much ice water as you can. Obviously not 5 gallons a day where you get hyponatremia, but your body has to expend energy to keep your body warm so it's an easy way to burn calories while sitting at your desk
I have never had my testosterone or thyroid levels checked, but I can tell you I was very skinny up until a few years ago before eating out all the time and eating large portions fucked me before I realized it. If you would like to take a look at my diet just shoot me a PM and I can add you on myfitnesspal if you have an account.
No constipation or diarrhea.
Would it be better to eat like 2200 a few days then go back to 1600? Keeping my metabolism on it's toes? I was really surprised at how bad I was eating when I got myfitnesspal, I thought I was doing good but in reality I was doing shitty.
Workout usually consists of the following.
Day 1:
Dumbbell Curls (starting at 35lbs, 3 sets of 6 to 8 and work down to 20lbs)
Tricep pulldowns machine (starting at 90lbs, 3 sets of 6 to 8 and work down to 60lbs)
Military Press Smith Machine (starting at 40lbs - the bar, sets of 6 to 8 until I can't do anymore)
Shoulder rotation pulldowns cable machine (starting at 60lbs, 3 sets of 6 to 8 and work down to 40lbs) unsure of proper name
Shoulder shrugs ( 40 or 45lbs, 3 sets of 15 to 20)
Shoulder flys (20lbs, 3 sets of as many as I can do each set)
Standing side bends (45lbs, 3 sets of 20 for each side)
Situps Excercise ball (25 a day if possible)
Day 2:
Bench Press Smith Machine (35lbs - the bar, 3 sets of 6-8 and work down to 20lbs. 3 sets close grip on each weight as many as I can do)
Incline Bench Press Smith Machine (25lbs - the bar, 3 sets of as many as I can do. I usually go down to 20lbs and do as many as I can do until I can't anymore, exhaustion kicks my ass at this point.
Rowing type machine (80 to 90lbs, 3 sets of 6-8)
Pull down machine (80lbs, 3 sets of 6-8)
Dumbbell back flys (25lbs, 3 sets of 6-8)
Chest flys (35lbs, 3 sets of 6-8 work down to 25lbs)
Leg extensions (110lbs, 3 sets of 15)
Reverse leg extensions (100lbs, 3 sets of 15)
Squats (35 or 45lbs, 3 sets of 10) I also rotate between the leg press machine every other leg day.
Calf raises (45lbs, 3 sets of 20)
Standing side bends (45lbs, 3 sets of 20 for each side)
Situps Excercise ball (25 a day if possible)
EDIT: Reverse leg extension might be called hamstring curl.
