Long story short. I used to be around 250 lbs. Over the past few years I've dropped to about 185. But for some reason I still have a gut. Also, I'm 5'10 so I'm not really short where 185 would still be really heavy. Whats the deal?
Is the gut lose skin?
Did you lose that weight through exercise and changing eating habits, or did you decrease it by doing a lot of dieting/cardio?
The culprit in the "gut" distention is often omentum fat. You may want to google that "omentum".
Anyhow, a poor diet and and lack of good core exercise can often lead to this abdominal distention. With dietary and lifestyle changes subcutaneous fat tends to disappear quickest but the omentum, which is a sack like despository for fat and other metabolic wastes in the lower abdomen tends to be much slower at disposing or metabolizing it's contents.
You may notice some fat people have a rock solid and huge gut like an oak whiskey barrel, while some people store their abdominal fat on the oustide of the abdominal cavity making them soft and sloppy.
Overeating can cause the "stretched out slinky" effect to you gut as well. If you have weak core musculature and chronically eat till you are full, you can stretch out your gut to beyond it's normal dimensions, whether empty or full.
...or you may have a bad case of intestinal nematodes....does your bum itch? LOL
Great results already. Congrats.!! You really can't spot reduce a particular area. And fat cells shrink but do not usually disappear entirely. If you have a tendency to store fat around the guy, its usually the last place you will lose it, and you will only lose it if you get your body fat percentages down pretty low; at 5' 10", you might have to get down to 170 before you start getting the classic six pack, if not 165--and since you were so big at one time, you might still have a bit of loose skin. I'm 6' 175#, fairly lean, and if I put on 10 pounds, I would see most of it in my face and my gut, right along the love handle area. I lose my love handles completely at about 165# which was my old walk around in season HS wrestling weight before I cut down to 158 right before a match. It always becomes a trade off. The diet I have to maintain to stay at 165 is pretty extreme, while at 175, i still look damn good and it is much less effort, basically just requires working out.
if you still have a lot of excess fat at 170, then you might want to consider a minor lipo procedure. This is the classic indication for it, but at 185, your really not in a position to see whether you can trim down a bit with that last 15 pounds. That last 15 pounds is really the money weight if you are someone who stores the fat first in the belly, because a lot of your late weight loss will affect the early gain spots.
Core work does help in tightening the underlying muscles, but it won't spot shrink the actual fat cells. It might raise your metabolism a few clicks so that you've increased the calories eaten/calories burned equation in your favor. The cardio helps also but mix in some sprint and interval work because steady state work just tends to build efficiency, iow, you will start to burn less calories per minute worked. Intervals force your body to adapt to high intensity work loads.
Good luck with amazing progress so far.

